
Summer Triangle

Orion

Facing North
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Fall Semester: Early in the semester, high overhead, you will find three bright stars which make up
the summer triangle. Each star belongs to a different constellation: Vega belongs to Lyra, Deneb belongs
to Cygnus, and Altair belongs to Aquila. Vega and Deneb are the two stars along the short side of the triangle,
and Altair is the third star. Roughly speaking, the summer triangle points away from the north star, Polaris.
The magnitudes for these three stars are listed in the table below.
Now, look north. First, find the constellation Cassiopeia, which looks like a big M (or big W) in the sky.
When Cassiopeia looks like a big M, Schedar is the second star from the left (the first peak in the letter M).
The magnitude for this star is listed below as well. While facing north, also located the Big Dipper, and use
the pointer stars to find the north star, Polaris.
Spring Semester: Look south and find Orion in the sky. Identify the four bright stars: Betelgeuse
(the right armpit), Bellatrix (the left armpit), Saiph (the right foot) and Rigel (the left foot). The table
below lists the magnitude of each of these stars.
Now, look north. First, find the constellation Cassiopeia, which looks like a big M (or big W) in the sky.
When Cassiopeia looks like a big M, Schedar is the second star from the left (the first peak in the letter M).
The magnitude for this star is listed below as well. While facing north, also located the Big Dipper, and use
the pointer stars to find the north star, Polaris.
| Fall Semester |
| Star | Magnitude |
| Vega | 0.0 |
| Altair | 0.8 |
| Deneb | 1.3 |
| Alpheratz | 2.1 |
| Schedar | 2.5 |
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| Spring Semester |
| Star | Magnitude |
| Rigel | 0.1 |
| Aldebaran | 0.9 |
| Bellatrix | 1.6 |
| Saiph | 2.2 |
| Schedar | 2.5 |
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