The constellation Triangulum is one of the few examples where the connect-the-dots thing really does resemble the name. I mean, it makes a pretty damn good triangle without resorting to your imagination. Even the ancient Babylonians couldn’t come up with a great name for these stars so their astro-geeks called it “the plow” which was considered high-tech and trendy back then.
Eventually Claudius Ptolemy added the name to his maps as the triangle and if Claude did it then we have to also, that’s the rule.
The ancient Chinese called it “Heaven’s Great General” which frankly, suggests to me they were getting tired of coming up with good names for these things and just wanted to be done with it.
The brightest star of the three, Beta, is just beginning to give away some of its things and getting ready to move off the main sequence. Its new address is in Starhaven Estates, an assisted living retirement facility in the upper east side of the H-R diagram.
The second brightest star of the triad, Alpha, a name which means “Brightest Star of the Group But Sometimes Second,” is an over-achieving sub-giant, shining much brighter than other stars of its class.
The third leg of the stool is Gamma. It’s a working class star like our sun, earning a normal paycheck by crushing hydrogen and cranking out helium.
The story might end there except for something exceptional. Triangulum is the home of M33, a face-on spiral sometimes called the Pinwheel Galaxy. Actually M101 is also called the Pinwheel Galaxy. They can both be called the Pinwheel Galaxy, I don’t care. In this age of self-identification I can be a Pinwheel Galaxy too if it makes me happy. But if we ever develop warp drive we should probably sort this out or someone is going to get lost.
You can faintly pick out M33 with your naked eyes if you get out of the city and it’s nice and dark, with no moon, or clouds, or kids shining flashlights in your face. Binoculars or low power telescope views are best because it is big and spread out with low surface brightness. Over-magnifying it will risk making it, and you, appear rather dim.
Our Milky Way has about 30 close friends and M33 is a mere 2.3 million light years away. That’s not close enough to just pop in, I would still call first, but it’s near enough that the local gravitational curvature of space-time prevails over the cosmic expansion, at least at the current level of dark energy influences. So we’re neighbors.