Night sky notes for October 2016 Geoff Mitchell
The October night sky now sees the autumn constellations prominent early evening and heralds some familiar winter constellations rising by late evening and contains many fine objects to view with both binocular and small telescopes.
The constellations of Cygnus, Lyra and Aquila can be seen slipping westward early evening; these are noted for the bright stars of Deneb, Vega and Altair respectively forming the `Summer Triangle ` asterism.
The Milky Way stretches from Perseus rising in the east, through the `W` shaped constellation of Cassiopeia high in the north east and along the cross shaped constellation of Cygnus. This faint band of stars best seen on dark moonless evenings continues down through the obscure constellation of Scutum and on in the direction of the centre of the Milky Way (not visible from the UK) low on the horizon. Over head the particularly rich star fields running through Cygnus show the spiral arm of our galaxy and some of the obscuring dust in the form of the dark banding of the Cygnus Rift – Binoculars show these star fields well.
Auriga has the bright star Capella and can be seen low in the north east early evening, Capella is circumpolar from UK latitudes and so is always visible.
In the east the constellation of Pegasus, noted for its `Square ` shape and the adjacent constellation of Andromeda noted for The Andromeda Galaxy (M31) , visible to the unaided eye as a faint fuzzy patch on moonless evening can now be seen mid evening . The Square of Pegasus is a useful sign post constellation and also is a good test for sky conditions, (how many faint stars you see within the square is indicates just how good your seeing conditions are). Follow the two end stars (Scheat and Markab) down to find the star Fomalhaut in the constellation of Pisces Australis (The Southern Fishes), visible very low on the southern horizon late evening at the end of the month. Another fine globular cluster is M15 in the constellation, best seen telescopically.
In the North West, Ursa Major, The Plough (asterism) or The Great Bear is seen low with its handle or tail parallel to the horizon mid evening. Use the right hand pair of stars Dubhe and Merak (The pointers ) to find the faint pole star Polaris and hence the position of North . Follow the curve of Ursa Major’s tail to the orange star Arcturus in the constellation Bootes (The Herdsman) low in the west. To the east of Bootes find the `horse shoe ` shaped constellation of Corona Borealis (Northern Crown) and the `Keystone asterism ` in the constellation of Hercules also noted for the globular cluster M13 containing around 750,000 stars, a good view with modest telescopes.
Uranus in the constellation of Pisces and Neptune in the constellation of Aquarius are now both evening objects that can be located using binoculars and a suitable finder chart. A good starting point is to locate the Square of Pegasus and the ring of stars below the Square known as the `Circlet` in the constellation of Pisces (The Fishes), then star hop using the finder chart. Uranus and Neptune are notable due to the blue and green colour, Telescopes show a tiny disc rather than the sharp pinpoints of stars in the field of view. Saturn sets in twilight by late October. Venus may be glimpsed in evening twilight with Saturn, conjunction October 26th. Mars eludes the twilight, moving eastward throughout the month in the constellation of Sagittarius, but is now receding, so presents a small orange disk when viewed telescopically.
In the east mid evening the seven sisters’ (Pleiades, M45) star cluster and constellation Taurus heralds the autumn skies. It is worth noting just what difference the change to GMT (UT) on Sunday 30th October makes on the night skies at the end of the month. The Hyades star cluster makes the characteristic `V` shaped asterism in the constellation of Taurus and noted for the bright, red foreground star Aldebaren , which now rises by early evening. On October 18th, the almost full moon passes close to the Hyades open star cluster.
Jupiter rises in dawn twilight and is in conjunction with the waning crescent moon on October 28th. Jupiter will feature more in the spring skies. The Moon is at its furthest from Earth (Apogee) on Oct 31st (406,662 km).
The Orionid meteor showers, parent comet periodic Comet 1P / Halley, have low rates peaking late October.
Planets in October 2016
Mercury is poorly placed low in dawn twilight during early October with superior conjunction on October 27th
Venus shines brightly low in evening twilight skies; the phase reduces to 85% by late October.
Mars is visible very low in the south/ south west in the constellation Sagittarius in twilight skies
Jupiter rises in dawn twilight low in the east. Conjunction with Mercury (Oct 11th) and the Moon (Oct 28th)
Saturn is a evening twilight object in October and has conjunction with the Sun in mid December
Uranus is visible mid evening in the constellation of Pisces. (Binocular / Telescope required). See notes.
Neptune in Aquarius visible early evening (Binocular / Telescope required). The constellation of Aquarius is positioned low in the south east by mid evening. (See notes)
Moons phases in October 2016
New Moon Oct 1st / Oct 30th Moonless, best time for deep sky observing and Comets .
First Quarter Oct 9th Best days to see shadow details in lunar craters (early evening)
Full Moon Oct 16th Best days to see bright ray craters like Copernicus / Tycho.
Last Quarter Oct 22nd Moon visible in daytime skies. Do not look directly at the Sun.
Note – Clocks change to GMT (i.e. go back 1 hour), Sunday October 30th 2016.
GMT is the same as UT (Universal Time, Greenwich Mean Time beginning at midnight)
Orionids range October 16th to 30th, maxima 21st to 24th – Fast meteors with persistent trails, quite favourable.
Taurids range October 20th to November 30th – Maxima Nov 5th /12th slow meteors, some bright events.
Draconids maxima October 9th, parent comet Giacobini- Zinner, period 6.6 years (no activity listed for 2016)
The Highlights of the Month
October skies, Milky Way visible high over head on moonless evenings in darker skies.
Uranus and Neptune, binocular objects to find using suitable finder charts (see notes)
M31 the Andromeda Galaxy is visible on moonless evenings, best seen in binoculars, low magnification.
Double cluster, on the Perseus /Cassiopeia border, nice pair of star clusters, binocular, medium magnification.
Albireo, the star Beta Cygnii is a nice blue/ yellow double star seen telescopically, moderate magnification.
Dwarf planet Ceres at opposition October 21st in the constellation of Cetus (The Whale) – Binocular / Telescopic
More detailed sky notes and LAS Newsletters , Finder charts are available to LAS members via the Members` page on the LAS Website www.lutonastrolink.org.uk
Use the corner stars of the Square of Pegasus to point (roughly) to Uranus and then use the finder charts and a pair of binoculars to find the `blue` coloured star that in fact is the planet Uranus.
Waxing crescent Moon visibility . Caution. Do NOT look at the Sun directly with or without optical aid. A thin 1.7 day old , 3% waxing crescent moon is visible after sunset on October 2nd from around 18:50pm to moonset at 20:28 BST. Planet Venus in twilight lies to the east of the crescent Moon tonight. On October 3rd the 7% crescent Moon lies close to Venus, moon set is 20:38 BST
Note the dimly lit part visible by Earthshine is readily seen with binoculars or small telescope. Only look for the crescent Moon after the sun has completely set.
More detailed finder charts and newsletters are available to LAS members on the member’s page