The night sky in October 2019

posted 2 Oct 2019, 05:23 by Pete Collins   [ updated 2 Oct 2019, 09:30 ]
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.

The rest are far away in the Kuiper Belt, therefore very faint and only suitable targets for the most experienced astrophotographers.

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.

Epsilon Geminids:  active 14th to 27th, peak around midnight on the night of 18th/19th, ZHR 3, best seen just before dawn.  Again there will be interference from the Moon, rising at 20.38 on 18th.
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