SKY Notes for September by North Wales astronomy lecturer Brian Woosnam.

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 7.50am BST on 23rd (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 a little west of south.

The Moon

Last quarter 6th First quarter 22nd Full moon 29th

The planets

Venus is in Cancer visible in the early morning sky and very bright. Mars is too close to the Sun to be seen in September.

Mercury is in the early morning sky rising around 5am and to the lower left of Venus. It moves to the maximum distance from the Sun on the 22nd.

Jupiter is in Aries and begins retrograde motion in the first week of the month rising around 9pm. Saturn is in Aquarius and above the horizon all night long.

The Constellations

21.00 – 23.00 BST in the East

Perseus (Open Cluster M34), Aries, Andromeda (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 around midnight and be 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

Monday 4th Jupiter 3.5 degrees south of the moon, with the Pleiades to the left.

Monday 4th is lecture night at the Fron Community Centre Colwyn Bay LL29 8TN 7pm – 9pm. Tonight’s lecture by Brian Woosnam “What is Astronomy? And how to get started”

Tickets are Adults £5.00 children £2.00

Tuesday 5th Uranus will be 3 degrees south of the moon.

Wednesday 6th the planet Mercury is at inferior conjunction.

Monday 11th at dawn Venus will be 11 degrees south of the crescent moon.

Tuesday 12th the moon is at apogee 406,291 km from the Earth.

Wednesday 13th Regulus will be 4 digress south of the moon also Mercury 6 degrees south of the moon.

Saturday 16th Mars is 0.7 degrees south of the moon.

Monday 18th Venus reaches it greatest brilliance as a morning star.

Thursday 22nd the planet Mercury is at greatest elongation.

Saturday 23rd September equinox 7.50am nights become longer than the days as the Sun moves south of the equator.

Wednesday 27th Saturn 2.7 dress north of the moon.

Friday 28th the moon will be at perigee 359,911 km from the earth.

Friday 28th Neptune is 1.4 degrees north of the moon.