How to find the Andromeda Galaxy (M31) the brightest galaxy in the night sky

When people start with astronomy, they often want to see the planets and the moon and then, after a while, what they want to observe something more challenging, but still impressive. They often conclude that they want to see galaxies and what better galaxy to observe first than Andromeda galaxy?

Also known as Messier 31 (M31) the Andromeda Galaxy is visible to the naked eye as faint smudge in areas of no light pollution. It is due to being visible with the naked eye that the galaxy was first recorded as far back as the year 964, by the Persian astronomer Abd al-Rahman al-Sufi.

One of the reasons that the Andromeda Galaxy is visible with the naked eye is that it is the largest close by galaxy to us. In fact, it is heading towards us at 100 to 140 kilometres per second.

Due to all of this it is not surprising that the Andromeda Galaxy is the brightest galaxy in the night sky with a magnitude of 4.5.

Click to enlarge Andromeda Galaxy star chart

Where is M31?

To find the Andromeda Galaxy first you need to find the constellation Cassiopeia which is a great sign post consolation and one of my favourite constellations in the night sky looking like a strange but obvious 'W'. Next find the largest point to the 'W' and head down I recommend at this point using a low powered eyepiece such as a 32mm Plossl eyepiece to locate the galaxy.

It is best to observe this galaxy during the winter months. When the dark skies will help bring out the Andromeda’s details and make it easier to spot Andromeda’s satellite galaxies.

If you want more of a challenge and would like to see objects within another galaxy then the Northern Pinwheel Galaxy (M101) is something you might be interested in.

To see what the galaxy should look like through the eyepiece and for some more detailed sky maps please watch the episode below.



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