First Light Guide #1: How to find M31 & M32

Messier 31, the Great Andromeda Galaxy

& Messier 32

A detailed guide to finding / observing two galaxies in Andromeda

First Light Guide 1 graphicFirst Light Guides #1 and #2 are detailed written and video references to finding and observing the galaxies Messier 31 and Messier 32 in the constellation of Andromeda. These guides are ideal for beginners, but many advanced amateur astronomers may find these useful. Note that M31 is sometimes known as The Great Andromeda Galaxy. These guides will help you locate these two galaxies with almost any telescope set up. There is a guide to using a magnified finderscope, red dot finder, or setting circles along written tips on observing M31 and M32.

Visitors who are new to this site may wish to get started here, while more advanced observers can search the First Light Guides by constellation, or by right ascension

Find Messier 31 in the sky

Messier 31 is the closest spiral galaxy to our own Milky Way galaxy. It is just over 2 million light years away, so the photons reaching your eye in a telescope tonight left that galaxy some 2+ million years ago, just before the time of homo erectus. The Andromeda galaxy is on a collision course with our own, and the two will merge in about 4 billion years.

If you have a magnified finderscope on your telescope, start here to find M31. Circle for finderscope shows a 7 degrees field, and stars displayed are to 7.5 magnitude. 

If you have a red dot finder on your telescope, start here to find and observe Messier 31. Stars displayed are to 3.5 magnitude.

If you have a telescope that has an equatorial mount with fairly precise setting circles, you may find this video useful when trying to find Messier 31:

Find Messier 32 in the sky

First Light Guides 2 graphicMessier 32 is an elliptical galaxy also visible near Messier 31. Long thought to be a small satellite galaxy of M31, new studies suggest that M32 may be the remnants of a spiral galaxy that had its outer stars stripped away by the larger M31. Either way, it has a burst of stars forming in the central region; this is why M32 is so bright making it easy for us to see.

To find M32, locate M31 using one of the methods above. Then watch this video below to learn how to locate and observer the dwarf elliptical galaxy M32:

Observing tips:

From darker sky locations, one or both of the galaxies may be visible with a magnified finderscope. If not, take note again in the star hop video where the star Nu Andromedae is; it is a 4.5 magnitude star that should be visible in most any decent finderscope. Nu And is 1.3 degrees from the galaxies, just off the line you moved on from Mirach (Beta And) to Mu And. In a 7 degrees diameter finderscope field of view, place Mu at the edge of the field after moving through it from Mirach; M31 should be nearly centered then. With a red-dot finder, M31 is nearly the same distance from Mu And, as Mu And is from Mirach.

Use VERY low power initially. If you do not see the galaxies, slowly scan the area with the slow motion controls. The movement may help you make out the round or oval shaped glow of the brighter one, Messier 31. Messier 32 will look small and like a fuzzy star, but there are enough other stars in the region that it will be difficult to mistake having the telescope out of focus. Also try using averted vision, or tap the telescope tube lightly to activate the rods in your peripheral vision, which are more sensitive to low lighting levels.

Useful filter(s): Broadband light pollution filter, perhaps, in smaller telescopes. Narrowband may be useful in larger instruments. Note that galaxies emit light in all spectrum, so the only benefit to either filter is to improve perceived contrast by darkening sky background. 

What should I see?

Below is an approximate view of Messier 31 and Messier 32 as seen with a 70mm telescope at 38x magnification, and a 1.4 degree telescopic field of view.  Demonstrates how view would look with objects on the meridian using a refractor telescope and a star diagonal.  Other telescopes or object sky positions may incur a differing view.  Various magnifications, eyepieces, telescope focal lengths and other variables may alter the view compared to this one.  This is a representation only intended to help the observer get some idea what they may see at the eyepiece.  Extreme local light pollution may block the view entirely.

M31 and M32 visual graphic

Details of Messier 31

Type: SA(s)b Spiral Galaxy

Distance: 2.54 million light years, ± 0.11 

Apparent dimensions: 190 × 60 arc minutes

Apparent magnitude: 3.44

Right ascension: 00h 42m 44.3s

Declination: +41 16' 09"

Details of Messier 32

Type: cE2 dwarf elliptical

Distance: 2.49 million light years, ± 0.08

Apparent dimensions: 9 × 7 arc minutes

Apparent magnitude: 8.08

Right ascension: 00h 42m 41.8s

Declination: +40 51' 55"

Because telescopes and observers are all different, here are some alternate sketched/drawn views of Messier 31 and Messier 32:

Simon Rowe, using a 130mm reflector at 36x

Cloudy Nights user neoweb, using 15x70 binoculars

David Finlayson, using various instruments (several sketches)

Looking for other nearby First Light Guide objects? Here's some to consider:

Double star: Eta Cassiopeiae

Open cluster: NGC 457

Double star: 56 Andromedae

Double open cluster: NGC 869 / NGC 884

Variable star: Algol

The constellation: Andromeda

General information about Andromeda, the Chained Princess, where Messier 31 and Messier 32 are located. This will help you know where to find the constellation in the sky and be able to locate and identify its brightest stars.

Name of constellation: Andromeda

Abbreviation: And

Genetive form: Andromedae

Common names: Andromeda, The Chained Princess

Associated asterisms: One star forms the fourth point in the "Great Square of Pegasus"

Original 48 of Ptolemy: Yes

Area by size: 722.28 square degrees

Relative size: 19 out of 88 (Camelopardalis is next larger, Puppis is next smaller)

First Light Guides objects: Messier 31, Messier 32, 56 Andromedae, Gamma Andromedae

Brightest stars, in order of magnitude 

First lists the Bayer designation, then the "traditional" star name (often Arabic, but not always - see each star's notes for details).

  • α (Alpha) Andromedae (Alpheratz, Sirrah) magnitude 2.06, the 55th brightest star in the sky. It represents Andromeda's head in Western mythology, however, the star's traditional Arabic names – Alpheratz and Sirrah, from the phrase surrat al-faras – that means "navel of the steed". This is a reference to this star partially forming an asterism known as the "Great Square of Pegasus" with three more stars in Pegasusαβ, and γ Peg

  • β (Beta) Andromedae (Mirach) magnitude 2.06, is the 56th brightest star in the sky. Its name comes from the Arabic phrase al-Maraqq meaning "the loins" or "the loincloth".

  • γ (Gamma) Andromedae (Almach, Almaak) magnitude 2.15, is 62nd brightest star in the sky. Almach was named for the Arabic phrase ╩┐Anaq al-Ard, which means "the earth-kid", an obtuse reference to an animal that aids a lion in finding prey. Gamma Andromedae is one of the First Light Guides objects; it's object-locating guide is here.