EYES ON THE NIGHT SKY: OCTOBER 2018
Welcome to Eyes on the Night Sky for October. Astronomy season is now in full swing, with so many night sky treasures to be found. This month, try to find the farthest solar system planet, view a conjunction, discover a stunning star cluster and more!
Planetwise, there are only a few that can be studied this month – for example, Mercury will be lost in twilight as it sets only half an hour after the Sun. Venus will also be not visible in the evenings for the rest of 2018 as it will be in inferior conjunction - the planet will lie in a direct line between the Earth and the Sun on 26th October and will be at zero degrees, which means the planet will have the same right ascension as the Sun.
You can still catch Mars before it sets at midnight during the month – it has dominated the night sky this year, blazing as an orange jewel in contrast to relative whiteness of the stars. On 18th October, around 7pm, there will be a conjunction with the waxing gibbous Moon of around 3° separation – watch for Mars to emerge in the twilight.
Jupiter and Saturn will only be visible for up to a couple of hours after sunset – look out for them low on the SSW horizon, Jupiter setting around 6:50pm and Saturn a couple of hours afterwards.
With Uranus at opposition (directly opposite the sun), it is the closest to earth and should be visible all night. Its location is in the constellation of Pisces.
Neptune sets around 2am towards the end of the month and can be seen through 10 x 50 binoculars. Find the constellation of Aquarius and look for the left arm – the planet is nearly in the ‘elbow’ of this constellation, between the stars Hydor and Lambda Aquari. The planet appears as a small, blue/green disk, which becomes more apparent through a small telescope. Even though it is very small, it is exciting to be gazing upon the furthest planet away from the Sun, at a staggering 4.5 billion km away!
The New Moon is on 9th October and the Full Moon falls on 24th October
The Zodiacal light can be observed this time of year – watch for it between 8th to 22nd October, around an hour before dawn. Remember, this rare phenomenon should be sought during times when the moon isn’t present.
This incredibly beautiful open star cluster, 444 light years away, is visible anywhere on earth and looks like a very small version of the Big Dipper with the unaided eye. This time of year, it heralds the rising of the Winter Constellations such as Orion but is a worthy target to study. Anyone with good eyesight in good sky conditions can spot up to 14 stars with the unaided eye. This cluster, also known as the Seven Sisters or Messier 45 contains young, hot blue stars and in photographs, appears to have a mist surrounding them, which is an interstellar cloud of dust and gas that the cluster has drifted into. It’s a fine example of a star cluster associated with reflection nebula.
In a dark sky through telescopes larger than 12” in aperture, the nebulous material can almost be spotted as the stars take on a diffuse appearance through the eyepiece. Through binoculars, it provide a very pleasing wide field target of bright stars - with averted vision you might even be able to spot slight hints of nebulosity around the star Merope.
Cat's Eye Nebula
This relatively bright planetary nebula in the constellation of Draco can be seen through 10x50 binoculars and small telescopes. Discovered by William Herschel in 1786, this nebula lies 3330 light years from earth and was formed 1000 years ago.
It should be easy to discern its fuzzy, vivid green colour from the surrounding stars and best seen in telescopes of 8 inches of aperture and upwards. In darker skies, you would be able to see a bluish oblong disk and tease a little bit of detail out in the nebula, using averted vision. The Cat’s Eye nebula is one of the most structurally complex ever discovered.
This planetary nebula, in the little constellation of Sagitta, is more fondly known as the Apple Core Nebula due to its shape resembling an eaten piece of fruit! It’s also known as Messier 27. It’s a lovely, bright object, discernible in 10x50 binoculars, situated some 1,360 light years from Earth. The nebula looks good in telescopes of 8” and upwards and the apple core shape is easily spotted. You might see a greenish tinge to this nebula, unlike the image above, which has been processed. Through larger telescopes of 12” onwards, you might be able to tease out more filamentary detail.
To find the constellation of Sagitta, look for the Northern Cross which makes up the constellation of Cygnus and look for a two pronged ‘stick’ asterism at the 7 o’ clock position. Whilst you are in the area, try to spot a bonus object, globular cluster M71, which can be found with a telescope.
Hope you have clear skies and remember that the clocks go back one hour on 28th October at 2am (BST).