Constellations, planets, meteor showers etc. on show this month. |
The night sky this month
The night sky in December 2018
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: https:/theskylive.com 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. |
The night sky in November 2018
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
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
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. |
The night sky in August 2018
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 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. More info on www.cometwatch.co.uk comet positions also given in in-the-sky.org |
The night sky in July 2018
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
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.
|
The night sky in June 2018
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
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
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
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. ConstellationsWe 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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