Great Square of Pegasus

Tiny points of light, with a magic all their own.
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Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Great Square of Pegasus

Post by Christopher K. » September 17th, 2015, 9:25 pm

This well-known asterism is high enough these nights to be explored by about 9:15pm. Sunday night I used the Great Square to find both the major stars of Andromeda and the "W" of Cassiopeia--not that the Square is necessary.

One pertinent point. The three main stars of Andromeda are Alpheratz (actually used as a corner of the Square), Mirach and Almach. They line the northeast from upper right to lower left and so they are always at different altitudes--but they are also the same magnitude, 2.1. By comparing their brightnesses at any one time an estimation of light pollution and/or stellar extinction can be gathered.

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Great Square of Pegasus

Post by Christopher K. » October 13th, 2015, 9:24 pm

Try viewing the Great Square right after nightfall between tomorrow night and Friday night. The constellation Pegasus is brilliant tonight and there's every indication that the clouds will stay away this week. I look at Pegasus at ~8:15pm tonight and not just the Square stars, but mag 2.9 Matar and mag 3.4 Homam were good-looking too. (Homam is dimmer than Albireo!)

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Great Square of Pegasus

Post by Christopher K. » September 3rd, 2017, 8:44 pm

The lowest corner of the Great Square, Algenib, hits twenty degrees at 9:16pm CDT Tuesday night. The fall sky is coming into being even as the temperature is forecast to get a little chilly overnight this coming week. It may not last, but it's a fine precursor to salvation from months of cloudy swelter.

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