How to Locate Andromeda Galaxy in the Night Sky?

Andromeda is our nearest neighbor at just 2.5 million light years distance from our milky way! At an apparent magnitude of 3.4, the Andromeda Galaxy is one of the brightest Messier objects. The galaxy can be made out by naked eye on a clear night but a pair of binoculars gets the job done quite easily. Nowadays in Pakistan, it can be easily seen throughout the night. 

 

To find the Andromeda, first you will have to locate few constellations. This is quite easy once you know your way around in a night sky. Here are few images to help you:

Constellations are demarcated further. Blue is the Pegasus constellation, Green is the Andromeda constellation and White is the Cassiopeia constellation. The red circle shows the position of the galaxy:

 

The galaxy is seen in the Andromeda constellation (although the constellation stars themselves have nothing to do with the galaxy, they are named so because of their apparent proximity to the galaxy from the vantage point of a viewer on Earth).

 

To locate Andromeda galaxy, you can use one of the following two methods:

1) Through the Great Square of Pegasus (Winged Horse):

The square is easily visible in the autumn sky in Northern Hemisphere. Three stars of this square are members of the Pegasus constellation α-Pegasi [Markab (in Arabic means saddle of horse)], β-Pegasi [Scheat (from Arabic Al-Said)], γ-Pegasi [Algenib]. The fourth corner is formed by α-Andromedae [Alpheratz]. 

This α-And is the brightest star of the Andromeda constellation. The square of Pegasus is demarcated with blue in the above image. The next star which is numbered 1 (with white background) is δ-Andromedae. The star number 2 is β-Andromedae [Mirach] while the third star is γ-Andromedae [Almaak].

2) Through the Cassiopeia (Queen) constellation:

If you use Cassiopeia as your guide, look for the characteristic M or W shaped constellation; focus on the first/brightest triangle of the M. Now trace your way towards the pointed end of the triangle and you will hit a bright star, this will be the β-Andromedae [Mirach]. See the above image, the purple arrow is pointing from the red Cassiopeia triangle towards Mirach.

Once you have found the Andromeda constellation and traced your eye to the β-Andromedae star, the job is almost done. Move your eyes from β-Andromedae [Mirach] towards Cassiopeia and you will see a magnitude 3.85 star, the μ-Andromedae (numbered 1 with yellow background in the above image). The next star is v-Andromedae (numbered 2 with yellow background in the above image) of magnitude 4.5. Just besides the v-Andromedae, you will see a cloud like object, this is M-31, the Andromeda galaxy. See the red circle in the following image:

 

If you look through binoculars you will make out that the centre of the cloud is brighter than the peripheries and you can also see that the galaxy is a flattened disk and not a sphere!

We hope you enjoy seeing the Past, as you will be looking at 2.5 million years old image of Andromeda!! Who knows what has happened since then :-)

Andromeda Galaxy is a Spiral Galaxy