This week, let’s take a last (well, close to the last) look at the Summer Triangle. This unofficial constellation (astronomers call it an “asterism”) is prominently visible in our prime-time sky from summer through fall. It consists of the three brightest stars from three different constellations: Vega, in Lyra the Lyre, Deneb in Cygnus the Swan, and Altair in Aquila the Eagle. As a side note, the Milky Way runs through this part of the sky from Aquila to Cygnus, as if the Eagle and Swan are flying toward each other over the celestial river. There’s an astronomy lesson inherent in these three stars as well. Vega and Altair are both relative neighbors, at just 25 and 16 light years away respectively. Deneb, though almost as bright as the other two in our sky, is about 2,600 light years away. At that distance, you would need at least a medium-sized telescope to see our sun at all. We see Deneb so brightly because it is tens of thousands of times more luminous than the sun.
“The Sky This Week” appears every Tuesday. It is written by Ian Clarke, Director of the Hatter Planetarium at Gettysburg College. The planetarium offers regular educational presentations about the stars and the skies; there’s something for early elementary through adults. Field trip requests are welcome. NOTE: field trip request form for Fall 2022 is now live, and the schedule of free public shows has been posted. Our next set of shows will be an “Astro Afternoon” on Sunday, October 16, with shows at 1:00, 2:00, 3:00, and 4:00. Follow the link above for details.
Ian Clarke is the director of the Hatter Planetarium at Gettysburg College. In addition he has taught introductory astronomy labs and first-year writing there for over 30 years (not necessarily all at the same time). He was educated at Biglerville High School, the University of Virginia, and the University of Iowa. He lives in Gettysburg.