Tuesday, September 15, 2009

Pleiades and Andromeda M31

Three nights ago I tried to find the great nebula in Andromeda (M 31). I used Stellarium to try to identify the stars and hop from place to place. Unfortunately, I had a grouping of star patterns that I saw in the sky and couldn't quickly identify in Stellarium because of the difference in seeing and what Stellarium was trying to show me. I dialed the light pollution up to a 9, and then I found the grouping after some magnification, but quickly lost it again.

Last night, the seeing was exceptionally good. I started with the Pleiades, and was surprised to see how many stars were in the grouping just with my binocs. It certainly is a beautiful sight. At that point I decided to try to find the nebula in Andromeda again. It took some doing, but I finally got to see it after about a half hour of trying last night and spotted it at 1:30am!

Using Cassiopeia as a starting point, I used the three brightest stars to help me point to Mirach (or Merak) (β Andromeda). From Mirach, I went due North, to a grouping of stars which made a triangle, followed that grouping to ɥ Andromeda, to ʋ Andromeda, and finally to the nebula. Here's a graphic to show the hop:

Step 1

Step 2

Step 3

Step 4


  1. Hi Krish,

    Good job locating M31. I'm a little spoiled here in Arizona, with averted night vision I can faintly see it with the naked eye. In the Northwest near all the light pollution around the Puget Sound, I recall stepping through the same kind of star-walking to find it.

    By the way, M31 is the closest galaxy to our own.

  2. Hey thanks Andy, that means a lot to me, coming from you! I'm flattered!