EYES ON THE NIGHT SKY: SEPTEMBER 2020
Welcome to the September edition of Eyes on the Night Sky, where we will present to you the most interesting night sky targets. September is a great month for planets, Milky Way gazing and picking out fainter objects due to the longer nights. We will also provide a whistle stop tour of deep sky objects you can see with the unaided eye.
The Autumn Equinox falls on 22nd September, marking the end of summer. This month, look out for the Zodiacal Light is it makes an appearance in our dawn skies. During the last two weeks of September look eastwards at around 3.30am for a faint cone of light, caused by the Sun lighting remnant dust in the Solar System.
The full Moon falls on 2nd September; this month it is aptly named the ‘Corn Moon’, the time of year when farmers bring in their harvest of corn. Normally, the September Full Moon should be called the Harvest Moon, but because of the Autumn Equinox, which occurs on the 22nd of the month, the full Moon in early October is the Harvest Moon, due to it being closer to the Autumn Equinox.
The New Moon is on 17th September, providing a great opportunity to spot the Milky Way.
Mars increases in brightness this month as it reaches opposition in October. On 6th September, there will be a stunning conjunction, where Mars will be an astonishing degree or less distance from the waning gibbous Moon. Look to the southwest at around 5.45am. It will be a spectacular sight through binoculars so set your alarm and have them to hand! In areas of Southern Europe, Mars will be occulted by the Moon (Mars will pass behind the Moon).
Venus is the brightest object in the morning sky in September, rising between 1am and 2am throughout the month. There will be a lovely conjunction on 14th September, where the waxing crescent Moon will only be 4° apart from the planet. Look in the eastern sky about half an hour before sunrise and you will see Earthshine on the Moon.
This image was taken over a small town. Even a short drive from populated areas might enable you to spot unaided
If you are able to access a dark sky during September, why not learn about what deep sky treasures you can see with the unaided eye? Here are five to look out for – get to know where they are and impress your friends! It’s amazing to think we can see such distant objects with our eyes but with telescopes or binoculars, they provide a great starting point for studying them in more detail.
You may be able to find this in a rural/suburban sky. This object, comprising two open star clusters NGC 869 and NGC 884, is in the constellation of Perseus.
Look for a ‘W’ shaped constellation called Cassiopeia and try to find a fuzzy patch of light directly below the left hand side of the ‘W’.
M11 Wild Duck Cluster
This cluster might be a bit of a challenge to find, so find a dark sky, away from population centres. Nestled near the Milky Way, it can be found by looking for the three starred- head of Aquila, the brightest star being Altair. Follow the body of this Eagle constellation down to its tail and the very faint cluster lies in the four o clock position. If you are able to spot this, congratulate yourself, as it’s the farthest object that can be seen with the unaided eye!
This spiral galaxy is named after the constellation nearby and can be seen in a rural/suburban sky. Find the large square of Pegasus, high in the south-eastern sky and count two stars to the left from the top left hand corner star Alpheratz. Count another two fainter stars up and you may find a faint, oval patch of light. Andromeda Galaxy is our cosmic neighbour and the largest galaxy in our galactic neighbourhood, comprising 400,000 stars.
Mizar and Alchor
Serving as an ancient eye test, these binary stars in Ursa Major are always fun to spot. Look for the ‘pan handle’ that comprises the constellation of Ursa Major – the second star is Mizar. Look for a smaller star situated very close by, at the 11 o clock position. This is Alchor. There are five stars that gravitationally interact in this system. Most people can spot this double in a dark sky.
This photograph shows Mizar and Alchor binary system in Ursa Major.
M45 – Pleiades Star Cluster
Another one for rural/suburban skies. This stunning open cluster in the constellation of Taurus can be seen high in the sky around midnight. Face eastwards and look for the bright star Aldebaran – above it you will see a tight cluster of stars. Many people can see six stars in Pleiades but a try to use averted vision to see you can spot more. Children with their sharp eyesight can often see up to seven.
Can you see the constellation of Cassiopeia in this image? Clue: It's in the centre of the photo, just above the trees
This Greek myth tells the story of Cassiopeia who was a queen. Full of pride, she thought she was more beautiful than the sea nymphs, which angered Poseidon, the god of the sea. He sent Cetus, the sea monster, who wreaked havoc in her kingdom.
Cassiopeia tried to appease the sea monster by offering her daughter, Andromeda, binding her to a rock by the sea. Andromeda was about to be devoured by Cetus when Perseus came to her rescue. The gods honoured the rescue by placing her in the stars but Poseidon punished Cassiopeia for her evil deeds by binding her to a chair so that as the year progressed, she would revolve in the sky, sometimes being upside down!