Cool Stuff In Cassiopeia and Andromeda

by Mike Grilley

I guess the first thing to do is to find Cassiopeia. It's the "W": It's about 28° from the North Star, almost directly opposite of the Big Dipper and about equally far away.

Let’s take a quick aside for a moment: How to use your hands to measure the degrees I talk about. First extend your arm to its full length, then the “Degrees” your fingers cover will be as follows:

Pinky Finger = 1°

The First 3 Fingers = 5°

A Closed Fist = 10°

Index Finger to Pinky (Bull Horns) = 15°

Thumb to Pinky (hang loose symbol) = 25°

As you can see, Cassiopeia will be about a “Hang Loose” away from the North Star.

Since Cassiopeia rotates around the North Star, it will look like a "W", or an "M" or an "E" depending on its location. When you find it, you will need to imagine it as if it were a "W" to find the proper references I will be mentioning. I find it helpful if I turn my head to the side in order to see Cassiopeia as a “W”.

First we will use the "Left Leg" of the W. It consists of two stars: Segin (the end of the W) and Ruchbah (the vertex of the W leg). They are ~4.75° apart (4°47’57” to be exact) or about 3 fingers.

The first object on our list will be M-103, a very nice open cluster. It is located just slightly outside (less than 1°) of the line connecting the two stars of the W (Segin & Ruchbah), and about 1° (or a pinky) from the point of the W (Ruchbah). Did you find it? Great!!

Next on the list is the constellation of Pegasus, specifically the "Great Square" of Pegasus. Imagine a line extending from the Left Leg of the W away from the North Star. Extend it about 38° (a “Hang Loose” plus a “Closed Fist”), just a little further than Cassiopeia is from the North Star. You should see a fairly bright star (Mag 2.06) named Alpheratz. This is the brightest star in the Great Square, and the closest one to Cassiopeia. Now, the Great Square consists of the four brightest stars in the area. Alpheratz, which we found using the left leg of Cassiopeia, then clockwise we have Scheat, Markab and Algenib. They are about 15° apart (“Bull Horns”) from each other. Do you see them? Outstanding, you have found the Great Square of Pegasus!!

Now, let's use Pegasus to find the constellation of Andromeda. Remember Alpheratz? Look at it. Having trouble? No problem, see the square? Do you see the "side" of the square that "faces" Cassiopeia? If that is the "top" of the square, then Alpheratz is the star on the left. Okay? Got it? Great! Let's continue. If you imagine a diagonal line back toward Cassiopeia (from Markab through Alpheratz) you should see a set of two stars, one on top of the other (about 6° or 3 fingers from Alpheratz). Remember we are imagining the square to be sitting flat with Alpheratz as the top left corner. The lower star is Delta Andromedae and the upper star is Pi Andromedae. Keep going until you see another set of stars stacked one on top of the other, but a little farther apart and a little brighter (about 14° from Alpheratz). Those stars would be Mirach on the bottom and Mu Andromedae on the top. Keep going, there will be two more “stacked” stars, the bottom one is Almach and it is just as bright as Alpheratz, the other is 51 Andromedae. These 6 “stacked” stars make a kind of cornucopia and along with Alpheratz they make the constellation of Andromeda!

We're doing great so far, now lets find a very nice and very large DSO: M-31, the Andromeda Galaxy! To find it we will use the same line we imagined from Cassiopeia to find the Great Square, remember, from the left leg of Cassiopeia to the upper left corner of the Great Square (Alpheratz). Keep this line in mind as we go back to the "cornucopia" of Andromeda. Find the second set of "stacked" stars (Mirach and Mu Andromedae). Now draw a line through these two stars back toward Cassiopeia. Can you imagine where our two lines cross? Well, this puts you in the right area for M-31! On a clear night, you should see a small "fuzzy spot" with your naked eyes... See it? Well, guess what? That's M-31, the Andromeda Galaxy! It is on the line we drew from Andromeda and slightly off the line from Cassiopeia (closer to Andromeda).

So far we have found two constellations and two Messier objects, but there are two more Messier objects very close to M-31. They are M-32 and M-110, both are smaller galaxies and can be hard to find since they are so close to the very large and very bright M-31. Remember our line from Andromeda? M-32 is slightly closer to Andromeda and M-110 is slightly farther away with M-31 in the middle. Keep looking they really are there.

Since we are here, let's use our "Andromeda Line" to find M-33, the Triangulum Galaxy. Just extend the line the other way (away from Cassiopeia) about twice the distance we went to find M-31 (or about 7° - 3 fingers + a little bit). Bingo! You now have M-33.

Okay, back to Cassiopeia. This time we will use the "Right Leg" of the W. Schedar is the vertex and Caph is the end of this leg of the W. They are approximately 5° (Remember? That’s 3 fingers) apart. Start at Schedar and draw a line through Caph, keep going from Caph just a little farther than the distance from Schedar to Caph or about 6°. Voila, you now should see M-52 a nice Mag 8 open cluster.

That about does it for using Cassiopeia as a pointer. You should now be able to easily find the constellations of Ursa Major (the Big Dipper), Cassiopeia, Pegasus and Andromeda. Using the stars in Cassiopeia and Andromeda you should now be able to pinpoint M-31, M-32, M-33, M-52, M-103 and M-110.

There are several more Messier objects in the immediate area as well: M-76 the Little Dumbbell Nebula, M-34 a Mag 6 open cluster, M-74 a nice face-on spiral galaxy, and M-39 a Mag 5.5 open cluster. Good hunting!