How to Find Andromeda Galaxy in the Night Sky

You’d be forgiven for wondering why Andromeda Galaxy is so difficult to find!

After all…

M31, as it’s also known, is the brightest of the Messier galaxies.

A view of Andromeda galaxy
The Andromeda Galaxy (source)

How is it so difficult to find with a telescope, then?

Is it a result of light pollution, or are you simply in the wrong place at the wrong time? Are you just looking at the wrong section of the sky, perhaps?

Since Andromeda is one of the first deep sky objects an amateur will try to find, being unable to do so can be frustrating.

We at Love the Night Sky want you to can take in the glorious sight of M31. Whether that’s through your beginner’s telescope, or even binoculars (yes, Andromeda is bright enough to see with binoculars), finding it will bring you a glow of pride and awe!

Read on to discover how to find the Andromeda Galaxy.

What is the Andromeda Galaxy?

The Andromeda Galaxy is a member of the Local Group of galaxies, the same group that our own Milky Way galaxy is in.

Although it’s 2.5 million light-years away from us, it’s so bright – shining at magnitude 3.3 – that you can see Andromeda with the unaided eye from a dark enough site.

When it comes to urban areas, however, light pollution means you’ll only see M31 through a telescope, even then, you’ll only see its bright core.

Andromeda has four dwarf galaxies nearby, two of which are M32 and M110. You can see them both as large, bright ‘stars’ on the image at the top of this page. The smaller one above Andromeda is M32, while M110 is larger and below the main galaxy.

These two are the nearest bright elliptical galaxies, while farther away in Cassiopeia are NGC 147 and NGC 185, shown as the two small red dots above M31 on the star map below.

For the rest of this article, we’ll focus on finding the Andromeda Galaxy itself.

Where is the Andromeda Galaxy?

how to find andromeda galaxy in andromeda constellation
The big red oval in the center is the Andromeda galaxy (source)

You won’t be surprised to learn that the Andromeda Galaxy is found in the constellation of Andromeda.

The constellation of Andromeda is best viewed in fall in the Northern Hemisphere, where it can be seen from dusk until dawn.

In late September and early October, M31 rises in the eastern sky. It’s overhead around midnight and still high in the west as it fades into the morning’s dawn glow.

The galaxy itself is well-positioned overhead in the evening throughout winter. A planisphere (Amazon link) will help you find it at the time you’re viewing. If you’ve never used one before click here for our guide to using a planisphere.

You can also try astronomy software such as Stellarium, which is free, or SkySafari 6, which you need to pay for.

When you know which part of the sky to look in, it’s time to begin the hunt.

How do I Find the Andromeda Galaxy (M31) with My Telescope?

One of the hardest things about locating the Andromeda Galaxy for the first time is knowing what to expect when you see it.

How to find Andromeda (M31)
You will not see Andromeda like this! (source)

It sadly will not look like this image, nor many others you’re used to seeing, and it’s nowhere near as bright as the stars nearby.

With the unaided eye, Andromeda is a hazy patch of light in the sky, about as wide as the full moon would be. You may even mistake it for thinking your eyepiece is a bit blurry… a gray smudge on the sky is perhaps the best way to describe it.

When you appreciate better what it will look like, it does become easier to find Andromeda and many other galaxies.

Thankfully, there are a few star-hopping routes you can follow to find the Andromeda Galaxy. The following are the ones we like the best.

Finding M31 With Alpheratz and Mirach

One way that you can find Andromeda is to use the stars Alpheratz (Alpha Andromedae) and Mirach (Beta Andromedae) in the constellation of Andromeda.

Click the image below to enlarge it, and you will see Alpheratz on the corner of the Great Square of Pegasus and Mirach on the upper ‘leg’. Click the image for a full screen version.

Locating Andromeda Galaxy with Alpheratz and Mirach
Finding Andromeda Galaxy with Alpheratz and Mirach (courtesy SkySafari 6)

Use your viewfinder to hop down two stars northeast from Alpheratz to Mirach. When you have Mirach in your sight, move northwest to Mu Andromedae. The Andromeda Galaxy lies the same distance again (about 1.3°) and in the same direction past Mu Andromedae. 

1.3° is close enough that you will be able to see both objects in your viewfinder at the same time. You may even get them both in your eyepiece if you have a wide field of view and low magnification.

Finding the Andromeda Galaxy with Cassiopeia

The image below shows how close Cassiopeia is to M31, see Cass in the bottom right corner. Click it to get a larger version.

Using Cassiopeia to find Andromeda Galaxy
Using Cassiopeia to find Andromeda Galaxy

Cass is perhaps the easiest constellation to find in the night sky after the Big Dipper, which makes it perfect to use for hunting our target. For most of us, it’s also a circumpolar constellation, which means it’s out all night and a reliable sight.

Find the Andromeda galaxy using Cassiopeia by using the ‘V’ shape of the stars Shedar, Caph, and Navi to point the way to Mu Andromedae and Mirach, which you can then use as before to pinpoint M31.

What Andromeda Galaxy Looks Like in a Telescope

While M31 can be seen with the naked eye, it is just an uninteresting haze.

For a more detailed view use a telescope. Any decent telescope (like these) will show some structure in the galaxy. Of course, the more light you gather, the more detail you see. So larger scopes designed for deep space viewing give better results.

One absolute essential to getting a good view of M31 is a dark sky.

If you can, try and get away from light-polluted areas, which will obscure the edges of Andromeda and leave you only able to see its core. Light pollution includes moonlight, so pick an observing time when the moon is below the horizon.

Andromeda in a Small Telescope

In any scope of 4″ and upwards, you’ll see an oval-shaped blur that’s long and thin. With averted vision and patience, you’ll notice the oval is thicker and brighter at its center.

The companion galaxy M32 looks like a too-large star nestled just south of the main galaxy. If your scope will tolerate higher magnification, you may see that M32 is also more oval than circular.

The main galaxy may yield tonal changes in its brightness away from its heart. You may also perceive it to be more circular at its heart and flatter, more linear further out.

It’s a push in a smaller scope, but challenge yourself to see dust lanes against the light regions.

Andromeda in a Large Telescope

If you own a large Dobsonian scope, you’ll be blown away by the sight of Andromeda.

Allow your eyes to adapt to the faint light and, if the night is dark enough, averted vision will help you discover the wider reaches of this mesmerizing vista.

Looking through 8″, 10″, or more, you’ll be able to chase the circuit of ghostly arms of stars surrounding the brighter central core.

Wrapping Up

While M31 is the brightest galaxy visible in the northern hemisphere, it can still be hard to find.

Hopefully, this article will help you locate it in the dark of the night sky. Both methods we’ve shared are proven to work.

If you have any trouble finding the Andromeda galaxy, or just have something to say, feel free to comment below. Happy hunting!

This video explains the methods discussed here more in-depth and with visual aids that you might find helpful.