by Anne Holt Sunrise 1st: 07.09 31st: 07.05 Sunset 1st: 18.46 31st: 16.39 Astronomical darkness 1st: 20.45 to 05.14 31st: 18.37 to 05.08 British
Summer Time ends on Sunday 27th at 02.00, and for the next 5 months we
have proper time, with the Sun at its highest point in the sky at 12
noon. Full Moon; 13th at 22.07 New Moon: 28th at 03.38 October's
full Moon is known as the Hunters' Moon, because this was the time for
hunting animals then preserving the meat to last over the winter. Other
names are the Dying Grass Moon and the sometimes confusing Blood Moon
or Sanguine Moon. Lunar apogee: 10th at 18.30 (405901km) Lunar perigee: 26th at 10.42 (361314km) Highlights Still
not much to shout about despite the longer nights. On 1st we have eight
and a half hours of astro darkness increasing to ten and a half hours
on 31st, when it begins at 18.37 (GMT). The naked eye planets are all
very low and the one major meteor shower will be adversely affected by moonlight. However we have several minor showers and a chance of bright
fireballs. And, by month end, the best constellation of all, Orion, is
above the horizon by midnight. 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 -0.2 An
evening object but hardly visible this month. On 1st it sets at 19.07,
only 20 minutes after the Sun. It's at aphelion (furthest point in its
orbit from the Sun) on 3rd, when it is at a distance of 0.47AU. It
moves into Libra on 10th and reaches greatest eastern elongation on
20th, when the angular separation is 24.6 degrees but, because of the
very shallow angle of the ecliptic at this time, it is still very low,
barely on the horizon as the sky darkens. On 31st it sets at 16.58,
has faded to mag 0.4 and is 2 degrees below the horizon at dusk. Venus: in Virgo, mag -3.9 Another
evening object very low in the sky but, because it is so bright, might
be visible in the evening twilight. On 1st it is on the horizon as the
sky darkens, setting at 19.10. It appears to move away from the Sun
during the month but remains very low. It moves into Libra on 16th and
on 23rd the thin crescent Moon is just under 3 degrees below the
planet. On 30th Mercury and Venus are very close with Venus 2.6 degrees
to the north, but very difficult to see as they are so low. On 31st it is 2 degrees above the horizon at dusk and
sets at 17.19.Mars: in Virgo, mag 1.8 Now
a morning object, starting the month very close to the Sun. On 1st it
rises an hour before the Sun but appears only 9 degrees from it. The
separation increases during the month, on 13th it is 2 degrees above the
horizon at dawn. On 31st it rises 2 hours before the Sun and gets to 7
degrees in the east before the sky begins to brighten. Jupiter: in Ophiuchus, mag -2.1 Now
very low as the sky darkens. On 1st it should be visible for a short
time soon after 7pm when it will be 11 degrees above the southern horizon. On 3rd the
30% Moon passes about 1.8 degrees NW of the planet. They are also close
on 31st, separated by just over one degree in daylight and visible,
slightly further apart, at around 18.00 at 9 degrees above the SW
horizon. On this day Jupiter sets at 18.44 and will have faded to mag
-1.9. Saturn: in Sagittarius, mag 0.5 Best
seen in early October, on 1st it should be visible, 13 degrees above
the southern horizon at around 19.30, setting at 23.16. On 5th the
planet and the first quarter Moon are only one degree apart at 22.30,
but very low. Saturn sets at 23.01 on this day. On 31st it is at 13
degrees in the south as the sky darkens around 17.30, setting at 20.24. Uranus: in Aries, mag 5.7 The
best positioned of the planets. On 1st it rises at 19.24 and should be
visible from 10pm, when it is 21 degrees above the eastern horizon,
culminating at 02.44 when it reaches 49 degrees in the south. On 15th
at 1am the Moon passes 5 degrees south of the planet. It is at
opposition on 28th when it is at its highest point at 23.49. On 31st it
reaches 48 degrees in the south at 23.37, setting at 06.54 a few
minutes before sunrise. While it is theoretically a naked eye object it
isn't easy, a very dark sky site and good eyesight are needed. For all
others, binoculars are necessary, or a scope to show the small blue/green
disc. Neptune: in Aquarius, mag 7.8 Still
quite high for most of the night, especially in early October. On 1st
it culminates, 30 degrees in the south, at 23.39, setting soon after
5am. On 10th, around midnight, the Moon passes about 4.5 degrees to the
south. On 31st it culminates at 20.39, slightly lower at 29 degrees,
setting at 02.11. It might be possible to spot it through binoculars if
you're at a dark sky site and know exactly where to look. A reasonable
sized amateur scope should show the small blue disc. Dwarf Planets Ceres: in Ophiuchus, mag 9.1. The
only one of the 5 which orbits in the (relatively) nearby asteroid belt
is not well placed at the moment. On 1st it is only 11 degrees above
the horizon as the sky darkens, setting at 20.51. On 31st it is at 10
degrees at dusk and sets at 18.24. Pluto: in Sagittarius, mag 14.7. Too
low for imaging reaching a maximum altitude of 14 degrees. Because it
appears to move so slowly round the ecliptic - it takes 248 years to
orbit the Sun - it will be about 20 years before its position begins to
improve, and a further 20 before it gets high enough to be succesfully
imaged from our latitude. Makemake: in Coma Berenices, mag 17.1. Still
very low, on 1st it rises less than 3 hours before the Sun and sets
almost 4 hours after it. However it is very low in both the dawn and
dusk sky for most of the month. On 31st it rises at 02.15 and reaches
26 degrees above the eastern horizon before the sky brightens. Haumea: in Bootes, mag 17.4 On
1st it is 18 degrees above the horizon at dusk, setting at 22.18. It
is at Solar conjunction, on the opposite side of the Sun to the Earth,
on 20th. Like Makemake last month, because its orbit is highly inclined
to the ecliptic, it passes about 29 degrees above the Sun. On 31st
it rises at 04.17 and sets at 19.21 but doesn't get higher than 10
degrees above the horizon. Eris: in Cetus, mag 18.8 The
most distant dwarf planet, way out in the Kuiper belt, takes nearly 558
years to orbit the Sun. It's also by far the faintest, so very
difficult to image even by the best amateurs, even though it is
currently reasonably high. On 1st it culminates at 02.17, at 34
degrees, it reaches opposition on 17th, when it culminates at 01.13, and
on 31st reaches that altitude at 23.14. A couple of asteroids are at opposition in October: 13th:
29 Amphitrite, in Pisces, mag 8.7. This passes only 1.41AU from Earth
and reaches 48 degrees in the south at 00.50. It should be visible in a
moderate sized scope. The bad news is that the full Moon is also in
Pisces on this day. 26th; 9 Metis (not
to be confused with the innermost moon of Jupiter, which has the same
name) in Cetus, mag 8.6, slightly closer at 1.16AU. and culminates at
01.00, at 42 degrees in the south. You may have heard about an asteroid which will pass 'very close'
to Earth on Thursday 3rd. It's about 19 metres across but don't worry -
2019 SP3 will pass us at a distance of 231,690 miles, which is 97% of
the Earth - Moon distance. I think we're quite safe. Comets There
are quite a few around, several circumpolar or almost so, which are
above the horizon for most of the night. However there is nothing very
bright, or likely to be even within range of binoculars (Probably. Estimates of magnitude vary considerably). However comets are very
unpredictable so you never know. C/2017 T2
(PANSTARRS) in Taurus, mag around 8 or 9. Visible in the late evening.
On 1st it rises at 20.59 and reaches its highest point of 63 degrees
just before dawn. It moves northwards during the month, crossing the
border into Auriga on 7th. On the nights of 27th to 30th it passes
about 1 degree to the east of open cluster M36. On 31st it culminates
at 03.05, higher at 71 degrees. C/2018 W2
(Africano) in Pisces, mag around 8. On 1st it culminates, 39 degrees above the southern horizon, at 23.56. Moving southwards, into Aquarius
on 4th then getting too low to be visible. Goes into Piscis Austrinis
on 15th and by month end is in the southern constellation of Grus, the
crane and is below the horizon at all times. C/2018
N2 (ASSASSN) in Triangulum, mag 11. High in the sky during the hours
of darkness throughout October. Culminates on 1st at 02.25 at 68 degrees
in the south. It moves into Andromeda on 13th and is circumpolar from
17th, when it reaches 72 degrees above the southern horizon at 00.47.
On 31st it gets to 74 degrees at 22.15. 260P/McNaught
in Perseus, mag 11.6. Circumpolar so also above the horizon all night.
On 1st it reaches 74 degrees in the south at 03.20 and is still 62
degrees above the horizon at dawn. On 31st, faded to around mag 12, it
is almost overhead at midnight. 168P/Hergenrother,
in Auriga, mag 11.8. Another faint but well positioned comet,
circumpolar throughout October. On 1st it reaches 77 degrees in the
east just before dawn. It moves into Lynx on 6th, when it will be a
couple of degrees higher as the sky brightens. On 31st its highest
point will be at 05.03, 87 degrees above the northern horizon - or, if
you prefer, 93 degrees in the south. Wouldn't normally mention this as it is so faint but there has been quite a bit of publicity about it. C/2019
Q4 (Borisov) in Leo, mag 18. The newly discovered comet is the first
to be shown to originate outside our Solar System. Too faint to be
within range of even the best amateur astrophotographers. On 1st it
rises at 01.42, on 31st at 02.06. Recommended websites for more information and exact positions of all Solar System objects. And for comets Meteor Showers One major shower this month. Orionids,
active oct 2nd to Nov 7th, peak on the night of 21st/22nd, ZHR 20 - in
ideal conditions. From our light polluted skies and with the radiant
being quite low, we'll be lucky to see more than a quarter of that
number. This shower often has smaller peaks on the nights before
and after the maximum. These fast moving meteors, often leaving
trails, are caused when the Earth passes through dust clouds left by
comet 1P/Halley. The radiant rises at 10pm and the shower is usually
said to be best seen about 5am. However this year the Moon rises at
23.28 on 21st so will interfere. Fair to middling shower: Draconids,
active 6th to 10th, peak on the night of 9th/10th ZHR 10. Very slow
moving meteors, parent comet 21P/Giacobini- Zinner. On the morning of
10th the 92% Moon sets just before 03.15. There are several minor showers: Camelopardalids:
Very short lived shower, active 5th to 6th, peak on the morning of 6th,
ZHR could be as high as 5, more likely to be 1 or even none. However,
this shower has been known to produce very short outbursts. The Moon
sets just before 11pm on 5th. Southern
Taurids: active Sept 10th to Nov 20th, peak 10th, ZHR 5. This shower
also sometimes produces minor peaks at other times. They are very
bright, slow moving meteors making them ideal photographic subjects.
These and the associated Northern Taurids are thought to have originally
been a single shower which split into 2 separate streams several
thousand years ago. Parent comet is a precursor of
2P/Encke. The Taurid showers are often rich in fireballs, so the later
part of October, when both are active, is a good time to see
these. Delta Aurigids: active 10th to 18th,
peak around 22.00 BST on 11th, ZHR 2. Best seen around 2am but the
almost full Moon will interfere, not setting until 04.21. |