Constellations, planets, meteor showers etc. on show this month. |
The night sky this month
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/ |
The night sky in February 2018
by Anne Holt Sunrise: 1st 07.54 28th 06.59 Sunset: 1st 16.51 28th 17.44 Astronomical darkness: 1st: 18.52 - 05.51 28th: 19.40 - 05.01 Highlights Not
much to highlight this month. Jupiter is shining brightly in the
morning sky and, towards month end, Venus re-appears as an evening
'star'. The Sun is rising a couple of minutes earlier and
setting a couple of minutes later each day now, but we still have quite a
long period of astronomical darkness - 11 hours on 1st and a little
over 9 hours on 28th. However, by month end, astronomical twilight
doesn't end until 19.40 - almost half way through our meeting time. On
15th there is a partial Solar eclipse, but it's only visible much
further South - in parts of S America, the Southern Pacific &
Atlantic oceans and Antarctica. There are some bright early evening passes of the ISS in the first half of the month. See www.heavens-above.com for details. One of the most
interesting things this month is something that doesn't happen. We have
what is referred to as a Black Moon, meaning a calendar month with no
full Moon. This can only happen in February and is quite rare, the
last time was in 1999 and the next won't be until 2037. Black Moon
isn't a recognised astronomical term and is also used to describe the
second new Moon in a month or the third new Moon in a season with 4.
Both of these seem to make more sense, referring to something which does
happen, rather than something which doesn't. Orion and Taurus are now above the horizon as the sky darkens but start to set at around 2am at the start of February and soon after midnight by the end of the month. Gemini and Auriga are still prominent, remaining above the horizon until the early hours. Leo, the signpost constellation of Spring, is now high in the sky for most of the night and Bootes, with it's bright red star Arcturus is rising soon after 11, and around 9 at month end. In the early part of the evening the Plough is low in the North East standing on its 'handle', and Cassiopeia high in the North West as darkness falls. By month end, the Summer Triangle will have risen soon after 3am - Summer already? Someone better tell the weather. Planets Mercury: in Capricorn, mag -0.6. At
the start of February it rises only 14 minutes before the Sun and won't
be visible in the bright pre dawn sky. On 17th it moves into Aquarius
on the same day as it reaches superior conjunction, the furthest point
in its orbit from Earth, on the opposite side of the Sun. It then
becomes an evening object but still not easily seen. By the end of Feb
it sets at 18.27, only 45 minutes after the Sun, and will have
brightened to mag -1.4. Venus: in Capricorn, mag -3.9. An
evening object. At the start of February it sets only 18 minutes after the
Sun, so won't be visible despite its brightness. It moves into Aquarius
on 9th and by mid month might be seen very low in the West, soon after
Sunset. On 28th it sets at 18.42, almost an hour after the Sun, and
will appear very close to the ten times fainter Mercury. Mars: in Scorpio, mag 1.2. A
morning object, rising soon after 3am throughout February. On 1st this
is about 3 and a half hours before sunrise. On 9th it moves into
Ophiuchus. It spends most of February quite close to the 'rival of
Mars', red supergiant Antares, at their closest - about 5 degrees apart -
on the morning of 12th. because Mars is still relatively distant from
Earth, it is still quite faint and will appear similar in brightness to
the star, as well as in colour. At around 4.30 on the morning of 9th,
the 35% lit Moon joins them to form a straight line. Jupiter; in Libra, mag -2.0. Shining
brightly in the morning sky. On 1st it rises at 02.12 and culminates
at 06.39, just as the sky begins to brighten. By month end it will be
slightly brighter at mag -2.2, rising just an hour after midnight and
culminating while the sky is still at its darkest. Saturn: in Sagittarius, mag 0.6. Rises
a couple of hours before the Sun at the start of February, but is very
low in the SE brightening sky. On the morning of 11th the 18% lit Moon
will be just 4 degrees NW of the planet. By the end of the month it
rises at 04.25, 2 and a half hours before the Sun, while the sky is
still dark. It will still be very low - only about 8 degrees - and
difficult to see. Uranus: in Pisces, mag 5.8. The
only planet which is currently in the northern celestial hemisphere is
now past its best for observing. On 1st it sets just before midnight,
having reached its highest point in the sky as the Sun sets. By the end
of the month it will have faded slightly to mag 5.9 and be setting a
few minutes after 10pm. Neptune: in Aquarius, mag 8.0. At
the start of February it sets only 2 hours after the Sun and, by month
end, at 18.00 - only 16 minutes after Sunset, so not visible. Dwarf Planets Ceres,
in Cancer, is still very well placed for amateur observation,
especially in the early part of Feb, when it is just past opposition and
is at mag 6.9. On 1st it culminates at 00.41, by month end it reaches
its highest point at 22.23 and will have faded to mag 7.3. Because it
is so small, it will only ever show as a point of light in amateur
scopes so is probably best as a photographic target. Eris
in Cetus, Haumea in Bootes and Makemake in Coma Berenices are all well
placed this month, but at magnitudes of around 17 to 18 are out of range
of amateur scopes. If you really want to try imaging them, exact positions can be found on This site also gives positions of major planets, asteroids etc. Meteor Showers Unless
you happen to be in the southern hemisphere, when the alpha Centaurids can be
seen between Jan 31st and Feb 20th, this month is very poor
for meteors. Some sites mention the delta Leonids,
active Feb 5th to March 19th, peak 22nd, ZHR 3. These are said not to
be associated with any particular comet but to be caused when the
Earth passes through a dust cloud across its orbit.However,
the International Meteor Organisation no longer includes this in their
listings, so maybe it was more temporary than first thought. Comets There
are still several faint comets around but none brighter than mag 10.5.
If you do want to try your luck photographing one of these, details can
be found on The next reasonably bright comet expected in our skies is 46P/Wirtanen, which is predicted to reach mag 3 in December. But we all know what comets are like, so don't hold your breath! |
The night sky in January 2018
by Anne Holt The Winter HexagonSunrise: 1st 08.24 31st 07.55 Sunset: 1st 16.00 31st 16.49 Astronomical darkness 1st: 18.10 to 06.14 31st: 18.51 to 05.53 Full Moon: 2nd at 02.24 and 31st at 13.26 New Moon 17th at 02.18 The Earth reaches perihelion (closest point in its orbit to the Sun) on Jan 3rd at 05.35, when it will be at a distance of 147,097,000 km. Highlights This month we have 2 Supermoons, more correctly known as perigee-syzygy Moons: perigee meaning closest point to Earth, syzygy meaning 3 celestial bodies in a straight line. We have a reasonable meteor shower, ruined this year by bright Moonight (or, more likely, clouds), a dwarf planet at opposition, and the ISS is back in the evening sky from 26th. We still have a good amount of astronomical darkness, a few minutes short of 12 hours at the start of the month and nearly 11 hours at the end - long enough to enjoy the beautiful rich winter skies. We hope! Constellations There
isn't much change in the prominent constellations since December, just
that everything rises, or sets, a couple of hours earlier. Orion
is now well above the horizon by 8pm at the start of the month, with
Sirius rising at this time. By month end, Sirius will rise at about
6pm. Auriga, Gemini and Cassiopeia are all high in the sky. The Summer Triangle is now setting earlier as the Winter Hexagon rises.
Taurus and the Pleiades are still very prominent and the spring constellation of Leo is above the south eastern horizon by 9pm. PlanetsMercury: in Ophiuchus, mag -0.3. Reaches Greatest Western Elongation on 1st but is still very low in the sky despite rising nearly 2 hours before the Sun. It might just be visible from a site with an unobstructed SE horizon. It moves into Sagittarius on 9th and between 12th and 15th it appears very close to Saturn. On 13th they are separated by a little over half a degree, both rising about an hour before the Sun. It won't be visible at all in the later part of January, on 31st it rises only 15 minutes before the Sun. Venus: in Sagittarius, mag -3.9. Not visible for most of January, on 1st it rises only 3 minutes before the Sun. It reaches superior conjunction on 9th and moves into Capricorn on 18th. By month end it will be an evening 'star' but still not easily seen as it sets only 17 minutes after Sunset. Mars: in Libra, mag 1.5. Another morning object, visible in the pre-dawn sky. On 1st it rises at 03.34 almost 5 hours before sunrise. During the first week of January it appears to move towards Jupiter, closest on the morning of 7th, when they are separated by only about a quarter of a degree. By month end, when it rises 4.5 hours before the Sun, it will have brightened slightly to mag 1.3 and be close to Antares - the red supergiant in Scorpio. Jupiter: in Libra, mag -1.8. Increasingly conspicuous in the morning sky, on 1st it rises at 03.49 and culminates at 08.23, as the sun is rising. By month end, when it will have brightened to mag -2, it rises at 02.15 and culminates only 45 minutes after the end of astronomical darkness. Saturn: in Sagittarius, mag 0.5. Now a morning object but not visible for most of the month. On 1st it rises only 43 minutes before the Sun. By month end that is increased to 2 hours, so it might possibly be seen from somewhere with a low, clear SW horizon. Uranus: in Pisces, mag 5.8. Only visible in the earlier part of the night this month. On 1st it is high in the sky, about 46 degrees, soon after the start of astronomical darkness and sets around 2am. On 31st it sets just before midnight. Not really a naked eye object, except in ideal conditions. Should be visible in decent binoculars. Neptune: in Aquarius, mag 7.9. Not easy to see after the first week in January. On 1st it sets at 21.37, on 31st at 19.44 during astronomical twilight. Recommended websites for more info on positions of planets and other Solar System objects https://in-the-sky.org https://theskylive.com The Moon The Moon warrants its own section this month. We
have 2 full Moons, the first on 2nd at 02.24. is known as the Wolf Moon
- so called by Native Americans as this is the time when hungry wolves
are likely to be howling. On 31st at 13.36 we have the Snow Moon. This
is a Blue Moon, if we use the newer definition of the second full Moon
in a calendar month. Both these full moons can be called Supermoons, as their apparent size is 90% or more of the maximum possible. The
first of these is the largest of 2018, slightly bigger than the one in
December. It occurs only 4 and a half hours after perigee. On
31st, there is a total lunar eclipse. unfortunately only visible on the
opposite side of the Earth - parts of NE Europe, Asia, Australia, NZ
and the Pacific Ocean. If you do happen to be in the right
area at the time of totality, you will, weather permitting, be treated
to the sight of a blood red blue Supermoon. Or should that be a blood
red Super blue Moon? Meteor Showers One fairly strong shower in January. The
Quadrantids, active 1st -10th, peak on the night of 3rd/4th, Estimates
of ZHR varies according to source used, 25, 40 or even more. This
shower has a very short peak, only about 6 hours. They are medium paced
meteors not usually leaving trails. The shower often includes bright
fireballs. It is named after the former constellation Quadrans Muralis,
now part of Bootes, and is thought to originate from dust left by
asteroid 2003 EH1, probably the remains of extinct comet C1490X1. This year only the very brightest meteors will be visible because of the proximity of the very bright just-past-full Moon. Minor Showers Ursa Minorids: active 10th - 22nd, peak 18th, ZHR 3. Not much information about this one. However conditions will be favourable, no Moon interference. The
Antihelion Source - meteors not belonging to any particular shower,
having their radiant on the ecliptic, opposite the position of the Sun -
is active in early January. ZHR around 3. Kappa
Cancrids: Again, not much information. Possible activity around 21.00
on 9th. The radiant of these is very close to the Antihelion Source but
the meteors should be distinguishable as these are faster moving. Comets There are still several faint comets around, none naked eye or even binocular Well positioned are: Pan
STARRS (2016P2) mag somewhere between 10.5 and 13.2 (as always, sources
fail to agree). Moving in a NW direction through Taurus, in the first
week of the month it passes below the bottom star of the Hyades, the V
shaped group of stars in Taurus. it's at its closest on 5th & 6th.
It ends the month a few degrees east of the Pleiades. Heinze
(2017T1) Currently mag 13 but expected to brighten during January,
maybe to around mag 9. Moving eastwards through Lynx, Camelopardis,
Cassiopeia and finishing the month in Pegasus. For details of all visible comets, see Finally Dwarf
planet Ceres, in Cancer, reaches opposition on 31st, at a distance
from Earth of 1.6AU. Best seen around midnight when it will will be at
its highest point, about 42 degrees. It will be at mag 6.8, so an easy
target for amateur scopes and photographers. However, even though it is
by far the largest object in the Asteroid Belt, accounting for about
25% of the total mass, it is too small to appear as anything other than
star like. For exact position at any time, see https://in-the-sky.org/news.php?id=20180131_13_100 |
The night sky in December 2017
by Anne Holt Sunrise 1st: 08.01 31st: 08.25 Sunset 1st: 15.53 31st: 15.59 Astronomical darkness 1st: 18.01 to 05.54 31st: 18.09 to 06.14 The Winter Solstice is Thursday 21st at 16.27, the shortest day at 7 hours 28 minutes 39 seconds. It is also the day of the HPAG Christmas party. Latest Sunrise: 29th & 30th, 08.25 Earliest Sunset: 13th, 15.49 Full Moon: 3rd Dec at 15.46, known as The Cold Moon for obvious reasons. New Moon: 18th Dec at 06.30 Highlights This
month we have one major meteor shower and a few minor ones, around 12
hours of astronomical darkness each night, we have the shortest day and,
more importantly for astronomers, the longest night. On the
night of 30th/31st the Moon passes the Hyades - the V shaped Head of the
Bull asterism in Taurus. Aldebaran, the Eye of the Bull, is occulted
in the early hours of 31st, disappearing a few minutes after 1am and
reappearing about 15 minutes before 2am. We also have a
perigee-syzygy Moon. OK, call it a Supermoon if you really must. It
will be the biggest and brightest full Moon of the year - though the
next one, in early Jan, will be even better. 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 Sagittarius, mag 0.2. Not easy to see this month, it starts December as an evening object, very low in the SW after sunset. On 1st it sets at 16.47, just over an hour after the Sun. On 6th, when it has faded to mag 1.5, it is only 1.5 degrees from Saturn - the pair may be visible, from a site with an unobstructed SW horizon, about 25 minutes after sunset. On 10th it moves into Ophiuchus and 2 days later reaches inferior conjunction. It then becomes a morning object. On 15th it is 2 degrees from Venus, but both are very low in the SE and very difficult to see. On 17th it is at mag 2.4 and lies 1 degree South of the very thin crescent Moon. By 31st it rises almost 2 hours before the Sun and will have brightened to mag -0.2. Venus: in Libra, mag -3.9. Another planet which appears very close to the Sun this month. On 1st it rises about an hour before it, then a few minutes later each day. It may be seen for a short while before Sunrise in the first week of December. Moves into Scorpio on 4th, Ophiuchus on 8th and Sagittarius on 23rd. On 31st it rises only 5 minutes before the Sun. Mars: in Virgo, mag 1.7. Because of its relatively fast eastward motion against the background stars it rises around the same time throughout December, 03.42 on 1st, then about quarter of a minute earlier each day. it also brightens very slightly during the month as its position improves. On the morning of 25th it rises at 03.36 and should be visible for a while before the sky brightens. However it is hardly a Christmas star in the East, at a mag of only 1.5. On the morning of 31st it rises almost 5 hours before the Sun and is 3 degrees from the much brighter Jupiter. Jupiter: in Libra, mag -1.7. Another improving morning object. On 1st it rises at 05.17, then 2 or 3 minutes later each day during the month. On 25th it rises at 04.10 and, at mag -1.8, is a much better candidate for the Christmas star. On 31st it rises at 03.52 and culminates at 08.26, just as the Sun is rising. Saturn: in Sagittarius, mag 0.5. Appears very close to the Sun throughout December. On 1st it sets at 17.04 and might be seen very close to the SW horizon soon after Sunset. Unlikely to be visible after the first few days of the month as it approaches conjunction on 21st. By month end it is a morning object, rising just over an hour before the Sun on 31st. Uranus: in Pisces, mag
5.7. Once again this is the best positioned planet for observing - it's
a pity that it isn't a bright naked eye object. On 1st it reaches it's
highest point in the sky at 20.58 and sets at 03.55, 2 hours before
astronomical darkness ends. By 31st it is culminating 2 hours earlier
and sets around 2am. During the month it fades slightly, to mag 5.8,
still theoretically a naked eye object - if both the conditions and the
eye in question are perfect. Binoculars or, better still a telescope,
should show the small blue green disc. Neptune:
in Aquarius, mag 7.9. Past its best now, visible only in the early
part of the night. On 1st it culminates at 18.18. soon after
astronomical darkness begins, and sets 20 minutes before midnight. By
month end it culminates just after Sunset and sets at 21.41. It may be
visible in good binoculars under ideal conditions but is best seen in a
telescope in order to see its rich blue colour. Meteor Showers One
major shower, the Geminids: active Dec 4th to 19th, peak in the early
hours of 14th. ZHR could be as high as 120 but is likely to be far
fewer. These bright, medium speed meteors are the only major shower
which originate from an asteroid - 3200 Phaethon - rather than a comet.
This shower often has near maximum rates for several hours either side
of the peak. The 13.5% lit Moon rises at 03.53 on 14th, so won't cause
too much interference. Minor showers Ursids,
active Dec 17th to 26th, peak 22nd, ZHR usually 5 -10 but can be as
many as 25. Occasional outbursts of 50 per hour have been observed -
last seen in 1945 and 1986. These are medium paced meteors, parent
comet 8P/Tuttle. The Moon sets at 20.09 on 22nd so no interference. Leo Minorids, active Dec 5th to Feb 4th, peak 20th, ZHR 5. A weak but long lasting shower. Coma
Berenicids, active 12th to 23rd, peak 16th, ZHR 3. Another weak shower
best seen around 1am when the radiant is high in the sky. Again, no
Moon interference. These were once thought to be part of the Leo Minorids but are now regarded as a separate shower. Minor planets and Asteroids Two
days after the peak of the Geminids, its parent object, asteroid 3200
Phaethon passes Earth at a distance of only 10.3 million Km/6.4 million
miles. At maximum mag 10.9 it isn't visible to the naked eye but might
be of interest to astrophotographers. For exact position on any day see https://in-the-sky.org/data/object.php?id=25877 (or id=a3200 which appears to be exactly the same) Ceres in Leo and Makemake in Coma Berenieces are both well placed for imaging. For more info on these, and all planets, minor planets and asteroids see:- Comets No comets brighter than mag 10 this month, however for astrophotographers, we have several between mag 11 & 17. or https://in-the-sky.org/data/comets.php |
The night sky in November 2017
by Anne Holt Sunrise 1st: 07.08 30th: 08.00 Sunset 1st: 16.36 30th 15.54 Astronomical darkness 1st: 18.34 - 05.11 31st 18.02 - 05.53 Full Moon 05.22 on Nov 4th New Moon 11.42 on Nov 18th Highlights Not much in the way of highlights this month, the main one being that we have lots of astronomical darkness - about ten and a half hours on 1st and and almost 12 hours at the end of the month. And it starts at a reasonable time now we've gone back to proper time. The planets are still not great for naked eye observers, Venus and Saturn are past their best, Mars and Jupiter start November badly placed but their positions improve over the month. We have a reasonable meteor shower in the Leonids, a few minor meteor showers and several very faint comets, most of which are only visible in fair sized scopes. 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 Libra, mag -0.4. At the start of November it sets only a few minutes after the Sun and is not visible. Moves into Scorpio on 6th then spends most of the month along the border of that and Ophiuchus before crossing into Sagittarius on 29th. Reaches greatest Eastern elongation around midnight on 23rd/24th. On 30th it sets at 16.48, almost an hour after the Sun and will have dimmed slightly to mag -0.2. On this day it is 3 degrees South of Saturn, very low in the SW just after Sunset and still not easy to spot. Venus: in Virgo, mag -3.9. On 1st it rises at 05.22, less than 2 hours before Sunrise, and may be visible for a short time before the sky gets too bright. On the morning of 13th it is only 16 arcminutes from Jupiter, low in the SE. It moves into Libra on 14th. At the end of the month it rises only 70 minutes before the Sun and is not easy to see, despite its brightness. Mars: in Virgo, mag 1.8. A
morning object, appearing low in the sky before Sunrise. On 1st it
rises at 03.50 and might be spotted before the sky begins to brighten.
On the morning of 15th it is 3 degrees from the 9% lit Moon. Its
position improves during the month, by 31st it rises about 4 hours
before the Sun. Because of its apparent Eastward motion against the
background stars, the planet rises around 4am throughout November but
the Sun is rising a little later each day so the difference is
increasing. It is still on the far side of its orbit, relative to
Earth, so is not particularly bright and shows only a small disc when
seen through a scope. Jupiter: in Virgo, mag -1.7. Another
morning object whose position is improving during November. On 1st it
rises only half an hour before Sunrise. It moves into Libra on 15th, and
rises at 6am. The following morning Jupiter, Venus and the 1% lit Moon
form a triangle which may be seen very low in the ESE at about 06.30 -
if you are viewing from a site with a very low, unobstructed horizon.
On 30th it rises just over 2 and a half hours before the Sun - about 30
mins before astronomical darkness ends. Saturn: in Ophiuchus, mag 0.5. Unlike
Jupiter, Saturn's position deteriorates during November. On 1st it
sets 2hrs 14 minutes after the Sun, 15 minutes after the sky gets fully
dark. On 20th it moves into Sagittarius and is less than 5 degrees East
of the 4% lit Moon, very low in the West, setting at 7.42pm. At the end
of the month it sets only 75 minutes after the Sun and is not bright
enough to be seen in the twilit sky. For those with telescopes, the 2 ice giants are a much better prospect. Uranus: in Pisces, mag 5.7. Still
a good binocular target. It's the only planet currently above the
celestial equator. On 1st it reaches is highest point in the sky (46
degrees) just before 11pm and sets at 6am, about an hour before
Sunrise. On 30th it culminates at 9pm and sets at 4am. For those with
perfect eyesight, who are lucky enough to be visiting (or live in) a
dark sky site, now is a good time to try to spot it with the naked eye.
If you have average sight and live in the Manchester area you will need
good binoculars. A telescope will show the small blue/green disc. If
we get some clear nights over the next few weeks we should be able to
see it through the scopes at HPAG meetings. Neptune: in Aquarius, mag 7.9. Best seen in the early part of the night this month. On 1st it culminates at 20.15 and sets soon after 1.30, by 30th it culminates at
18.22, a few minutes before astronomical darkness begins, and sets 20
minutes before midnight. Could possibly be seen in very good
binoculars, under ideal conditions, but its blue coloured disc can only
be seen through a telescope. Recommended websites for exact positions of all planets, minor planets and asteroids are: Meteor Showers No major showers this month, but we have one reasonable one. Leonids: active November 6th to 30th, peak 18th midnight till dawn, ZHR 10. These
are very fast moving (44 miles/second) bright meteors, often leaving
trails. The parent comet is 65P Tempel-Tuttle. The Moon won't
interfere, as it doesn't rise until 6am on 17th. However, the weather
probably will interfere! Minor Showers Northern Taurids: active Oct 20th - Dec 10th. Peak 11/12th ZHR 5. Bright,
slow moving meteors, associated with the Southern Taurids, they are
thought to have originated as one shower, which later broke into 2
separate streams. Parent comet for both is the predecessor of Comet
Encke - a large comet which broke up, one piece becoming the comet.,
another generating the meteors. This year the shower is probably best
seen before the Moon rises at midnight. In late October and
early November, when both the S & N Taurids are active, there is
sometimes a big increase in the number of fireballs seen. Maybe not
this year but still worth looking. November Orionids: active Nov 14th to Dec 6th, peak 28th. ZHR 3. The
Moon sets just before 2am on 28th, so the best time to see them is
between then and around 6am, when the sky begins to brighten. They are
debris from comet C1917F1(Mellish). The radiant of these is
only a few degrees East of that of the N Taurids but it should be easy
to distinguish between meteors from the 2 showers as the Orionids are
much faster moving. Alpha Monocerids: active Nov 13th to Dec 2nd, peak 21st, ZHR 3 -5. This
shower is mainly known for its occasional very short spectacular
outbursts - the last, in 1995, saw about 35 meteors in 5 minutes. The
radiant is very low from our latitude, so the actual number seen is
likely to be fewer than 3. And finally - on the
night of 30th Nov/1st Dec we could have a shower that doesn't even have
a name. The Earth is expected to pass through debris from Comet
46P/Wirtanen, producing some fairly slow moving meteors. The radiant is
in Pisces - and that's all I could find out about that one. Comets There are still a few faint fuzzy blobs around, none naked eye, unfortunately. 2017/01
(ASSASN) moves through Camelopardalis and Cepheus towards Polaris. Best
seen in the middle of the month, when it will be about 10 degrees above
Polaris at midnight. 24P Schaumasse and 62P/Tsuchinan
are both in Leo, moving into Virgo, following very similar paths, with
62P about 2 weeks behind. On 3rd, 24P/Schaumasse passes just
south of the Triplet Galaxy cluster but the Moon will interfere.
24P/Tsuchinan passes between M96 and M105 on the morning of 11th. A very good site for details of all visible comets, including magnitude and exact position on any night, is https://in-the-sky.org/data/comets.php |
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