Star-hop from Great Square to Andromeda galaxy

09sep24_430

Tonight for September 29, 2011

Because the thin waxing crescent moon will set shortly after sunset this evening, this will be a fine night for viewing deep-sky treasures, such as the Andromeda galaxy.

The Great Square of Pegasus is a great jumping off point for finding the Andromeda galaxy, otherwise known as M31. The Great Square sparkles over your eastern horizon at early evening, then travels westward across the sky throughout the night. For some idea of the Great Square’s size, extend your hand an arm’s length from your eye. You’ll see that any two Great Square stars are farther apart than the width of your hand.

Mars stirs up Beehive before dawn in late September and early October

As seen from mid-northern latitudes, the Square of Pegasus looks like a baseball diamond whenever it resides in the eastern sky. Imagine the farthest star to the left — Alpheratz — as the third-base star. A line drawn from the first-base star through Alpheratz points in the general direction of the Andromeda galaxy.

If it’s dark enough, you’ll see two streamers of stars flying to the north (or left) of the star Alpheratz. To me, this grouping of stars looks like a bugle or a cornucopia. Along the bottom streamer, star-hop from Alpheratz to the star Mirach. Draw a line from Mirach through the upper streamer star (Mu Andromedae), and go twice the distance. You’ve just located the Andromeda galaxy!

Mirach: Guide star to three galaxies

If you can’t see this fuzzy patch of light with the unaided eye, maybe your sky isn’t dark enough. Try binoculars! If you can find the Great Square of Pegasus, then you can star-hop to the Andromeda galaxy.

Andromeda galaxy, closest spiral to Milky Way

Share your comments on Facebook

14 Responses to Star-hop from Great Square to Andromeda galaxy

  1. Bob says:

    Hi, last night at about 11:00pm we were looking at a light high in the eastern sky of middle Georgia. It was the brightest light in the sky and after a few minutes it went dim, then in a few more minutes it light back up again. It did this the whole time we were watching it. There were no clouds and there was a sky full of stars. We was just wondering what it could be.
    Thanks,
    Bob

  2. Anne Culver says:

    Bruce, I love your methods of finding stars! I share them with a lot of camper-friends of mine. If it is clear tonight, I will look for the great square and then the Andromeda galaxy. So incredibly cool! I still have the star-wheel I made at the Long Lake Public Library!
    Best regards to A. and all
    Anne (from Maryland)

    • Bruce McClure says:

      Anne,

      What a wonderful surprise, hearing from you! If you’re ever back in the neighborhood, please visit us at Reynolds Observatory just outside of Potsdam, New York.

      Best wishes!
      Bruce

  3. wandy says:

    I love looking at the moon. I love when its right above my house because my yard lights up so beautifully. It just amazes me. Tonight the moon looks nice. Looks like someone is lighting it on its side with a flashlight. Simply amazing.

  4. Bo says:

    We saw it up here in Maryland too. It looks like a portend, but of what?

  5. Bo says:

    Glad you told me it was Jupiter – I thought I was blinded by Uranus

  6. JESilverstein says:

    I live in the heart of Seattle–enough light pollution to make observation difficult, but not impossible. My landmarks were Jupiter and Cassiopeia. I *think* I did this right: I looked at Cassie, and used each of its legs as reference points in the general directions of Andromeda (which is little more than a smudge here in the middle of town) and, in the opposite direction, the Great Square. Jupiter is just this dazzling, bright beacon in the sky tonight, outshining everything, at least from where I’m viewing.

  7. Sam says:

    So. I live in Pa. It is just past 3:00am. I woke with a dry throat n decided to get water, and take a look at the clear sky tonight. What I saw astonished me. There was a bright in the sky. Clearly to bright to be a star, and it would move or even wobble it seemed. Sometimes you could see as many as what is 2 tails coming of it. The first thing I thought was that perhaps it was that satellite that they said was falling to earth. Any conformation or explanation for this light?

  8. Bo says:

    How long will Saturn be so prominent in the night sky? Is this unusual – it sure seemed to be?

  9. [...] a good night to skywatch for less bright targets, because what little moon there is will set early. EarthSky.org has tips for following star pointers to see the galaxy Andromeda, with your eyes or binoculars. [...]

  10. jeremiah staley says:

    just to say, umh i live in moore county n.c. and if any fellow astronomers could answer WHY THERE WAS AN ENORMOUS FLASH OF LIGHT IN AQUILLA!!!!!!!! please coment

Share your comments on EarthSky

Your email address will not be published. Required fields are marked *

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>