Autumn’s advance gathers pace as the Sun heads southwards and after the Autumnal Equinox (the Sun crosses the equator from North to South), which occurs at 20.21pm BST on 22nd (Earth – Sun distance 150128448km) dark skies will set in from mid-evening.

The summer’s bright constellations are however still largely on view. By 21.00 BST Capricornus is on the meridian low to the South. The Summer Triangle stars Deneb, Vega and Altair are still high west of south.

The Moon

Phases First quarter 13th, Full moon 20th and 29th.

The Planets

Mercury and Venus are in the southwest evening sky in Virgo. Venus will be higher than Mercury the brighter of the twoplanets and will improve towards the end of the month. Venus will be visible above the horizon an hour after sunset. Mercury will be a lot lower and only visible for 30 minutes after sunset during the first two weeks then it moves closer to the Sun.

Saturn is an evening object in Capricornus and will be due south at 23.10 BST it will have an altitude of 18 degrees by the last week of the month it will be due south by 21.10BST.

Jupiter will be an object in Capricornus with an altitude of 22 at the start of the month due south at midnight.

Neptune is an object in Aquarius and is south at 1am being a lot further out in our solar system 4.5 billion kilometres from the Sun taking 164.8 years to orbit the Sun you will need a telescope of 200mm or larger. A magnification of 200x will show its disc Neptune reaches opposition on the 14th but as its so far away from the Earth it will not make a lot of difference.

The Constellations

21.00 – 23.00 BST in the East - Perseus (Open Cluster M34), Aries, Andomeda (Spiral Galaxy M31) and Pisces. 21.00 – 23.00 BST in the South - Pegasus, Cassiopeia, Cygnus, Vulpecula (Dumbbell planetary nebula M27) Lyra (Ring planetary nebula M57) and Aquarius. 21.00 – 23.00 BST in the West Hercules (Globular Clusters M13 & M92), Draco, Corona Borealis and Bootes.

23.00 – 01.00 in the East Taurus (M45), Auriga, Orion will rise midnight, well placed by 2am to see the great nebula M42 just below the belt.

Deep sky objects: NGC7662, M52 and NGC40

Events during the month

On September 1st look at Jupiter from 2.33Bst and watch the moon Callisto transiting Jupiter’s disc sadly Jupiter will set before the transit ends.

On September 2nd the 24% waning crescent moon occults +3.0 Mebsuta Epsilon from 1.12 Bst until 2.04 Bst these times are for the centre of the UK so check the time for you location using Stellarium.

On September 3rd the 16% waning crescent moon occults +3.6 Kappa Geminorum from 3.41Bst until 4.38 Bst these times are for the centre of the UK so again check the time for you location using Stellarium both stars are in Gemini.

On September 4th the 9% waning crescent moon will be 2.6 degrees from Beehive Cluster M44 at 4.10 Bst,

On September 5th look at Jupiter and watch two of the moons cast a shadow as they transit Jupiter. Europa starts its transit at 23.12 Bst and its shadow should be visible from 00.04 Bst Ganymede starts its transit at 2.03 Bst and its shadow should be visible from 3.47 Bst.

September 7th look low down on the western horizon after sunset and see the 1% lit waxing crescent moon it will set 35 mins after the Sun.

September 9th look to the southwestern horizon after sunset and see Venus slighty higher up to the left of the 9% waxing crescent moon.

On September 11th Asteriod 2 Pallas reaches opposition in Pisces. you should be able to spot with a pair of 10x50mm binoculars.

On September 13th if you have a telescope look at the Moon around 21.30 Bst and see the Clair obscur effort known as Lunar X and Lunar V next to the terminator.

On September 14th Mercury reaches greatest eastern elongation separated by the Sun by 26.8 in the sky Mercury will set 20 mins after the Sun.

On September 17th at 22.30 bst the 89% lit gibbous Moon will near Jupiter and Saturn. A shadow transit of moon Callisto on Jupiter starts at 23.43 Bst .

September 20th’s full moon is the closet to Earth in the Nothern Hemisphere and will be the harvest moon. On September 22nd the autumn equinox the Sun crosses from the North to South.

On September 29th look at the moon to see the Clair obscur effect known as Gruithuisen’s Lunar City north of crater Schroter W.

Sky Notes courtesy of Brian Woosnam of North Wales Astronomy Society.