The night sky this month

Constellations, planets, meteor showers etc. on show this month.

The night sky in December 2018

posted 30 Nov 2018, 09:58 by Pete Collins   [ updated 30 Nov 2018, 12:07 ]

by Anne Holt

Sunrise      1st:    08.01       31st:    08.25
Sunset       1st:    15.53       31st:   15.59

Astronomical darkness
1st:  18.02 to 05.54       31st:  18.09 to 06.14

Latest Sunrise    30th  (08.25 from 28th - 31st)
Earliest Sunset   13th  (15.49 from 9th -17th)

Winter Solstice: 21st at 22.22.  This day is 9hrs 33mins shorter than at the Summer Solstice.
The shortest day is also on the 21st - 7hrs 28mins 29seconds.  The 22nd is less than 1 second longer.

New Moon:  7th at 07.20     Full Moon:  22nd at 17.48
Lunar apogee  12th at 12.27  (distance of  405176km)
Lunar perigee  24th at 09.53  (    "          "   361059km)

December's full Moon is known as the Cold Moon, no explanation needed. The Old English/Anglo-Saxon names are also self explanatory - The Moon before Yule or the Full Long Nights Moon.
In December, because of the angle of the ecliptic, the full Moon takes its highest path across the sky, opposite the lowest position of the Sun. The Winter Solstice this year is only just over 19 hours before the full Moon.

Highlights

Lots of lovely dark nights (fingers crossed for some cloud free skies) about 12 hours of astronomical darkness throughout the month.  We have the Winter Solstice and the shortest day - or, as astronomers prefer to think of it, the longest night, with 12 hours more astro darkness than in June.
There is one major meteor shower, the Geminids, often considered to be the most reliable of all, and several minor ones.
There should be a naked eye comet mid month, though it's failing to live up to the spectacular predictions made earlier in the year and will probably only be visible to the naked eye from a dark sky site - if that.
There are some bright early evening passes of the International Space Station in the first half of the month.
And we have a Christmas Star in the East! Venus is shining brightly in the morning sky in December. It will be slightly past its best by 25th but will still be brilliant, maybe bright enough to be seen in daylight, if you know where to look. It isn't recommended that you try to follow it, however, even if you do happen to have a camel and some gift wrapped gold, frankincense or myrrh.  It's unlikely to lead you to Bethlehem and, anyway, you'd be more than 2000 years late. And you would miss your Christmas lunch.

Constellations

Orion, with the stars of his belt pointing down to the brightest star in the sky, Sirius, is now well above the horizon by midnight, and is a beautiful sight especially from a dark sky site.  By month end these will be visible from 10pm - weather permitting.  Taurus and the Pleiades precede him across the sky.

Gemini, including the 'twins' Castor and Pollux, and Auriga with the bright Capella are also very prominent. Aries and Pisces, while not particularly bright - or often not even visible in our light polluted skies - are both quite high this month.

Perseus, Andromeda and the Great Square of Pegasus  are also well placed for most of the night. The Plough starts the night quite low in the Northern sky, with Cassiopeia high overhead.  Because of the long winter nights, these last two will have changed places before dawn as they rotate around the celestial north pole.

Planets

Mercury: in Libra. mag 3.0
A morning object, but not easily seen in December, especially at the beginning and end of the month. On 1st it rises at 07.04 just under an hour before the Sun but separated from it by only 8 degrees.  On 4th it is 2 degrees above the horizon at dawn and the following morning, when it will have brightened to mag 0.8, is just 7.5 degrees west of the 4% Moon as they rise about an hour before Sunrise.  It reaches greatest western elongation on 15th, when it will be at mag -0.4 and have an apparent separation from the Sun of 21 degrees. However, because of the low angle of the ecliptic it will be only 8 degrees above the horizon at dawn. On 16th it moves into Scorpio and into Ophiuchus on 21st, when it rises at 06.31 and reaches 7 degrees in the east before the sky brightens.  After greatest western elongation it appears to move closer to Jupiter - on 21st and 22nd they are less than 1 degree apart.  On 31st it rises at 07.10 and is only 3 degrees above the eastern horizon at dawn.
PLEASE REMEMBER:  Do not try to look at Mercury - or any other celestial object - through a scope or binoculars when it is low in the pre-dawn sky. Even catching the frst few rays of sunlight is likely to cause permanent eye damage.

Venus:  in Virgo, mag -4.7
At its brightest at the start of December, totally unmissable for those who can bear to leave their nice warm beds before sunrise. On 1st it rises at 04.07 and reaches 22 degrees in the east as the sky brightens at around 7.30.  On this morning the 17% lit Moon passes close to the planet.  It begins to fade very slightly after the first few days, -4.6 on 4th, but a little higher at 23 degrees by dawn.  It moves into Libra on 14th when it rises at 03.59.  On Christmas morning it will be a very bright star in the east, rising at 04.06 and easily visible from around 5am, when all those with young children will, no doubt, have been awakened  At month end it will rise at 04.12 and reach 20 degrees by dawn, still blazing away at mag -4.5.

Mars:  in Aquarius, mag 0.00
An evening object in December, visible from around 16.30 and setting about half an hour before midnight. Still easy to see despite it fading as it is still getting higher in the sky.  On 1st it culminates at 18.11, a few minutes after the start of astronomical darkness, at an altitude of 27 degrees.  On the evenings of 6th and 7th it passes less than one degree north of Neptune. Moves into Pisces on 22nd, when it culminates at 17.30, reaching 33 degrees in the south. By month end it culminates a few minutes earlier and a couple of degrees higher but will have faded to mag 0.4.

Jupiter: in Scorpio, mag -1.7
A morning object, not easily seen especially in early December, as it is very low in the pre-dawn sky.  On 1st it rises less than half an hour before the Sun and appears only 3 degrees from it. Its position improves during the month, on 7th it is only one degree above the horizon as the sky brightens, on 14th,when it moves into Ophiuchus, it reaches 4 degrees. By 25th it might be visible from a site with a low, clear south eastern horizon, at an altitude of 7 degrees at around 08.00.  By 31st it is slightly brighter at mag -1.8 and a little higher,  9 degrees in the SE at 07.35.

Saturn: in Sagittarius, mag 0.5
Very low in the evening sky, on 1st it is only 6 degrees above the horizon at dusk, setting at 17.47.  Not likely to be visible after the first few days of the month, by 18th it is on the horizon as the sky darkens and on 31st sets only a few minutes after the Sun.

Uranus: in Aries, mag 5.7
Still very well positioned for binocular observation, especially in the earlier part of December. It is also relatively bright - for Uranus - so it's a good time to try to spot it with the naked eye from a dark sky site.  On 1st it culminates at 21 14, reaching 48 degrees above the southern horizon, setting at 04.21.  Its apparent motion is currently retrograde (east to west)  and it moves back into Pisces on 4th. By month end it reaches its highest point, slightly lower at 46 degrees, at 19.14 in astronomical twilight.  A reasonable sized amateur scope should show the planet as a small blue/green disc.

Neptune:  in Aquarius, mag 7.9
An early evening object.  On 1st it reaches 28 degrees in the south at 18.27, during astronomical darkness. By month end it culminates at 16.30,  an hour and a half before it gets fully dark.  Still a good amateur telescopic target during the early evening, though a much larger scope is needed to show any markings on the blue disc.

Dwarf Planets

Ceres: in Virgo, mag 8.8
Should be visible in amateur scopes, especially in the latter part of December. On 1st it rises at 04.39 and only reaches 13 degrees by dawn.   On 5th it moves into Libra and is slightly fainter at mag 8.9.  It is about 3 degrees to the north of Venus on the morning of 29th and on 31st rises at 04.39, reaching 19 degrees before the sky brightens.

The other dwarf planets are so faint that they are only targets for experienced astrophotographers.

Pluto, In Sagittarius, mag 14.7
Not a good time for trying to catch this - it never gets higher than 14 degrees above the horizon during darkness.  By month end its apparent distance from the Sun is only 11 degrees.

Eris:  in Cetus, mag 18.8. 
Much fainter but might be a better bet. On 1st it reaches 34 degrees in the south soon after 21.00, on 31st culminates at 19.10.

Haumea in Bootes, mag 17.4
On 1st it reaches 35 degrees by dawn, and by 31st is at 50 degrees as the sky begins to brighten.

Makemake: in Coma Berenices mag 17.2
Should be visible in the early hours, on 1st it reaches 51 degrees by dawn, on 31st culminates at 60 degrees soon after the end of astro darkness at 06.38.

For more details and exact positions of all planets, asteroids and comets see:

Meteor Showers

One major shower this month.

Geminids:  active 4th to 19th. Some sources give the peak night as 13th/14th others say 14th/15th.  Actual peak, according to the IMO, is 12.30 on 14th with near maximum rates for several hours either side of this, so either night is likely to be a good time to look.  ZHR under ideal conditions (dark sky, high radiant, no moon) is 150, so we might see as many as 50 from a reasonable site, probably no more than 20 per hour from Manchester. They are bright, often coloured, medium slow paced meteors which don't usually leave trails. Unlike most other showers these originate from an asteroid, 3200 Phaeton, rather than a comet.   The just past first quarter Moon won't interfere much, this year, setting at 21.57 on 13th and 23.04 on 14th.

Minor showers

Monocerotids:  Nov 27th to Dec 17th, peak 9th, ZHR 3
Weak, medium paced shower. 

Alpha Hydrids:  active 3rd to 15th, peak 12th, ZHR 3
Mostly very faint but the shower does often include some brighter meteors which could be confused with Geminids.

Coma Berenicids  12th to 23rd, peak 16th. ZHR 3
Another weak shower, best seen around 1am when the radiant is high.  These were once thought to be part of the Leo Minorids but are now considered to be a separate shower.

Leo Minorids: Dec 5th to Feb 4th, peak 20th, ZHR 5
A very weak but long lasting shower.

Ursids:  Dec 17th to 26th, peak 21st/22nd, ZHR 5-10 but there are very occasional short outbursts of up to 50.  These medium paced meteors originate from debris left by comet 8P/Tuttle.  The almost full Moon, above the horizon all night, will seriously interfere.

Comets

One (probably - fingers crossed) naked eye comet.

46P/Wirtanen starts the month very low down in Cetus at mag 6.1.  On 1st it culminates at 21.47 but is only 14 degrees above the southern horizon. However it should brighten quite rapidly during the first half of December, unfortunately not reaching the spectacular brightness originally predicted but probably getting to around mag 4.8 between 15th and 19th. It is also moving quickly northwards through Taurus (14th to 18th) Perseus (19th -21st), Auriga (22nd -28th) then into Lynx. On the night of 16th, when it is at perihelion, it passes between the Pleiades and the Hyades (the V shaped head of the bull) and should be quite high in the sky for most of the night.  It is at its closest to Earth on 18th when it passes about 6 degrees to the east of the California nebula (NGC1499).  Sadly, the almost full Moon wll spoil the view on that night. It becomes circumpolar on 21st and  on the night of 23rd/24th passes less than one degree from the bright star Capella.   It fades during the later part of the month, on 31st is predicted to be down to mag 6 but almost overhead - 84 degrees above the northern horizon at 00 25.
Even now, estimates of its brightness vary, some sources say that it will only reach mag 5.5 at its brightest. Even when it is at a theoretical naked eye magnitude it will still be difficult to see without optical aid.  The head and coma are quite large and diffuse, so it will appear as a faint fuzzy blob rather than a star like point of light.

Comet 46p/Wirtanen during December 2018
   

38P/Stephan-Oterma starts the month in Cancer at a mag of around 9.8.  On 1st it reaches its highest point, 65 degrees in the south, at 03.39 and should be visible in a small scope and be an excellent subject for keen astrophotographers. On 12th it moves into Lynx and is slightly higher, 69 degrees at 03.10. It's at its closest to Earth on 17th and on 19th becomes circumpolar, reaching 72 degrees in the south at 02.45.  Towards the end of the month it is caught up by the much faster moving Wirtanen, on 31st they are fairly close with Wirtanen about 30 degrees to the west.

 
There isn't a great deal of information on newly discovered comet C/2018 V1(Machholz-Fujikawa-Iwamoto)- and what I could find often differs.  What all sites agree on is that it is very low in the sky and unlikely to be visible.  Starts the month in Ophiuchus, setting around 18.00 on 1st.  On this day it is very close to the globular cluster M10, mag probably around 9. It moves into Sagittarius on 31st, when it is very close to Pluto - but the pair also appear very close to the Sun, too low in the bright evening sky to be seen, setting only an hour after Sunset.

The night sky in November 2018

posted 31 Oct 2018, 10:39 by Pete Collins

by Anne Holt

Sunrise:   1st    07.07          30th    08.00
Sunset:    1st    16.36          30th    15.54.

New Moon:  7th at 16.01    Full Moon:  23rd at  05.39

Lunar apogee:  14th at 15.55        Lunar perigee:  26th at 12.12

The November full Moon is known as the Beaver Moon, because this is when these animals are active, building their dams in preparation for winter.  Other sources say that it is because this is the time that hunters set beaver traps, before the winter freeze, to ensure a good supply of fur for the cold weather.  Another name for it is the frosty Moon - for obvious reasons.  If it is the last full Moon before the Winter Solstice, which this is, it is also called the Mourning Moon, celebrated by pagans as a time of cleansing and letting go of the past.

Highlights

The main highlight this month is actually the lack of light - at the start we have ten and a half hours of astronomical darkness, rising to almost 12 hours by month end.  And now the clocks have gone back, we have midnight back at its proper time.  After the first few days in November Venus becomes the star of the show for early risers, dominating the pre-dawn sky. There are a few meteor showers and a better than usual chance of fireballs. And the often overlooked constellation of Cetus might be worth a look -  at the end of the month it's home to a comet, a dwarf planet and a 'wonderful' brightening star.

Constellations

If it is clear you will see that the Summer Triangle comprising the 3 bright stars Vega, Deneb and Altair is now sinking slowly in the West, giving way to the stars of winter now rising in the east.

Mid-evening the square of Pegasus, the signature constellation of autumn, is fairly high in the south but not particularly prominent, containing only 2nd magnitude stars. It's an easy star-hop from Alpheratz, the top left star of the square of Pegasus to the Andromeda Galaxy, M31, which is now nicely placed fairly high in the south east.

The Winter Hexagon is a beautifully rich area bounded by Sirius (Canis Major), Rigel (Orion), Aldebaran (Taurus), Capella (Auriga), Pollux (Gemini) and Procyon (Canis Minor).  This relatively small region contains half of the ten brightest stars. It will be above the horizon not long after midnight at the start of November and before 11pm by month end.

The Pleiades, just outside the Hexagon are also very well placed and are a beautiful sight in binoculars or a small telescope.

Cassiopeia is still riding high leaving the Plough, on the opposite side of Polaris, low in the Northern sky for much of the night.

Planets

Mercury:  in Scorpio,  mag -0.2
Very difficult to see throughout the month. On 1st it sets half an hour after the Sun and is on the horizon as the sky begins to darken.  Reaches greatest eastern elongation on 6th, but isn't any higher at dusk. It moves into Ophiuchus on 8th and back into Scorpio on 26th, when it appears only 3 degrees from the Sun.  Reaches inferior conjunction on 27th and crosses the border into Libra on 30th, when it rises at 07.15,  only 45 minutes before the Sun and separated from it by 4 degrees and much fainter at mag 3.8.

Venus:  in Virgo, mag -4.1
Now a morning 'star' but very low in the brightening sky in the first few days of the month. On 1st it rises at 06.37, about half an hour before the Sun, and is on the horizon at dawn.  On 6th it is close to the waning crescent Moon, very low in the east at around 6am.  Its position then improves rapidly and by the second week in November it should be easily visible, on 8th it rises at 05.43 and reaches 8 degrees in the east before the sky brightens a little before 7am.  It will also have brightened to mag -4.4.   By 30th it rises at 04.09, nearly 4 hours before Sunrise, reaching 22 degrees in the south east while the sky is still reasonably dark. It will have brightened to mag -4.7 and be totally unmissable - weather and tall buildings permitting.
Almost worth getting out of bed early for!

Mars:  in Capricorn,  mag -0.6
Still very prominent in the early evening,although it is moving away from us and is therefore fainter, and smaller when seen through a telescope,  To compensate it is now much higher in the sky than it was when at its brightest. On 1st it is 15 degrees above the south eastern horizon as the sky darkens, culminating at an altitude of 19 degrees at 19.01 and setting at 23.30.  It moves into Aquarius on 12th, when it reaches 22 degrees in the south just before 19.00.  The first quarter Moon passes close to the planet on 16th, they should be visible 18 degrees above the south eastern horizon at around 16.30, with the Moon to the left of Mars.  They are actually at their closest, less than 1 degree apart, at 5am on the morning of 16th when they are below our horizon.  By 30th it will have faded to mag -0.1 but will be even higher, reaching 27 degrees in the south at 18.13.  Because the eastward motion of the planet is at the same rate as the apparent westward motion of the stars, it sets at the same time -  23.30 - throughout the month.

Jupiter:  in Libra, mag -1.7
Not visible in November, despite its brightness.  On 1st it is only 2 degrees above the horizon at dusk.  It moves into Scorpio on 21st, when it is 4 degrees from the Sun.  Reaches Solar conjunction, when it is on the opposite side of the Sun to the Earth, on 26th.  On 30th it is a morning object but still not visible, rising 20 minutes before the Sun and separated from it by only 3 degrees.

Saturn:  in Sagittarius, mag 0.6
Should be visible for a short time after Sunset in early November,  from a site with a clear southern horizon.  On 1st it is at an altitude of 11 degrees soon after 17.00 as the sky darkens.  On 11th at the same time it will be less than 1 degree south west of the crescent Moon while the sky is still quite bright. By 30th it will be slightly fainter at mag 0.5 and only 6 degrees above the horizon at dusk.

Uranus:  in Aries, mag 5.7
Still very well placed for binocular observation, or even naked eye under ideal conditions.  On 1st it rises at 16.11 and reaches 21 degrees in the east by 19.00, culminating 47 degrees above the southern horizon at 23.16. On 20th at around 20.00 the gibbous Moon passes 5  degrees south of the planet, however the Lunar glare means that isn't a good time to try to see it.  On 30th it is at 26 degrees in the east as the sky darkens, reaching 47 degrees in the south at 21.18.  As always, a scope is needed to show its blue green disc.

Neptune:  in Aquarius, mag 7.9
Visible in the earlier part of the night during November.  On 1st it is 21 degrees above the south eastern horizon as the sky darkens, reaching 29 degrees in the south by 18.00 and setting just before 2am.  In the early evening of 17th the 70% waning Moon passes it about 6 degrees to the east. By month end it is best seen in the early evening , on 30th it reaches 29 degrees at 18.30, then sinks to 22 degrees by 21.00, setting just before midnight. Not really a binocular object except under ideal conditions and with good binoculars, a scope is necessary for showing a small rich blue disc.

Dwarf planets and asteroids.

Ceres, in Virgo, mag 8.7
The closest of the dwarf planets is still not easy to see this month after October's solar conjunction.On 1st it rises at 05.23 but is separated from the Sun by just 14 degrees.  On 30th it rises over three and a half hours before the Sun but is only 12 degrees above the horizon by dawn.

Possible photographic targets - for experienced amateur astrophotographers.

Eris:  in Cetus mag 18.8
On 1st it culminates at 23.07, 34 degrees above the southern horizon.  By 30th it reaches this altitude at 21.12.

Haumea;  In Bootes, mag 17.4
Ony 12 degrees above the horizon by dawn on 1st.  By mid month it rises soon after 3am and reaches 22 degrees by 06.00.  On 30th it rises at 02.14 and gets to 34 degrees in the east by 06.23.

Makemake:  in Coma Berenices,mag 17.2
Rises at 02.01 on 1st and reaches 28 degrees in the east as the sky begins to brighten.  Its position improves during the month, on 30th it rises at 00.10 and gets to 50 degrees in the south east by dawn.

Pluto:  in Sagittarius, mag 14.7
Not an easy target this month as it never gets higher than 14 degrees above the horizon.

A better bet for those interested in photographing small objects might be:-
Juno, in Eridanus, mag 7.6.
This month is a very good time to try to spot the third asteroid to be discovered, as it reaches opposition on 17th and will be at its closest and brightest for 13 years.  It is very small, only about 3% of the mass of Ceres, but is very reflective and also quite close to us at the moment:  slightly further than the Earth - Sun distance, which explains its current brightness. On 1st it reaches 21 degrees in the south east at 22.11, and 35 degrees in the south by 01.31.  At opposition it will have brightened slightly to mag 7.4, reaching an altitude of 32 degrees at 00.18.  On 30th it will have started to fade again and be at 31 degrees in the south at 23.13.  As with Neptune it might be visible in good binoculars from a dark sky site, unlike Neptune even a fairly large scope won't show it as anything other than a dot, as it is so small.

Recommended websites for more detail on planetary positions at any time:

https://in-the-sky.org    (this site also has lots of other information on planets and all other solar system objects)


Meteor Showers

We have one fairly good shower this month

Leonids:  active Nov 6th to 30th, peak 17/18th  ZHR 10 -20   Parent comet 55P/Tempel-Tuttle.   Although the predicted time of the peak is given as 22.30, the shower is best seen after midnight when the radiant is reasonably high.  This year the Moon sets at 01.22 on the morning of 18th. They are bright, sometimes colourful, fast moving meteors often leaving long trails.

Minor showers

Northern Taurids:  active.Oct 20th to Dec 10th,  ZHR 5,  The peak is given as Nov 10th, when the Moon sets at 18.26, but there is likely to be enhanced activity for about 10 days in early to mid November.  They are bright, slow moving meteors very similar to the Southern Taurids - not surprising as it is thought that they were originally just one shower.  They often include fireballs, so the chance of these is higher in early to mid November when both showers are active.  Parent comet is the predecessor of Encke.

Alpha Monocerotids:  active Nov 17th to December 2nd. ZHR 3 -5.  Peak is given as the early hours of 22nd, when the almost full Moon doesn't set until 06.17 so will seriously interfere.  The radiant is very low in our sky so the actual number of meteors seen is usually fewer than 3.  This shower is best known for its occasional spectacular outbursts.  This year could possibly see slightly higher rates but nothing which could be described as spectacular is predicted.

November Orionids:  active Nov 14th to Dec 6th,  peak Nov 28th, ZHR 3.  Again, the Moon will be in the way, rising at 21.48 on 28th. The radiant of this minor shower is only a few degrees east of that of the Northern Taurids but meteors from the 2 showers should be easily distinguishable as the Orionids are much faster moving.

Comets:

As usual there are several very faint comets around but only a couple brighter than mag 10.

38P/Stephan-Oterma, in Gemini, mag 9.6.  On 1st it rises at 20.41 and culminates, 54 degrees above the southern horizon, at 04.38.  During the month it moves north eastwards below the main stars of Gemini.  On the night of 8/9th it passes only 8 arcminutes from NGC 2392, the Eskimo nebula.  It reaches perihelion on 10th, when it will be marginally brighter at mag 9.5.  It should carry on brightening slowly, predicted to reach 9.3 by 21st, then remain steady for the rest of the month. It crosses the border into Cancer on 30th, when it rises at 18.29, reaching 64 degrees in the south at 03.41.  It's high altitude makes it a good telescopic or photographic target.

46P/Wirtanen,  in Fornax, mag 9,7.  Still too low to be seen from our latitude even though it is now moving northwards. Some sources say that it will reach naked eye visibility in mid November, others think it won't ever get above 6 or 7.  It moves into Cetus on 30th, when it will probably be around mag 7.5, but might just be considerably brighter.  On this night it rises at 18.04 and culminates at 21.49, stll only 13 degrees above the southern horizon, setting at 01.38.

More details of comets are given in the websites mentioned earlier and also www.cometwatch.co.uk

And finally:
Also in Cetus at the end of November, variable star omicron Ceti aka Mira, the Wonderful, reaches naked eye brightness, probably around mag 3.5 but could be as bright as mag 2.  The maxima vary and an exact value cannot be predicted.

The night skyin October 2018

posted 30 Sep 2018, 03:48 by Pete Collins   [ updated 30 Sep 2018, 12:41 ]

by Anne Holt

1st    Sunrise:   07.10      Sunset:  18.45
31st  Sunrise:   07.05      Sunset:  16.38

Astronomical darkness  1st:  20.42 to 05.14    31st:  18.36 to 05.08

New Moon:  9th at 04.46     Full Moon:  24th at 17.45
Lunar perigee:  19th at 22.31,   Lunar apogee: 17th at 19.18

The October full Moon is known as the Hunters' Moon because this was when the deer had fattened up enough that they could be hunted by the light of the autumn Moon, and caught in sufficient numbers to last through the winter.  Other names are the Dying Goose Moon, the Sanguine Moon and the Blood Moon.  This means that if we had a total Lunar eclipse in October it would be a Blood Blood Moon - but this won't happen until 2097. 

Highlights

We have reasonable amounts of astronomical darkness this month, 8 and a half hours on the night of 1st/2nd and 2 hours more on 31st/1st. However it still begins too late for our meetings to get the full benefit - 20.35 on 4th and 19.48 on 25th.   We have a return to Greenwich Mean Time in the early hours of Sunday 28th, when the clocks are put back one hour and we can begin 5 months of proper time.
Mars is still hanging on and the two outer ice giants are very well placed for telescopic observation. We have a few meteor showers, one fairly major, one minor which may turn out to be quite good, and several very minor ones. We also have the probability of some bright colourful fireballs towards the end of the month.

Constellations

The Summer Triangle, made up of Vega in Lyra, Deneb in Cygnus and Altair in Aquila, is losing its dominance in the night sky.  It is still visible during the first part of October high in the south west but by the end of the month all three constellations will have set by 4am. It's place in the southern sky is being taken by the Great Square of Pegasus, autumn's signature constellation.

The beautiful star cluster the Pleiades (also known as the Seven Sisters) followed by the rest of Taurus, will be visible by 11pm in early October and by 8pm (now back to GMT) at month end.

By the end of October Orion will be easily visible by midnight, with Sirius just above the eastern horizon at this time.

Perseus and Andromeda are still high in the sky for most of the night, making it a good time to look for M31, the Andromeda galaxy.   If you are at a very dark sky site, it should be visible to the naked eye, especially when using averted vision.

Cassiopeia is now high in the sky for most of the night, so the Plough, on the opposite side of the North Celestial Pole, is low in the north.

Planets

Mercury: in Virgo, Mag -0.9
An evening object in the first part of October but very difficult to see.  On 1st it sets 15 minutes after the Sun and is separated from it by only 7 degrees.  It moves into Libra on 16th, when it will have faded to mag -0.3 and be 2 degrees below the horizon at dusk. On 31st it sets at 17.05, almost half an hour after Sunset but is barely above the horizon as the sky darkens.

Venus:  in Virgo, mag -4.5
Also below the horizon during the hours of darkness for most of the month.  On 1st it sets just a couple of minutes after the Sun and is 2 degrees below the horizon as the sky begins to darken.  Reaches inferior conjuction on 26th and then becomes a morning object, rising 20 minutes before the Sun on 31st, but still below the horizon when the sky begins to brighten.

Mars:  in Capricorn,  mag -1.3
An evening object in October, a shadow of its June self but still quite prominent.  It fades further during the month but does get slightly higher in the sky.  On 1st it is 9 degrees above the eastern horizon as the daylight fades, culminating (reaching its highest point) 13 degrees in the south at 21.03, setting just before 1am.  The 68% lit Moon passes 3 degrees to the NE at about 19.00 on 18th.  On 31st it will have faded to mag -0.6, culminating at 19.02 at an altitude of 19 degrees in the south and setting at 23.30.

Jupiter:  in Libra,  mag -1.8
May be visible in the early part of the month, low in the west as the sky darkens, setting a few minutes after 20.00 on 1st.  On 11th it is close to the thin crescent Moon.  By month end it is only 3 degrees above the horizon at dusk, setting at 17.26, less than an hour after sunset.

Saturn:  in Sagittarius, mag 0.5
May be seen low in the SW after sunset.  On 1st it is 13 degrees above the horizon as the sky darkens at around 19.30, setting just before 22.30.  On 14th the crescent Moon passes 4.5 degrees west of the planet.  By 31st it will be visible for only a short time, 11 degrees above the southern horizon at 17.20, setting 2 and a quarter hours later.

Uranus:  in Aries,  mag 5.7
Visible for most of the night during October.  On 1st it is 22 degrees above the eastern horizon at 22.00, reaching 47 degrees in the south at 02.27.  It is at opposition on 24th, when it culminates at 00.53 and on the same night the full Moon passes 7 degrees ESE of the planet. On 31st it should be visible around 18.45, when it reaches 21 degrees in the east, culminating at 23.30 and setting at 06.29.  As it is now so well positioned and reasonably bright (for Uranus), it's a good time to try to find it with the naked eye -  if you are observing from a dark sky site.  From the light polluted Manchester sky binoculars, or even a small scope will be necessary.  A larger scope will show the small blue/green disc.

Neptune:  in Aquarius, mag 7.8
The second ice giant is also well placed in October. On 1st it will have reached 21 degrees by 21.00 and culminate at 23.29, at an altitude of 29 degrees above the southern horizon.  By 31st it reaches 21 degrees at around 18.00 and culminates at 20.29, setting at 2am.  As always a scope is needed to show its rich blue colour, though if you happen to have some decent binoculars with you while you're at a dark sky site looking at Uranus, you might just be lucky enough to see Neptune through them.

Minor Planets

With the exception of Ceres, which orbits in the asteroid belt, much closer than the rest, these are very faint and are out of reach of all but the most serious amateur astrophotographers.
Ceres:  in Virgo, mag 8.5 isn't visible for most of the month as it is in conjunction with the Sun on 8th, so too close to it to be seen. On 31st it rises 100 minutes before the Sun but is separated from it by only 14 degrees.

Haumea in Bootes and Makemake in Coma Berenices are also close to Solar conjunction.  Right at the end of October, Makemake at mag 17.1 might be a possible photographic target, reaching 27 degrees above the eastern horizon at around 3am.

Pluto, in Sagittarius, mag 14.7 is also very low, maximum altitude 14 degrees and setting before midnight in early October and at 20.40 on 31st.

Eris, appropriately named after the goddess of strife and discord, is in Cetus, While very faint at mag 18.8 it is in a much better position for astrophotographers.  On 1st it culminates at 02.14 at 34 degrees above the southern horizon.  It's at opposition on 16th, reaching its highest point at 01.15 and on 31st it is in the same position at 23.11.

For more details and exact positions of these at any time, see:

Meteors

One reasonably major shower in October.
Orionids, active October 2nd to November 7th, peak on the night of 21st/22nd, ZHR 20+.  This shower often also has several smaller peaks on the days before and after the maximum. Sometimes a ZHR of up to 50 has been observed,  They are fast moving meteors, often leaving trails.  The parent comet is the best known one of all - 1P/Halley. On the morning of 22nd the almost full moon sets at 04.42 and astro darkness ends at 05.51, giving just over an hour of optimum conditions.

Middling shower
Draconids, aka Giacobinids, active 6th to 10th, peak 9th, ZHR 10.  This shower, like most others is best seen after midnight.  It is said to sometimes show much higher rates when its parent comet, 21P/Giacobini-Zinner, is close to perihelion - as it was in September this year, so you never know!   These are exceptionally slow moving meteors.  New Moon is on 9th, so no interference.

Minor showers.
Camelopardalids:  active 5th to 6th, peak in th early hours of 6th, ZHR 1 - in other words you might be lucky enough to see a couple of meteors.  But maybe not, there hasn't been much activity in the last few years.  However some sources give a ZHR of 5 and say that there could be an outburst on 6th, soon after 3am - just as the Moon is rising.

Southern Taurids:  active late September to early November, peak 10th, ZHR 5.  There may also be minor peaks at any time.  This shower of slow moving meteors is best known for including colourful fireballs.  The crescent Moon sets at 19.28 on 10th.

Northern Taurids:  don't peak until November 12th but can be seen from around 20th October.  These are very similar to the Southern Taurids, it's thought that they were originally one shower which split into 2 streams many thousands of years ago.  As always, poor Jupiter gets the blame when something like this has happened.   The parent comet of both streams is now defunct, it broke into several pieces one of which became Comet Encke.   Several fireballs are often seen in late October when both Taurid showers are active.

Epsilon Geminids: active 14th to 17th, peak 18th, ZHR 3,   Meteors from this shower are often confused with Orionids as they are active around the same time, look similar and have radiants which are not too far apart.  But unless you're a serious meteor observer, I very much doubt that you care!

Leonids Minorids: peak 28th,  ZHR 2

Alpha Aurigids:  active 10th to 18th, peak 11th,  ZHR 2

Comets

21P/Giacobini-Zinner, in Monoceros, mag around 7.6.  The parent comet of October's Draconids is now past its best, heading southwards. On 1st it rises at 01.19 and reaches an altitude of 32 degrees in the south by 04.15. It moves into Canis Major on 11th, passing about 6 degrees east of Sirius on the morning of 13th.  By month end it wll be very difficult to find, down to mag 9.6 and only 8 degrees above the horizon as the sky brightens.

38P/Stepha-Oterma, in Orion, mag 9.7.  Fainter than Giacobini-Zinner but much better placed - and improving.  Starts the month a few degrees north of Betelgeuse, rising soon after 23.30 and reaching 47 degrees in the south while the sky is still dark.  It moves into Gemini on 13th,reaching 50 degrees before dawn.  It then moves N eastwards through the centre of the constellation, on 31st it rises at 20.45 and culminates, 54 degrees above the southern horizon, just before 5am, slightly brighter at mag 9.0.

46P/Wirtanen.  Still very low, and faint at mag 10, but be patient, in November it starts to move north and should have brightened considerably.  On 1st it culminates at 02.20 but only reaches 9 degrees above the horizon, by 31st it's even lower, maximum altitude only 2 degrees, but a little brighter at mag 7.4.
Some sources now say that it will not get as bright as originally predicted but others are still saying that it should be a naked eye object in December, maybe mag 3,  This comet was originally intended to be the target for ESA's Rosetta mission but it wasn't ready in time for the launch window and was sent to Churyumov-Gerasimenko instead.   Pity, it would have made life so much easier for anyone wanting to talk about it.

More comet info can be found in the websites mentioned earlier and also  www.cometwatch.co.uk




The night sky in September 2018

posted 31 Aug 2018, 09:23 by Pete Collins   [ updated 31 Aug 2018, 10:04 ]

by Anne Holt

Sunrise:    1st    06.17        30th   07.08
Sunset:     1st    19.58        30th    18.48

Astronomical darkness:  1st   22.11 to  04.06      30th:   20.45  to  05.12

Autumnal equinox 23rd at 02.54
The closest to 12 hours is two days later -  the 25th is 12 hours 0 minutes and 47 seconds long.

New Moon:  9th at 19.01    Full Moon:  25th at 03.52. 
Lunar perigee 8th,   apogee 20th.
This month's full Moon is known as the Harvest Moon - the one closest to the Autumnal Equinox.  Also known as the Corn Moon or Barley Moon.

Highlights

The nights are getting longer as we approach autumn,  we now have reasonable amounts of astronomical darkness - 6 hours at the start of September and almost 7 and a half hours at the end.  The naked eye planets are becoming less prominent but the two outer ice giants are very well placed for telescopic observation and photography.  The beautiful constellation Orion reappears in the morning sky, on 1st it will be above the horizon by 03.30 and by 01.30 at the end of the month.  We have one binocular and one telescopic comet but no major meteor showers.  The Moon passes through the Hyades, the V shaped asterism in Taurus,  twice this month, on the night of 2nd/3rd and again on 29th/30th.
But, as always in September, the main things we have to look forward to are firmly Earth bound - our Open Day on Sunday 23rd and the start of the new season the following Thursday, 27th.  On this day the Sun sets just 5 minutes before the start of the meeting but astronomical darkness isn't until 20.53, just as we start to pack up.
Never mind!  It'll probably be cloudy anyway.

Constellations

The Milky Way in still prominent overhead, albeit not in these parts! Find a dark sky site though, and it's spectacular.

The Summer Triangle is high in the southern sky for much of the night in early September.  By month end Aquila is setting in the west at about 2am, with Lyra and Cygnus following just before dawn.

However, on the opposite side of the sky, the Pleiades are climbing above the horizon in the east by 10.30pm at the start of September, and as darkness falls at month end. Capella, in Auriga, and the V shaped Hyades cluster at the head of Taurus the Bull are not far behind.

If you stay up until about 4am (or get up very early) you might see Orion making a welcome return to the night sky.  By the end of September, it should be above the horizon by 2am.

The ecliptic is now slightly higher across the Eastern sky, passing through Capricorn, Aquarius and Aries - though none of these are particularly bright or memorable.

Pegasus, Perseus and Andromeda are still well placed, rising in the east to north east from mid evening, as is the bright W asterism of Cassiopeia higher in the north east.

Planets

Mercury:  in Leo, mag -0.8
A morning object in early September, on 1st it rises at 04.32, one and three quarter hours before the Sun, and is 9 degrees above the horizon as the sky begins to brighten soon after 05.30.  Reaches perihelion, the closest point in its orbit to the Sun, on 2nd and on 8th the thin crescent Moon is 9 degrees north west of the planet, low in the east, just before dawn. On 19th it moves into Virgo but can't be seen, despite having brightened to mag -1.7, as it is separated by only 2 degrees from the Sun and rising 15 minutes before it.  It reaches superior conjunction on 21st then becomes a morning object.  However it won't be visible, on 30th it sets at 19.01, only a few minutes after sunset.

Venus:  in Virgo, mag -4.4
On 1st it sets at 20.44 and is only 2 degrees above the horizon at dusk.  It reaches aphelion, its furthest point from the Sun, on 5th.  By 14th it is on the horizon at dusk.  Some sites suggest looking for the planet in daytime, especially towards month end when it is at mag -4.6, but this is not recommended unless you know exactly where to look, as it will be quite close to the Sun.
WARNING: NEVER EVER sweep the sky with binoculars trying to find it.  If the Sun gets in your field of view it is very likely that you would be instantly blinded.

Mars:  in Sagittarius, mag -2.1
Now past its best as it moves away from Earth.  On 1st it culminates at 22.32, 10 degrees above the southern horizon.  It moves into Capricorn on 2nd and on 19th the 75% lit Moon passes 6 degrees north west of the planet, low in the south west just before midnight.  It continues to fade during the month but it does get slightly higher in the sky, on 26th it reaches 13 degrees in the south but is significantly fainter at mag -1.4, no longer outshining Jupiter.  On 30th it culminates at 21.05 and sets just before 01.00.

Jupiter:  in Libra, mag -1.9
On 1st it sets at 21.57, a couple of hours before sunset.  As the sky darkens it is only 10 degrees above the south western horizon.  On 13th the 7% Moon may be seen 6 degrees north west of the planet, just after sunset.  It isn't easily seen in the last week of the month, on 23rd it is only 7 degrees above the horizon when the sky begins to darken.  On 30th it sets at 20.03,  an hour and a half after sunset, before the sky is fully dark.

Saturn: in Sagittarius, mag 0.4
An early evening object this month.  On 1st it culminates at 20.35 as the sky darkens, 13 degrees above the southern horizon.  In the early evening of 17th the 58% lit Moon passes less than 2 degrees north east of the planet. It is fading slightly, mag 0.5 from 20th, but should be easy to spot from a site with a fairly low southern horizon, even in a light polluted area, as it outshines all the stars in Sagittarius.  On 30th it should be visible as the sky darkens, around 19.30, setting at 22.29

Uranus: in Aries, mag 5.7
Currently the highest planet in the night sky, visible for most of the night.  On 1st it rises at 21.15, an hour before the start of astronomical darkness, and reaches 20 degrees in the eastern sky before midnight.  It culminates at 04.28 at 48 degrees above the southern horizon.  On 26th the just past full Moon passes about 6 degrees east of the planet.  On 30th it culminates at 02.31 at an altitude of 47 degrees in the south.  It should be easily visible in decent binoculars, even from the Manchester area.  An amateur scope will show its small pale green disc.

Neptune:  in Aquarius, mag 7.8
Another planet which is well placed in September, though not as high in the sky as Uranus.  On 1st it rises a few minutes after sunset and reaches 24 degrees in the south east before midnight. It culminates at 01.34 at 29 degrees above the southern horizon.  It reaches opposition on 7th, when it culminates at 01.10.  On 23rd, in the early evening, the Moon passes 3.6 degrees south east of the planet.   On 30th it rises around sunset and should be visible before 22.00, 24 degrees in the south east, culminating at 23.34, still reaching a maximum altitude of 29 degrees.  It might possibly be seen in good binoculars from a dark sky site but for most of us a scope will be needed, especially to have a chance of seeing the small blue green disc.  Anyone using a scope of 12 inches or more may be able to spot the planet's largest Moon, Triton, currently at mag 13.4.

Minor planets and Asteroids

Ceres:  in Virgo, mag 8.7
Not a good target this month.  On 1st it sets at 21.16 before the sky is fully dark and is separated by only 20 degrees from the Sun. By month end it's even worse - 8 degrees from the Sun, setting an hour after it.

Minor planets, Pluto in Sagittarius, at mag 14.7 and Eris in Cetus, Haumea in Bootes & Makemake in Coma Berenices, all at mags of around 18 to 19, are too low to be seen in even the best amateur scopes, however could be targets for keen astrophotographers.  Eris is probably the best bet, reaching 34 degrees soon after 4am on 1st and at 2.18 on 30th.  Pluto, Haumea and Makemake are much lower, and getting worse as the month progresses.

Juno: in Taurus, mag 8.8 might be a better bet.  On 1st it rises at 23.03 and reaches 42 degrees in the south east while the sky is still quite dark.  On 30th it will be slightly brighter at mag 8.2, rising at 22.00 and culminating at 04.36.

For more information see
https://in-the-sky.org/ephemeris.php   (minor planets shown under 'asteroids')


Meteor Showers

No major showers this month but we have several minor ones, and September is said to be a good time for sporadic activity.

Alpha Aurigids:  Active August 28th to Sept 5th,  peak on the night of Aug 31st/Sept 1st,  ZHR 6.  This shower sometimes gives a much better display but some years nothing at all is seen.  There are no predictions for a good display this year.  The Moon will interfere but these meteors are very bright so a few may be visible.  Parent comet not known for sure, possibly C1911/Kiess.

Epsilon Perseids.  Active 5th to 21st, peak 9th,  ZHR 5.   Another shower which can produce occasional outbursts.  There was one in 2008 and some sources predict similar this year, on 9th at around 20.00, only 20 minutes after sunset.  Other sources say there won't be any much higher rates until 2040.  These meteors are faint but there is no Moon interference this year.

Piscids:  Low activity for most of September, dates vary according to source used, some say there is no definite peak just enhanced activity between 9th and 21st, others give 2 peaks - Sept 9th, ZHR 5 , and 21st, ZHR 2.  One site gives the very useful information that this shower is 'poorly observed due to lack of observation'. 
Can't argue with that!

Chi Cygnids:  This shower was only officially recognised in 2015 and not much is known about it.  Probable low rates throughout September with a weak maximum on the night of 14th/15th,  ZHR 2-3.  Very slow moving meteors.

Southern Taurids:  Active Sept 10th to November 19th.  The peak is not until October but it's worth looking from mid September as the shower usually includes many fireballs.  These slow moving meteors are thought to originate from a fragment from comet 2P/Encke.


Comets

Most of the current binocular comets are too far south to be seen from our latitude.

One which is high enough in the sky to be seen here is 21P/Giacobini-Zinner, visible for all of September, though it is high in the sky for much longer early in the month.  It starts Sept at mag 7.2, in Auriga, passing 1 degree south of Capella on the night of 2nd/3rd.  Until 8th it is circumpolar but is best seen from just before midnight until dawn, reaching 64 degrees in the north east.  It reaches perihelion on 10th/11th, when it will be at mag 7.1,  or maybe brighter as comets are notoriously unpredictable. It continues its southward path, moving into Gemini on 14th and Monoceros on 23rd. By 30th it will have faded to mag 7.6 (probably) and be best seen in the 90 minutes before dawn when it will be about 30 degrees above the south eastern horizon.

Much fainter comet 46P/Wirtanen is still on course for putting on a good show in December.  At mag 12.6 it is currently only visible in large scopes but is brightening.  At the moment it's low in the sky and getting lower, starting the month in Cetus,  at a maximum altitude of 17 degrees.  It moves into Fornax on 22nd and should have brightened to around mag 10 and  have a maximum height of 12 degrees.  On 30th it will be even lower, no higher than 10 degrees.
But be patient!   From early November its position, and hopefully its magnitude, will improve.

For more details on comet positions see www.cometwatch.co.uk.  Information is also given in the websites mentioned earlier.

The night sky in August 2018

posted 29 Jul 2018, 14:31 by Pete Collins

by Anne Holt

Sunrise        1st:   05.24         31st:   06.16
Sunset         1st:   21.05         31st:   20.01

Astronomical darkness
1st:  00.38  to  02.02         31st:  22.14 to 04.04

New Moon:   11th  at 10.57
Full Moon:    26th  at 15.26

Lunar perigee:  10th at 19.06
Lunar apogee:   23rd at 12.25

August's full Moon is known as the Sturgeon Moon because these fish in the American Great Lakes are said to be easiest to catch at this time. Other names are the Green Corn Moon and the Grain Moon.  Some North Americans call it the Red Moon as it sometimes appears this colour when it rises through the summer haze.

Highlights

Nights are getting longer by almost 4 minutes each day and we have increasing amounts of astronomical darkness during August - 2 and three quarter hours on 1st and nearly 6 hours on the night of 31st August/1st Sept. 
The new Moon on 11th is a Supermoon, occurring close to Lunar perigee.  Of course a new Moon can't be seen but the thin waning crescents, rising at 02.55 on the morning of 9th and at 04.05 on the 10th,  should appear larger than usual.
There is a small partial eclipse on the morning of 11th but it is only visible from the far north of Scotland,  Orkney, Fair Isle and Shetland.  From Thurso on the coast of northern Scotland, the edge of the Moon will cross the face of the Sun between 09.30 and 10.00.  From Lerwick, in Shetland, the eclipse will be slightly longer - 09.30 to 10.15.  However, it will be a very small 'bite' out of the Sun  the maximimum is only 2.5% when seen from the most northerly part of the Shetland Isles.
And, of course, we have the year's best meteor shower, the Perseids, free this year from Moon interference.

Constellations

When it finally gets dark enough, the Milky Way is now at its best.  From a dark sky site it can be seen stretching right across the sky and down to the southern horizon, passing almost overhead around midnight.

The Milky Way passes through the Summer Triangle, which is now high in the sky, with Deneb and Vega particularly prominent.  Alberio, a beautiful yellow and blue double star at the head of Cygnus the swan, is very well placed for telescopic observation.

The Plough and its host constellation Ursa Major are now very low in the Northern sky which means that the W asterism of Cassiopeia is riding high in the south east and very easy to spot.

Pegasus and Andromeda are now well above the horizon for most of the night and Perseus, followed by Auriga, are rising soon after midnight.

Planets

Mercury:  in Libra, mag 2.9. Not visible for most of August.  On 1st it sets a few minutes before the Sun and is separated from it by only 14 degrees.  The angular distance decreases as it approaches inferior conjunction on 9th.  It then becomes a morning object, in Cancer, but is still too low to be seen until the last few days of the month. On 20th it will be at mag 1.4 and be a few degrees above the horizon at 05.15.  On 26th it reaches greatest western elongation, 18.3 degrees from the Sun but still only 8 degrees above the horizon at dawn - though brighter at mag - 0.1.  On 30th it moves into Leo and on 31st it rises at 04.25,  reaching 8 degrees above the eastern horizon at 05.46, half an hour before sunrise, and brighter at mag -0.7.

Venus:  in Leo, mag -4.2. Could be seen in early August, on 1st it sets at 22.22, about 90 minutes after sunset.  It is only 7 degrees above the horizon at dusk but should be visible, given an unobstructed view,  as it is so bright.  It moves into Virgo on 2nd.  The angle of the ecliptic is decreasing so the planet is getting lower in the sky, even though it reaches greatest eastern elongation on 17th.  On this day it is 49.5 degrees from the Sun but only 4 degrees above the western horizon at dusk, setting about an hour after sunset.   On 31st it will have brightened to mag -4.4 but will be only 3 degrees above the horizon as the sky begins to darken, setting about 45 minutes after the Sun.

Mars:  in Capricorn, mag -2.8. Still very bright, and large when seen through a scope, but rather low in the sky.  On 1st it culminates at 00.57, only 10 degrees above the southern horizon.  In the first few days of August it's disc is 24 arcseconds in diameter, however it will be difficult to see, or image, much detail through a scope - not only is it low but there are currently huge dust storms blowing across the surface.  It fades slightly during the month, on 23rd, when the 82% lit Moon passes 6 degrees to the north, Mars will be at mag -2.3.  Its apparent motion is retrograde for most of the month but after 28th it resumes prograde, or direct, motion appearing to move eastwards against the background stars. On 31st it culminates at 22.36, 10 degrees above the southern horizon  It sets at  01.59 and will have faded to mag -2.1.

Jupiter:  in Libra,  mag -2.1. Quite low in the west as the sky darkens now. On 1st it is only 15 degrees above the horizon at 21.30, setting at 23.35. On 17th the 45% lit Moon passes about 5 degrees north of the planet. By month end it will have faded slightly to mag -2.0, be only 11 degrees in the SW a few minutes before 20.30 as the sky darkens, and set at 22.00.

Saturn:  in Sagittarius, mag 0.2. An early evening object, not easily seen as it is currently sitting north of the teapot asterism, where the Milky Way is rather bright.  It is also quite low - on 1st it is only 12 degrees above the southern horizon as the sky darkens, just before 22.00. It culminates, a degree higher, at 22.41 and sets at 02.33.  On 31st it culminates only half an hour after sunset and may be seen, 13 degrees above the southern horizon, just before 21.00.  It sets at 00.30 and will have faded to mag 0.4. 

Uranus:  in Aries, mag 5.8. On 1st it rises at 23.17 and reaches 33 degrees in the SE before the sky begins to brighten.  It is currently the only planet reaching a good altitude.  On 4th it is about 4 degrees north of the third quarter Moon.  It gets even better as the month progresses and on 31st it culminates at 04.32, 48 degrees above the southern horizon, it will also be marginally brighter at mag 5.7.  Because it is so well positioned, high in the sky at the moment, it could possibly be seen with the naked eye from a dark sky site - with the usual proviso that they eye in question must have 20/20 vision and know exactly where to look.  Though I've yet to meet anyone who has seen it without any optical aid.  It should be an easy binocular target, and a decent amateur scope will show a small blue/green disc. A much larger scope will be needed to show any markings.

Neptune:  in Aquarius, mag 7.8. Reasonably high in the sky, though lower than Uranus.  On 1st it rises at 22.07 and reaches 29 degrees in the SE before the sky begins to brighten.  On 27th the just past full Moon passes about 6 degrees to the SE just before midnight.  By month end the planet culminates at 01.38, 29 degrees above the southern horizon.  It could possibly be seen, through decent binoculars, in the late evening in the second part of the month - though probably not from Manchester.  A good amateur scope should show its bright blue disc.

Minor planets

Ceres and Pluto are too low to be easily spotted this month.

Eris, Haumea and Makemake are possible targets for keen amateur photographers with good equipment.

Eris:  in Cetus, mag 18.8. On 1st it rises at 02.22 and is 23 degrees above the horizon at dawn.  Its position improves during the month, on 31st it rises at 22.21 and culminates at 04.17,  34 degrees above the southern horizon.

Haumea:  in Bootes, mag 17.4. Starts the month 27 degrees above the western horizon as the sky darkens, setting at 02.21.  By 31st it is 23 degrees above the horizon at dusk, setting not long after midnight.

Makemake:  in Coma Berenices,  mag 17.2. Setting about 15 minutes before Haumea throughout August, but lower in the sky - 22 degrees just before dawn on 1st, 18 degrees on 31st.

For more information, including exact positions on any day see:
https://in-the-sky.org/ephemeris.php      (for minor planets, look under asteroids)

Meteor Showers

One (very) major shower, this month.

The Perseids, active July 13th to August 26th.  Peak on the night of 12th/13th but good rates can usually be seen a day or so either side of this.  ZHR at peak is given as 100 but this is under ideal conditions - from a dark sky site with the radiant directly overhead.  Usual rates under dark skies more likely to be in the region of 50 to 75, and as low as 10 from a light polluted urban area.  Best seen after midnight (01.00 BST) when the radiant is high in the sky,  but it is worth looking earlier as the shower sometimes includes Earth grazers - rare, slow moving meteors streaking across the horizon leaving bright persistent trails, which are occasionally seen when the radiant is very low in the sky.  The Perseids happen when Earth passes through debris left by comet 109P/Swift Tuttle.  This year the Moon is out of the way, it sets at 21.32 on 12th. All we need is for clouds to stay out of the way, as well.

Minor Showers

Kappa Cygnids.  active 3rd to 25th, peak 18th.  However, this shower may have altered and be active between 6th and 18th with a peak on 14th.  ZHR 5, but sometimes many more.  According to the IMO this shower does not always behave as it is supposed to.  They are slow moving, often very bright, meteors, parent comet unknown.  The Moon sets before midnight on both the possible peak dates.

Aurigids,  active August 28th to Sept 5th, peak 31st/Sept 1st.  ZHR 6, again sometimes more, but not predicted for this year.  These are bright, slow moving meteors.  80% Moon rises at 22.13, so will interfere.

There are a couple of showers whose peak is actually at the end of July, but which usually have reasonable rates for a couple of days after, so might be worth looking on the first couple of days of August.

Alpha Capricornids:  active to August 15th, ZHR 5.  Slow moving, yellow tinged meteors often leaving trails.  Moon rises soon after 23.00 on 1st, but the shower often includes fireballs which may be visible despite this.

Southern Delta Aquariids,  active to August 15th.  medium paced, faint meteors. so more likely to be washed out by moonlight.

Comets

In August we have a couple of comets which may be visible in binoculars.

21P/Giacobini-Zinner.
Currently circumpolar.  Starts the month at about mag 9 (sources vary - there's a surprise) moving from Cassiopeia into Draco.  Back into Cassiopeia mid month before moving through Camelopardalis and ending the month in Auriga, heading towards Capella, when it is predicted to reach mag 7.2.  Or maybe even brighter.

PanSTARRS (2017S3)
Visible in the morning sky in the first few days of August. Starts the month in Auriga, then quickly moves into Gemini and getting too low to be seen before dawn. The magnitude increased rapidly during July, from 12 to 9.  Starts August at mag 8 and could brighten to 7.

comet positions also given in in-the-sky.org


The night sky in July 2018

posted 29 Jun 2018, 13:50 by Pete Collins   [ updated 30 Jun 2018, 04:58 ]

by Anne Holt

Sunrise     1st:   04.44        31st:  05.22

Sunset      1st:   21.40        31st:  21.06

Astronomical Darkness    1st:  none     31st:  00.50  to  01.40

The Earth is at its furthest from the Sun (aphelion) on 6th at 17.46

New Moon:   13th  at  03.47

Full Moon:     27th at  21.20.

July's full Moon is known as the Buck Moon because it's when new antlers start to grow.  Other names are Thunder Moon, Wort Moon or Hay Moon (Old English).

Lunar Perigee (closest to Earth)  13th

Lunar Apogee (furthest from Earth)  27th

Highlights

At last we have some real highlights to look forward to. The nights are now beginning to get longer, though not yet by much - sunset is less than a minute earlier each night in early July, rising to a couple of minutes by month end. On 31st we have a return of astronomical darkness, when the Sun will be more than 18 degrees below the horizon for a whole 50 minutes.  The new Moon on 13th is a supermoon, of course it can't be seen but the thin crescent just before and after this should appear larger than usual. There is still a chance of seeing noctilucent clouds shortly before sunrise or after sunset, especially in the first part of the month - see June notes for more details about these.  And, at the end of the month, we might see some fireballs.

The real highlights are Mars at opposition on 27th, towards the end of July it will be at its biggest and brightest for 15 years, and a total lunar eclipse on the same evening (details at the end of this post).  Unfortunately these will be very low in the sky but should be visible from a site with an unobstructed, unpolluted SE horizon - and a clear sky!

Constellations

The Summer Triangle (made up of Vega in Lyra, Deneb in Cygnus and Altair in Aquila) is now quite high in the southern half of the sky. Cygnus, with its Northern Cross asterism, and Lyra are particularly prominent.

At the start of the month Pegasus, followed by Andromeda, is rising in the early hours.

As always during the summer months, it isn't the best time to see the zodiac constellations or planets as the ecliptic never gets very high in the sky.  However, if you do happen to visit a dark sky site over the next few months you should be rewarded with good views of the Milky Way high overhead running through Cygnus and down to Sagittarius just above the southern horizon.

Planets

Mercury:  in Cancer,  mag -0.1. Might be spotted very low in the west soon after sunset at the start of the month.  On 1st it sets at 23.00, about 80 minutes after the Sun, but is only 3 degrees above the horizon at dusk so isn't an easy target.  It reaches greatest eastern elongation on 12th, when it sets at 22.33 and is separated by 26.4 degrees from the Sun. Because of the decreasing angle of the ecliptic to the horizon it is even lower in the sky - on the horizon as it begins to get dark.  It will also have faded to mag 0.4. On 14th it is about 2 degrees South of the 4% Moon soon after sunset.  It moves into Leo on 15th, then can't be seen for the rest of the month.  On 31st it sets about the same time as the Sun and will have faded to mag 2.6. 

Venus:  in Leo, mag -4.1. Still very bright but much lower in the evening sky.  On 1st it sets at 23.40 and is 12 degrees above the horizon at around 22.00 as the sky begins to darken.  Unlike Mercury it can easily be seen while the sky is still bright.  On 9th, when it sets a couple of hours after the Sun, it is close to Regulus (alpha Leonis).   On 15th the 10% Moon passes just over 4 degrees North of the planet.  By 31st it sets at 22.25, 80 minutes after sunset and is only 7 degrees above the horizon at dusk, but is slightly brighter at mag -4.2.

Mars:  in Capricorn,  mag -2.2. Mars is the star of the show in the second part of the month.  On 1st it rises at 23.35 and culminates (reaches its highest point in the sky) 13 degrees above the southern horizon at 03.33 - 80 minutes before sunrise.  On this night it will be about 5 degrees south of the 91% lit Moon, soon after midnight.  During the month the planet brightens considerably as it approaches perihelion (the closest point in its orbit to the Sun). The last week in July it reaches mag -2.8,  brighter than Jupiter at its best.  It will also appear much larger when seen through a telescope, apparent diameter 21 arcseconds on 1st, increasing to 24.3 arcseconds by 31st.  This is only slightly smaller than the maximum possible. At its furthest from us the diameter is only 3.5 arcseconds.  The big difference in size, compared to the outer gas giants, is because we are so much closer to Mars.  At its closest it is only about 35 million miles, at its most distant 250 million miles - more than 7 times further.  By comparison, Jupiter at approx 365 million miles and 601 million miles is just over 1.6 times further at its most distant, so the difference in brightness and size is much less marked.

 Mars reaches opposition on 27th, when it rises at 21.53 and culminates at 01.22.  This is known as a perihelic opposition because it occurs when the planet is only a few days from perihelion.  However, because it's apparent motion is currently retrograde (east to west against the background stars) and because the angle of the ecliptic is decreasing, it will be slightly lower in the sky - only 10 degrees - than in early July. It reaches perihelion on 31st, when it will be at its closest to Earth for 15 years -  and the 2003 opposition was the closest since Sept 24th 57,617BC.  Please don't ask whether this is according to the Julian or Gregorian calendar,  I haven't  a clue!  The next time it will be as close is August 28th 2287. It is best seen after 23.20 when it reaches an altitude of 7 degrees.  It culminates at 01.02, 10 degrees above the southern horizon.

A word of warning:  If the old chestnut appears on the internet about Mars being as large as the Moon in the sky, don't believe a word of it.  The Moon will be 75 times larger, Mars will still appear as a point of light to the naked eye - albeit a very bright orange-red point of light.

Jupiter:  in Libra.  mag -2.3. An early evening object now, best seen in the first part of the month.  On 1st it culminates at 21.14, just before sunset and sets at 01.58.  Best seen after 22.00, when it will be 20 degrees above the SW horizon as the sky darkens.  On 10th it resumes direct, or prograde, motion appearing to move eastwards across the sky.  By 14th it will have faded slightly to mag -2.2 and will be outshone by Mars, now at -2.5. On 31st it is down to mag -2.1 and sets at 23.57. As the sky darkens it will be 15 degrees above the SW horizon.

Saturn: in Sagittarius, mag 0.00. An evening object, still very low in the sky.  On 1st it culminates at 00.56, 13 degrees above the southern horizon, and sets around sunrise.  On 24th it is 2 degrees (or maybe 4 degrees depending on who you believe) SE of the 92% lit Moon at around midnight. By month end it will have faded slightly to mag 0.2, reaching its highest point at 22.45, before the sky is fully dark, and setting at 02.37.

Uranus:  in Aries*, mag 5.9. On 1st it rises at 01.22 but only reaches 1 degree above the horizon by dawn.  May be seen in the later part of the month, on 20th it will be 22 degrees above the eastern horizon at 02.40.  On 31st it rises at 23.21 and reaches 32 degrees in the SE before the sky brightens.  Unlikely to be visible to the naked eye - decent binoculars or a small scope are needed.  A larger scope will show the blue/green disc. * Apologies: last month I said that Uranus was in Pisces, despite it having moved into Aries at the end of April (habit, didn't even look - it was in Pisces for longer than I've been doing these notes.)  Did anyone notice, I wonder?

Neptune:  in Aquarius, mag 7.9. On 1st it rises at 00.13 and reaches 11 degrees above the horizon by dawn.  On 4th the 68% lit Moon passes 3 degrees south of the planet.  On 18th it reaches 25 degrees in the south by 02.35.  On 31st it is 4 degrees north of the 89% Moon, rising at 22.11 and reaching 29 degrees as the sky brightens.  Should be visible as a bright blue disc in a reasonable sized amateur scope.


Dwarf planets and asteroids

Still not a good time for spotting or imaging these faint objects because they are mainly very low in the sky - which, of course isn't completely dark for almost the whole of July.

Pluto: in Sagittarius, mag 14.8. Very low in the sky throughout the month, never getting higher than 14 degrees above the horizon.  On 1st it culminates at 01.59.  Reaches opposition on 12th, 2 days before the 3rd anniversary of New Horizons' historic flyby.  On this day it culminates at 01.15 and at 23.34 0n 31st.

Haumea: in Bootes, mag 7.4 and Makemake, in Coma Berenices, mag 17.1 are possible targets for keen astrophotographers, especially in the first part of the month.  On 1st Haumea reaches an altitude of 31 degrees, and Makemake 27 degrees.

Asteroid Vesta: in Ophiuchus, mag 5.6. Fading during July.  In the first few days of the month it is a naked eye object in theory, though very unlikely in practice, even from a dark sky site, as it is very low in the sky. On 1st it culminates at 00.15, only 15 degrees above the southern horizon.  On 31st it sets at 01.47 and will have faded to mag 6.8.

NOTE: one astro mag says that on 12th it will appear only 0.3 degrees from the Moon.  I couldn't find mention of this anywhere else so I checked the positions.  On this day Vesta is in Ophiuchus and the Moon is passing through Orion and doesn't rise until after Vesta has set.  More like 180 degrees apart.

Ceres and Eris not visible this month.

Recommended sites for more details on planetary positions:

https://in-the-sky.org/ephemeris.php

https://theskylive.com

www.nakedeyeplanets.com

Meteor Showers

 One middling and a couple of minor showers, this month.

Delta Aquarids, active July 12th to August 23rd, peak on the night of 29/30th. ZHR 16, though probably significantly fewer from our northern latitude.  Only a few days past full Moon, so that won't help either.. Medium paced meteors,  parent comet 96P/Macholz. .

Alpha Capricornids,  active July 3rd to August 15th, a fairly long peak around 30th, ZHR  5.  These are slow moving meteors, the shower usually includes fireballs. Parent comet 169P NEAT.  Again, the Moon will interfere and the low radiant means that the shower is better seen from further south.

These two showers both have radiants on the ecliptic so could be confused with meteors from the Antihelion Source, which is active in late July (ZHR 2 -3).  These are faster paced than meteors from either of the showers so should be distinguishable.

There could be a few visible meteors from the Gamma Draconids. An outburst of 100 was observed 1n 2016 and we could have a similar number this year.  But don't get too excited -  this year the peak is predicted around midday on 28th, so will only be detectable using radio or radar equipment.

Sporadic activity is usually good in July and we may see some early Perseids in the second half of the month.

Comets

Still no bright, or even fairly bright, comets.  The best one Pan/STARRS(2016M1) at mag 9 is now only visible from the southern hemisphere. From our latitude we have 21P Giacobini-Zinner, currently at mag 13 or 14 (guess what? As usual, sources fail to agree) in Cygnus, moving towards Cassiopeia and expected to brighten considerably over the next couple of months, maybe even becoming a naked eye object from late August.

see www.cometwatch.co.uk/current-observable-comets/  for more detail.

And finally, leaving the best until last ...

On July 27th we have a total lunar eclipse or, to be precise, half an eclipse, as the Moon will be fully in shadow as it rises at 21.07,  47 minutes after the start of totality. At 21.21, the mid point of the eclipse, the Moon will be only 1.4 degrees above the horizon.  By the time totality ends, at 22.13, it will have reached an altitude of 6.8 degrees and be almost directly SE.  The partial phase finishes at 23.19, with the Moon at an altitude of 12.4 degrees.

The very low altitude during totality means that in order to see this event you will need to be somewhere with a a clear SE horizon with no light, or other, pollution to spoil the view.  The Moon will appear very small in the sky,  known as a Micromoon as it is close to apogee (furthest point from Earth). This does mean that it will be moving more slowly than when it is closer to us.  Also at this time the Earth is only 3 weeks past aphelion, when the umbral shadow is at its widest and longest of the year.  These, combined with the fact that the Moon will pass through the shadow very close to the centre - the widest point - mean that this eclipse will be the longest of the 21st century. With 1 hr 43 minutes of totality it is only 4 minutes short of the maximum possible.  The eclipse of July 16th 2000 (which counts as the 20th century) was slightly longer, at 1 hr 46.4 minutes.

 As you may have realised, this eclipse is on the same night that Mars reaches opposition.  However, Mars rises at 21.53, only 20 minutes before the end of totality, so it is very unlikely that both will be visible at the same time.   The partial phase of the eclipse ends at 23.19 so it might be possible to see Mars and a partial eclipse together - given the right conditions.

And, on that night there's a chance of some fireballs, though they will be in the opposite part of the sky so everyone will probably miss them.

The bad news is that, statistically, we only have a 13% chance of clear skies.

The night sky in June 2018

posted 31 May 2018, 12:13 by Pete Collins   [ updated 29 Jun 2018, 13:21 ]

by Anne Holt

Sunrise      1st:  04.47        30th:   04.43
Sunset       1st:  21.27        30th:   21.41

Earliest sunrise  17th at 04.39.    Latest sunset 24th at 21.42 
The Summer Solstice, when the Sun reaches its highest point in the sky, is on Thursday 21st at 11.07.  This is also the longest day - 9hrs 33 minutes longer than at the Winter Solstice.

Astronomical darkness:  none

New Moon:  13th at 20.43     Full Moon:  28th at 05.53
June's full Moon is known as the Strawberry Moon, because it's the time when wild strawberries begin to ripen.   Alternative names are the Rose Moon or Mead Moon.
The Moon is at perigee  (closest point in its orbit to Earth) on 15th, and at apogee (furthest point) on 2nd and again on 30th. 

Highlights

We still have far too much light this month.  Not only do we have no astronomical darkness in June, we have very little astronomical twilight, when the sun is between 12 and 18 degrees below the horizon - about 3 hours in early June, falling to 2 for the second half of the month.  Saturn is at opposition on 27th, so at its best for the year, though still very low in the sky.  Mars is brightening rapidly but Jupiter is now beginning to fade, and sets soon after 2am by month end.  And, of course, Venus is still dominating the sky in the west after sunset, setting around midnight throughout the month.  Finally, we are now in the season for noctilucent clouds.  These blue tinged, wispy clouds may be see low in the NE 90 mins to 2 hours before Sunrise, and in the NW a similar time after Sunset.  They are made up of ice crystals about 50 miles up - so high that they catch the light of the Sun while it is below the horizon.

Constellations

The Plough asterism in Ursa Major is still prominent, being overhead for much of the night, leaving Cassiopeia on the opposite side of the Pole Star, low in the northern sky. The Summer Triangle, consisting of Vega, Deneb and Altair, is now getting higher in the late evening, though Altair, in Aquila, is still quite low in the early part of the night.  The beautiful double star Albireo, at the head of Cygnus the swan, is very well placed for observing. The Milky Way is now visible from dark sky sites, running across the sky through the Summer Triangle, passing almost overhead in the early hours. The bright orange red Arcturus is shining brightly high in the SW and, if you manage to find some dark skies not obscured by cloud, you should be able to see the rest of the kite shaped Bootes, with the semicircle of stars forming Corona Borealis just to the east of it. Another red giant, Antares in Scorpio is now visible low on the southern horizon.

Planets

Mercury:  in Taurus, mag -1.7. Not easily seen this month.  On 1st it rises only 19 minutes before the Sun, when the sky is too bright for it to be visible.  It reaches Superior Conjunction, when it is on the far side of its orbit from the Earth, on 5th, after which it becomes an evening object.  It moves into Gemini on 14th but is still not visible, despite having brightened to mag -2.4, as it is only 2 degrees above the Western horizon at dusk. It then moves into Cancer on 28th and on 30th it sets 81 minutes after Sunset, at 23.02.  It will have faded to mag -0.3 and still be too low to be seen:  only 3 degrees above the horizon as the sky begins to darken.

Venus:  in Gemini,  mag -4.0. Still shining very brightly in the late evening Western sky.  On 1st it sets at 00.15 and is 16 degrees above the horizon as the sky darkens around 22.00. On 10th and 11th it will form a line with Castor and Pollux, very low in the NW as the sky begins to darken, with Venus the lowest and about 100 times brighter than the twins.  Try looking a few minutes either side of 23.00, when the sky will be in nautical twilight and the brightest stars can be seen. The trio should be visible from a dark sky site with a low NW horizon - provided that there's no skyglow from nearby towns spoiling the view.  Venus moves into Cancer on 13th, when it will be 15 degrees above the horizon at 22.00, and on 16th the 3 day old Moon passes a little over 2 degrees South of Venus.  They are at their closest at 14.13 but should still be close enough to be in the same binocular field of view, 14 degrees above the horizon, at around 22.15. It moves into Leo on 30th, when it sets at 23.42.  It will be slightly lower in the sky, 12 degrees at 22.10, but slightly brighter at mag -4.1.

Mars: in Capricorn mag -1.2. On 1st it rises at 01.10 and reaches 13 degrees in the South as dawn begins to break.  It brightens rapidly during the month and also appears to be getting larger as it gets closer to us. From 28th it appears to change direction and move Westwards against the background stars.  This is known as retrograde motion and occurs when Earth overtakes an outer planet, in the same way that a moving vehicle may appear to be going backwards to people in a car overtaking it. By 30th it rises at 23.37 and reaches its highest point, 13 degrees in the South, at 03.27.  It will then be at mag -2.1, almost as bright as Jupiter - and much more colourful to the naked eye.  However it is still below the celestial equator, so much better seen from further South.

Jupiter:  in Libra,  mag -2.5. Now past its best for this year.  On 1st it reaches its highest point, 21 degrees above the Southern horizon, at 23.30 and sets at 04.20, just under half an hour before Sunrise.  Like Mars it is now retrograde, but unlike Mars it is now beginning to fade.  On 30th it culminates 20 minutes before Sunset and should be visible 20 degrees above the Southern horizon at around 22.00, before setting at 02.02   By this time it will have faded slightly to mag -2.3.   

Saturn:  in Sagittarius, mag 0.2. On 1st it rises at 23.10 and culminates at 03.03, 14 degrees above the Southern horizon.  Also on this day it will be slightly less than 1 degree South of the 94% lit Moon soon after midnight.  It reaches opposition on 27th, still very low in the sky, only 14 degrees at 01.13 when it is at its highest.  However it is well worth seeing through a scope, especially from a site with a low, clear, unpolluted Southern horizon, as the rings will be a spectacular sight for a few days either side of opposition.  They appear much brighter because of something known as the Seeliger effect: when the Sun shines directly on to the rings the shadows cast by the individual component particles are directly behind them and can't be seen, rather than being seen to the side, thus dimming the rings.  Also they are currently wide open, angled at 26 degrees to the line of sight.  The bad news is that, because Saturn moves so slowly across the sky, the next few oppositions will also be when the planet is very low.  It is improving, though, in 2022 it will be at 20 degrees, almost as high as Jupiter is now.  It then gets better quite quickly and in 2028 will be in Aries, highest point 49 degrees - so be patient. The full Moon passes close to the planet near the end of the month, about 1 degree to the North on the night of 27/28th.  On 30th it culminates at 01.00 and sets at 04.49, a few minutes after Sunrise.

Uranus:  in Pisces, mag 5.9. Very difficult to see this month.  On 1st it rises at 03.18, about 90 minutes before the Sun, but the sky will be too light for it to be seen.  Rises at 01.26 on 30th, 3hrs 17 minutes before Sunrise, as the sky begins to brighten, so won't be visible to the naked eye, even under ideal conditions.  Might be spotted, very low down, with binoculars or a scope from a site with a good Eastern horizon but be very careful - keep an eye on the time and stop well before Sunrise.

Neptune:  in Aquarius,  mag 7.9. On 1st it rises at 02.11 but the sky is beginning to brighten at this time.  On 30th it rises 4hrs 26 minutes before the Sun, while the sky is quite dark - or as dark as it gets at this time of year - but will only reach an altitude of 9 degrees in the South as the sky brightens.   As before, take great care when using scopes before sunrise.

June isn't a very good time for trying to spot, or image, dwarf planets because they are mostly very faint and the sky never gets properly dark.

Haumea, in Bootes at mag 17.4 might be a reasonable imaging target, especially in the early part of the month, when it will be about 50 degrees above the SW horizon around midnight.

Makemake, in Coma Berenices mag 17.0 could possibly be found in early and late June.  On 1st it is 50 degrees above the SW horizon around midnight.  This falls to 27 degrees by 01.00 on 18th, then it becomes very hard to find as the sky is too bright.  Might be visible for a few minutes during the last few days, about 26 degrees in the West, around 1am.

Pluto, Eris and Ceres are all very low and very difficult to find in the less than perfect darkness.

Asteroid Vesta reaches opposition on 19th, in Sagittarius.  At mag 5.3 it is theoretically a naked eye object from a dark sky site but, in practice, is unlikely to be visible as it is very low in the sky - about 15 degrees at its highest.  And, if that wasn't enough, it is currently in an area of the sky where the Milky Way is rather bright.

For more information on the exact positions of planets, dwarf planets etc, see
Dwarf planets are shown under 'asteroids'.
Another useful site is https://theskylive.com


Meteor Showers

No major showers this month, and not much in the way of minor ones either.

June Lyrids, peak 15/16th.  A ZHR of 8 -10 has been reported in the past but there has been no activity in recent years.

June Bootids:  June 22nd to July 2nd, peak 22nd, ZHR variable - has occasionally been as high as 100 but, again, is often zero. The orbit of the parent comet 7P Pons/Winnecke has altered and does not now come as close to Earth as it did in the past. We only get a good display when we pass through a dust cloud on the former orbit.

The antihelion source is active in early and late June though the radiant is very low, in Sagittarius, so they are better seen from further South.

There are several daytime showers in April. These can only be detected using radar or radio telescopes and were first discovered in 1947 by a team including Prof (later Sir) Bernard Lovell, who were studying cosmic rays.   Among these are the daytime Arietids which peak on June 7th, ZHR up to 30.  A few meteors have been observed visually just before dawn around the peak.

Comets

Still nothing brighter than mag 10.   PanSTARRS (2016M1), currently mag 10 and 48P/Johnson, currently mag 13, are said to be brightening - though probably not by much.

Giacobini-Zinner, in Cygnus, reaches perihelion in June.  Now mag 15 but is expected to brighten over the next few months, maybe reaching mag 6.

The night sky in May 2018

posted 28 Apr 2018, 04:56 by Pete Collins   [ updated 28 Apr 2018, 05:40 ]

by Anne Holt

Sunrise:      1st    05.34           31st   04.47
Sunset:       1st    20.38           31st   21.26

Astronomical darkness: 1st   23.26  to  02.45           31st     none
On 13th it begins at 00.39 and ends at 01.30 - and that's it until the end of August.  Though in our light polluted sky we're unlikely to notice much difference.

New Moon:  15th at 12.47
Full Moon:    30th at 01.58
This is known as the Flower Moon, for reasons which will be obvious to gardeners and Gilbert and Sullivan fans.

Highlights

Venus and Jupiter are both unmissable at the moment and Mars and Saturn are brightening slightly, though still very low in the sky.  We have one major meteor shower, marred by the presence of the gibbous Moon, and a small amount of astronomical darkness in the first half of the month.  Late May sees the start of the Noctilucent Cloud season. These are fine, wispy, blue tinged clouds so high in the atmosphere that they catch the sunlight before sunrise and after sunset.  They might be seen, low in the NE , 2 hours to 90 minutes before sunrise and in the NW 90 minutes to 2 hours after sunset.  Bright passes of the ISS are well after midnight for most of the month, and then late evening towards the end of the month. And we might see an end to all these April showers.  Fingers crossed that they aren't replaced by May showers!

Constellations

As the sky darkens at the start of the month Lyra and Cygnus are rising in the north east, followed a couple of hours later by Aquila.  In the later part of the night the Summer Triangle formed by Vega, Deneb and Altair, the brightest star in each of these three constellations, should be easily visible. By the end of the month Aquila will be above the horizon by around 11pm. The brightest part of the Milky Way visible to us in the UK runs through the Summer Triangle and down through Scutum and Sagittarius.

The Plough is still very high in the sky for most of the night, standing on its handle, so Cassiopeia, the W shaped 'Lady in the Chair',  on the opposite side of the Pole Star is very low down in the north.

Bootes, the herdsman, is now riding high although only Arcturus, the brightest star in the celestial northern hemisphere, is above magnitude 2, so its kite asterism may not be easily visible in our light polluted skies. Arcturus is easy to find though - just follow the arc of the Plough's handle down to the south until you come to Arcturus.  Carry on the arc a bit further and you come to the star Spica, the brightest star in Virgo.

At this time of year when you look up to the south you are looking out of the plane of our Milky Way galaxy instead of along it like you do in winter and summer, so there aren't many bright stars, open star clusters and nebulae. However, if you've got a telescope this is a good time of year to hunt down globular clusters like M13, the Great Globular Cluster in Hercules, and faint galaxies like the many galaxies lying in the bowl of Virgo and into Coma Berenices.

Planets

Mercury:  moving through Cetus, Pisces, Cetus again, Aries and Taurus,  mag 0.3. A morning object, barely visible in May despite brightening to mag -1.6 by month end, as it rises less than half an hour before the Sun throughout.

Venus:  in Taurus mag -3.9. Unmissable in the western sky after sunset. (weather and tall buildings permitting).  On 1st it sets at 23.14 and is 17 degrees above the horizon as the sky darkens around 21.00.  It gets lower in the sky during the month as the angle of the ecliptic decreases, but its apparent distance from the Sun is still increasing. On 17th the 7% lit Moon passes 5 degrees south of the planet.  It moves into Gemini on 20th, by which time it will have brightened to mag -4.0.  By 31st it sets at 00.15, two and three quarter hours after the Sun.     

Mars:  in Sagittarius,  mag -0.4. Getting brighter during May as it gets closer to us.  On 1st it rises at 02.27 and reaches an altitude of 11 degrees in the south before the sky begins to brighten. On 6th the 68% Moon passes 2.5 degrees to the north west. It moves into Capricorn on 15th and will be at mag -0.7.  On 31st, when it will have reached mag -1.2, it rises at 01.12 and culminates at 05.06, soon after Sunrise.  Its brightness and orange red hue will mean it easily stands out against the fainter stars of Capricorn.

Jupiter:  in Libra,  mag -2.5. Shining brightly for most of the night throughout May.  On 1st it is just above the horizon as the Sun sets and should be easily visible by about 22.00.  It culminates at 01.41, when it will be 20 degrees above the southern horizon.  Reaches opposition on 9th, when it is at an altitude of 21 degrees at around 1am (midnight in real time).  On 27th it is 3.5 degrees from the almost full Moon.  On 31st it culminates at 23.25.   This month is a good time to look at Jupiter through a scope, even a fairly small one should show the 2 main belts and the 4 Galilean moons. A slightly larger instrument should show more detail, including the great red spot. There are several moon and shadow transits this month.  Details can be found in any astro mag.

Saturn:  in Sagittarius, mag 0.4. On 1st it rises at 01.20 and culminates just before Sunrise, 13 degrees above the southern horizon at dawn.  On 15th, the three quarter Moon passes the planet 3.5 degrees to the east.   Saturn also brightens during the month, reaching mag -0.2 by 31st, when it culminates at 03.07.  It's still very low, 14 degrees above the southern horizon, just above the Teapot asterism.  However, the rings are wide open, so it's worth looking at through a scope if you have a viewing site with a low, clear southern horizon.

Uranus:  not visible

Neptune:  in Aquarius, mag 7.9. Not visible for most of May, rising only 17 minutes before the Sun on 1st.  By 31st it rises at 02.15,  2.5 hours before Sunrise but still doesn't get much above the horizon as the sky brightens. WARNING:  Don't try to observe it through a scope at this time - catching even the first rays of the rising sun would blind the observer.

Dwarf Planets

Ceres: in Cancer, mag 8.4. A possible target for a small scope.  On 1st it sets at 04.53 and at 02.54 on 31st, when it is 21 degrees above the horizon at dusk.

Haumea in Bootes, mag 17.3, and Makemake in Coma Berenices, mag 17.0, are both quite well placed this month but are out of range of amateur scopes,  They could, however, be targets for keen astrophotographers.

For exact positions of all solar system objects at any time see:
Dwarf planets can be found under 'asteroids'

Meteors

One major shower. Eta Aquarids, active April 19th to May 28th,  date of peak varies according to information source but the majority give it as the early hours of 6th or 7th.  ZHR 10 - 30.  They are fast moving (42 mps) meteors, some with trails, originating from debris left by Halley's Comet. The shower is best seen from further south - between the equator and the tropic of Capricorn the ZHR could be as high as 60.  From here the radiant rises just before dawn, unfortunately this year the Moon rises at 01.26 on 6th and 02.28 on 7th, so will seriously interfere.  Rates are said to be quite good for a few days either side of the peak but the Moon will be in the way in the early hours throughout this period.

Eta Lyrids,  active 3rd to 12th, peak 9/10th. ZHR 3, although as usual some sources disagree and give a figure as high as 7.   Parent comet is C/1983/H1 (IRAS Araki - Alcock) and the shower is best seen just between 2am and dawn.  The Moon rises at 03.48 on 10th, giving just under 2 hours of optimum viewing conditions - as always, weather permitting. 

The Antihelion Source (meteors, having a radiant on the ecliptic opposite the position of the Sun, which can't be attributed to a particular shower) is active in the latter part of May:  ZHR 1-3.

There are also several daytime showers in late May but they can only be detected using radar or radio equipment.

Comets

Still nothing brighter than mag 10.5.  The next possible naked eye comet is 21P  Giacobini-Zinner, currently magnitude 15.7, which is predicted to reach naked eye brightness in late August and September.

For positions of comets which are currently visible see;
www.cometwatch.co.uk/current-observable-comets/

The night sky in April 2018

posted 30 Mar 2018, 12:40 by Pete Collins   [ updated 30 Mar 2018, 15:24 ]

by Anne Holt

Sunrise:    1st    06.42           30th     05.36
Sunset:     1st    19.44           30th     20.36

Astronomical Darkness
1st:    21.50  to  04.34      30th    23.21  to  02.49

New Moon:  16th at 02.57
Full Moon:   30th at 01.58

This full Moon is known as the Pink Moon because many flowers of this colour bloom in April. No Lunar eclipse this month, so it won't appear pink. In Old English/Anglo Saxon it was known as the Egg Moon.

Highlights - and lowlights

No more HPAG meetings until late September, fewer and fewer hours of darkness, and as for true astronomical darkness only 6hrs 44m on 1st and a measly 3hrs 28m on 30th.  And let's not forget the proverbial April showers which mar many a night's observing.
On the plus side Venus and Jupiter are both shining brightly, their positions still improving as the month goes on.  We have the Lyrid meteor shower peaking on 22nd, the likelihood of bright fireballs and, though there won't be anything to see, Uranus makes a rare move. There are bright mid evening passes of the ISS every evening from 1st to 6th.

On 1st we have Easter Sunday, which could be considered to be an astronomical event because of the way it's calculated - it's the first Sunday after the first full Moon on or after the Vernal equinox. For anyone who may be interested, the earliest possible date for Easter Sunday is March 22nd. This happens only very rarely, the last time was in 1818, the next will be 2038.  The latest is April 23rd, not nearly so uncommon:  last in1943, next time in 2038.  The most common date is April 19th.  And, though the sequence of dates may appear to be completely random, it isn't - it starts to repeat itself after 5,700,000 years.

Constellations

Now that BST has been forced upon us, we have to wait even longer for the skies to darken each evening. By the time it gets really dark the winter constellations, including the beautiful area around the Winter Hexagon, so rich in bright stars, is sinking slowly in the West.

Ursa Major is now high in the sky with the Plough overhead around midnight in the second half of the month. Follow the curve of the handle down to the orange coloured Arcturus, brightest star in the constellation Bootes the herdsman, and the 4th brightest in the night sky.
The signature constellation of spring, Leo, is still riding high in the south and the Summer Triangle of Vega (in Lyra), Deneb (Cygnus) and Altair (Aquila) is now rising in the east and visible in the early hours.

Planets

Mercury:  in  Pisces, mag 5.8. At inferior conjunction on 1st and is not visible, rising only 18 minutes before the Sun. It hardly improves during the month, on 30th it rises at 05.07, only 29 minutes before sunrise.  It will have brightened to mag 0.3 by 30th  but is hardly visible as it is still below the horizon as the sky brightens. 

Venus: in Aries, mag -3.9. An evening object, its position improving throughout April but still to reach its best.  On 1st it sets at 21.11, almost 2 hours after Sunset, and is  12 degrees above the horizon as the sky darkens. It moves into Taurus on 20th and from 22nd to 26th passes south of the Pleiades.  By month end it has moved to the north of the Hyades, is 17 degrees above the horizon at 9pm and sets 2 and a half hours after the Sun.

Mars:  in Sagittarius, mag 0.3. Still quite low in the sky.  On 1st it rises at 03.24 and reaches an altitude of 11 degrees above the horizon before the sky starts to brighten.  It appears close to Saturn, separated by less than 2 degrees on 2nd, when they are both north of the Teapot asterism.  Mars then moves away following a path eastwards between the Teapot and the less obvious Teaspoon asterism.  By month end it will have brightened to mag -0.3, rising half an hour after midnight but still not culminating in darkness.  The distance between Mars and Earth is now decreasing so the planet appears larger when seen through a scope.

Jupiter
:  in Libra, mag -2.4. Dominating the sky for most of the night during April.  On 1st it rises at 23.22, culminating at 03.51, when it will be 19 degrees above the southern horizon.  It is close to the gibbous Moon on 3rd/4th.  It  brightens slightly during the month, mag -2.5 on 30th, when it rises at 21.11 and culminates at 01.46.

Saturn
:  in Sagittarius, mag 0.5. Rises at  03.18 on 1st and reaches an elevation of 12 degrees by the time the sky brightens.  Best seen between 05.0 and 06.00.  On 30th it rises at 01.24 and culminates half an hour before sunrise, reaching an altitude of 13 degrees before the sky brightens.  It will  be slightly brighter at mag 0.4.

Uranus: in Pisces, mag 5.9. Not easy to see this month, even at the beginning - on 1st it sets about 90 minutes after the Sun, a couple of hours before astronomical darkness begins.  Conjunction is on 18th, when the planet appears only 3 degrees from the Sun, so can't be seen.  It then becomes a morning object but still not visible - on 30th it rises only 15 minutes before Sunrise.  However, Uranus does undergo a rare change in April.  Because it takes 84 years to orbit the Sun it remains in each Zodiac sign for an average of 7 years,  On April 28th it moves into Aries, where it will remain until March 2025.

Neptune
: not visible

Minor planets


Ceres
, in Cancer, mag 7.9. Should be visible in good binoculars and small telescopes, especially in early April, but only as a point of light as it is so small. On 1st it culminates at 21.12 and is 67 degrees above the southern horizon. By month end it will have faded to mag 8.4, setting at  04.57.

Haumea
, in Bootes, mag 17.3. Reaches opposition on 14th but is out of reach of most amateur scopes.  However it is a possible photographic target as it moves slowly eastwards below Arcturus.

Makemake, in Coma Betrenices, mag 17.

For more information on planetary positions, see
https://in-the-sky.org/ephemeris.php
Minor planets come under the heading 'Asteroids'.

Meteors

One fairly major shower this month.

Lyrids, active 14th - 30th, peak 22nd,  ZHR 18 - 20. This is the earliest known shower, recorded in 687BC by Chinese astronomers who said that meteors 'fell like rain'.  Not nearly so prolific now but occasionally puts on a spectacular show, the last time in 1982 when a ZHR of 90 was recorded. These are medium paced meteors, average mag around 2.  Their parent comet is C/1801G Thatcher, which we will never see.  It last came close to the Sun in 1861 and won't return until 2276.  The shower is best seen, this year, on the morning of 22nd after the 48.5% lit Moon has set at 02.34.

A few minor showers are mentioned on various sites, however these are not in the International Meteor Organisation calendar,  and sources don't always agree on dates - or anything else.

Gamma Virginids: active 5th - 21st, peak 14/15th  (some sites say there is no definite peak)  ZHR 5

Delta Draconids:  active March 28th to April 12th.  ZHR 5. Very slow moving meteors, leaving trails.  Best seen around midnight.
Some sources give 2 separate showers - Delta Draconids,  March 13 to April 17th, peak March 31st to April 2nd,  and Tau Draconids, March 28th to April 12th, peak April 1st.

Alpha Bootids:  April14th to May 13th, peak April 28th.  Very slow moving leaving fine trails.  This shower could include fireballs.

April fireballs:  Active from 14th -20th,  Meteors of mag -3 or brighter with no specific radiant.  They appear to come from the SE area of the sky.

And the Antihelion source is active in the first half of the month and again near the end.   These are meteors not belonging to any particular shower, having a radiant on the ecliptic, oposite the position of the Sun.


Comets

Again, there are several very faint comets around, none brighter than mag 10.5. One worth mentioning is C2016R2 (panSTARRS)  mag 11.0. moving from Perseus into Auriga,towards Capella.  Notable  for its bright blue tail. For more information, see www.cometwatch.co.uk/current-observable-comets/

The night sky in March 2018

posted 28 Feb 2018, 01:52 by Pete Collins

by Anne Holt

Sunrise        1st:   06.57       31st:    06.45  (BST)
Sunset         1st:   17.46       31st:    19.42    "

Astronomical darkness 
 1st:   19.12 -  04.58      31st:  21.47 - 04.37  "  

British Summer time begins on Sunday 25th at 01.00, when the clocks go forward one hour.
The Vernal Equinox. when the centre of the Sun's disc crosses the plane of the celestial equator, is on 20th at 16.15.  Despite the name, day and night are not equal then - the day is 12hrs 10 mins 19 seconds long.   The closest day to 12 hours is 18th at 12h.01m.46s. 

Full Moon:    2nd at 00.51  and  31st at 13.36
New Moon:   17th at 13.11

The full Moon on 2nd is known as the Worm Moon because it is when the ground begins to soften after the Winter frosts and worms reappear.  (but maybe not this year).  It is sometimes known as the Lenten Moon - for obvious reasons.
The second one is, of course, another Blue Moon - but just a regular one this time.

Highlights

Again, not a lot in the way of things to look forward to.  Planetary positions are improving slightly, with Jupiter rising earlier and Venus setting later, but neither has yet reached its best for the year.  The Moon passes through the Hyades on 22nd, occulting several of the stars.  It passes in front of Aldebaran soon after 23.30 but they will be very low in the sky by this time.
What we really need to do this month is to appreciate the things we'll soon have  to say goodbye to until next Autumn, so enjoy them while you can.   Orion, the most beautiful constellation in the sky is setting soon after 11pm by the end of March, we have less astronomical darkness: fewer than 7 hours at month end,  BST is imposed on us from 25th and, worst of all, our last meeting of the season is on 29th.

Constellations

We are now losing the winter highlights of Orion, Sirius and Taurus soon after midnight, though they are still promiinent in the south in the early part of the night.
Auriga, with the bright yellowish-white star Capella, is now overhead soon after sunset, with Gemini and Leo also prominent. The not very obvious zodiac constellation, Cancer, is now well placed. The Plough is overhead by midnight, the handle pointing to the orange hued Arcturus, the brightest star north of the celestial equator, in the constellation of Bootes. By the end of March the Summer Triangle will be above the horizon soon after 2am - or by 1am if you've forgotten to put the clock forward.
 
Planets

Not the best time for planetary observation, all the naked eye planets are very low in the sky, even at their highest point.

Mercury:  in Aquarius, mag  -1.3. Not visible in the first few days of the month,  on 1st it sets about 80 minutes after the Sun but is only 6 degrees above the horizon as the sky darkens.  On 3rd it moves into Pisces and a few days later may be glimpsed briefly soon after Sunset.  On 6th it will be at an altitude of 8 degrees at 18.00.  The following couple of weeks is the best time this year to see it, it will be higher in the sky as darkness falls - 12 degrees on 13th - but will have faded to mag -0.7.  It reaches Greatest Eastern Elongation on 15th, when it sets 1hr 45 minutes after the Sun, but is down to mag -0.4.  It fades rapidly during the rest of the month, mag 0.3 on 19th and 1.1 on 22nd, when it will be very low in the West at dusk.  It won't be visible by month end as it appears only 4 degrees from the Sun and will have faded to mag 5.3.

Venus:  in Aquarius, mag 3.9. Appears close to Mercury in the early evening sky for much of March.  On 1st it sets at 18.46 about an hour after the Sun but will be only 6 degrees above the horizon at dusk.  It moves into Pisces on 3rd, when it appears only one degree left of the much fainter planet, neither easy to see as they are very low in the darkening sky.  Venus sets 3 or 4 minutes later each night and, after the first few days of March, should be more easily visible, low in the West at dusk. It spends a couple of days (13 & 14th) in the non Zodiac constellation of Cetus the whale before moving back into Pisces for the rest of the month.  On 18th, Venus, Mercury and the 1% lit Moon will appear in a straight line about 30 minutes after Sunset, with Venus in the middle at an altitude of 10%, Mercury slightly higher and the Moon very low.  By the last week of the month Venus is still getting higher in the evening sky, leaving Mercury behind. On 31st it is 12 degrees above the horizon at dusk and sets at 21.28.

Mars:  in Ophiuchus, mag 0.8. On 1st it rises at 03.03 and reaches its highest point at 06.49.  Because of its relatively fast Eastward movement it rises less than a minute earlier each day.  Moves into Sagittarius on 12th.  It is now getting closer to Earth so during the month will brighten, and the disc will appear to be increasing in size when seen through a scope.  However, the downside is that it remains very low in the sky, no higher than 11 degrees throughout March.  On 31st, when it will be at mag 0.3, it rises at 03.26 and culminates after Sunrise.

Jupiter:  in Libra, mag -2.2. Rises at 00.32 on 1st, and reaches its highest point, 19 degrees above the S horizon, just before 5am - as astronomical darkness ends.  It rises 3 or 4 minutes earlier each day,  before midnight after the first week of the month.  Like Mars it appears to increase in size during March, and also brightens slightly.  It ends the month at mag -2.4, rising at 23.36 and culminating at 03.56.

Saturn:  in Sagittarius, mag 0.6. Visible low in the pre dawn SE sky, a little to the North of the teapot asterism.  Rises at 04.14 on 1st but is best seen after 11th, when it will be 11 degrees above above the horizon as dawn breaks.  On this day it is just 2 degrees from the 34% lit Moon.  At month end it rises at 03.22 and will be at mag 0.5.  During the month the slightly brighter and much more reddish hued Mars appears to be moving towards Saturn, on 31 st they will be separated by only 1.5 degrees.

Uranus:  in Pisces, mag 5.3. On 1st it is 24 degrees above the Western horizon as the sky darkens, setting a few minutes after 22.00.  Sets a few minutes earlier each day and is soon lost in the evening twilight.  On 28th it is only a quarter of a degree from Venus but too faint to be seen with the unaided eye.  Might be visible in binoculars but DO NOT point binoculars or a scope at Venus until the Sun is fully below the horizon.

Dwarf Planets
Makemake is at opposition on 24th but at a mag of only 17 won't be visible in most amateur scopes.  Could be a possible photographic target as it passes through Coma Berenices in a NW direction.
At mag 7.6 Ceres, in Cancer, is a much better bet for telescopic observation.  On 1st it culminates at 22.23, about 68 degrees above the S horizon.  On 31st it culminates at 21.16.  

For more information on the position of planets, dwarf planets and other Solar system objects see  https://in-the-sky.org/ephemeris.php  or https://theskylive.com

Meteors

Another bad month for meteor spotters in the Northern hemisphere.  If you do happen to be South of the equator there is the Gamma Normids which peak on 16th with a ZHR of 6.
From our latitudes the best we can expect is several small showers with radiants in Virgo - the pi Virginids (peak between 3rd & 9th), eta Virginids (peak 18th) and the theta Virginids (peak 20th), all with a ZHR of 3 or less.  The International Meteor Organisation now classes these as part of the antihelion source as the radiants are very close and the showers almost impossible to separate.

Comets

There are still several faint comets around but none are brighter than mag 10.5.  For anyone who wants to try their hand at photographing these, more details can be found in www.cometwatch.co.uk/current-observable-comets/

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