By Mike Lynch
This week in Starwatch I want to take you to the low southern skies for one of the best constellations of summer over Everett: Sagittarius the Archer. Not only is Sagittarius easy to find, it’s also in the direction of the center of our Milky Way galaxy, home of our sun and at least two hundred other stars with even more planets. Some possibly like our Earth.
As soon as it’s dark enough, around 9:30, look in the low southern sky just above the horizon. You want to make sure your view is fairly unobscured with a low tree line. An open field is best. Look for a distinct pattern of eight fairly bright stars that clearly draw a teapot. Unless there is a lot of light pollution where you are it should be easy to see. There are four stars on the left-hand side that make up the handle, three stars on the right that make up the spout, and one in between that marks the top of the teapot’s lid.
That celestial teapot is actually what astronomers call an asterism, a very easy to see pattern of stars that isn’t actually a constellation. In this case the teapot asterism is the brightest part of the official constellation Sagittarius the Archer. According to Greek and Roman mythology, Sagittarius depicts a centaur shooting an arrow. In case you’ve never run into one, a centaur is a mythological creature with the head, arms, and torso of a man and the body and legs of a horse. With some imagination you may be able to see how the teapot could outline the upper body of the centaur shooting an arrow. The handle would outline the bent arm of the shooting centaur and the spout would draw out the bow and arrow.
It’s really great this time of year if you can get out to the countryside and stargaze away from city lights. It’s in the dark summer skies that you can clearly see the bright band of milky light stretching from the northern horizon to the southern horizon. You’re looking sideways into the disk of stars that make up most of the stars in our galaxy. There are so many stars in the band and they are so far away that you see their combined light all mashed together.
The constellation Sagittarius, on the southern end of the Milky Way band, is in the direction of the center of our galaxy, about 26,000 light years away (one light year is nearly six trillion miles). The downtown section of our home galaxy would appear a lot brighter in our sky, but there’s a lot of obscuring interstellar gas and dust in the way. Many astronomers believe that if it weren’t for all that gas and dust, the part of the sky around Sagittarius would be brighter than the full moon. Nonetheless, that part of the Milky Way band around the Teapot is still fairly bright and loaded with a lot of celestial treasures. Even with a small telescope or a pair of binoculars you’ll find many star clusters and nebulae.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, “Stars, a Month by Month Tour of the Constellations” published by Adventure Publications available at bookstores at http://www.adventurepublications.net