Andromeda – Our sister in the galactic family

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Astronomy for RVers

By Chris Fellows, Serenity Mobile Observatory

Winter is here and that means some pretty cool, very large and, for some people, naked-eye objects in the heavens. Last time we looked at Orion and some of the fantastic objects within its boundaries, so I thought that this installment should carry on with that theme and direct our gaze to another glorious target in the winter’s night sky.

The Andromeda Galaxy (Image by Chris Fellows)

This object is going to be a little harder to spot. The constellation Andromeda isn’t particularly bright or large and some people have a hard time picking it out. If you have been following my column you may remember way back in “Let the stars be your road map – Part 1” I showed you how to find the north star, Polaris, by spotting either the Big Dipper (Ursa Major) or the large “W” (Cassiopeia) when looking north in the night sky. This time we are going to use Cassiopeia again but move in the opposite direction from Polaris.

Luckily for us in the Northern Hemisphere, Cassiopeia is visible almost all the time – just face north and you should be able to spot it. When you look at Cassiopeia you will notice that the “W” has one narrow and one wide side. In other words, it is an asymmetrical “W” and looks like a child’s attempt at the block letter. If you think of the narrower side of the “W” as an arrow head, it is pointing almost directly at the Andromeda constellation and the galaxy we are looking for.  Click on the sky chart (below right) for more information.


Sky Chart to Andromeda

In a really dark and moonless sky, the Andromeda galaxy is a naked-eye target. You will be looking for a small smudge of a “cloud” in the area of the sky I have indicated. It is fun to see if you can spot this object without optical aid, and it is a good measure of the quality of your observing location if you can.

A much better view can be obtained through a pair of binoculars or a small telescope. With these instruments you should be able to pick out some structure in the galaxy: dark dust lanes, a central bulge of stars, and two orbiting dwarf galaxies! Take your time and make sure your eyes are well dark-adapted. Also make sure your binoculars or telescope is well stabilized with a tripod or other mounting device.

Andromeda is a large galaxy, at least twice the size of our own Milky Way, and contains an estimated 1 trillion stars. It is also known as Messier 31, M31, or NGC 224, and is approximately 3 million light-years from Earth. It is the nearest major galaxy to the Milky Way and is on a direct collision course with us! You shouldn’t worry too much about the impending crash, however. It will take about 4.5 billion years (the age of the earth) for the collision to take place, and since galaxies are mostly empty space they will pass right through each other like two colliding clouds. The night sky, however, will be absolutely spectacular as the monster approaches, and I envy anyone still around to see it.

Go out this winter and see if you can spot Andromeda and let me know if you do. It is always a thrill to find one of these objects on your own and to realize it has been up there your whole life and most people never even notice.

Till next time!

Clear Skies,
Chris Fellows, Serenity Mobile Observatory

Find Chris on Facebook (or, if you’re lucky, at your campground). (Editor: Check out his amazing photos on his Facebook page!)