Here in New England, we had a spectacular starry sky tonight. The moon was a thin crescent, and disappeared soon after sunset. By about 10 o’clock there were quite a few recognizable constellations in the dark sky to the west. Cygnus (the Swan, also called the Northern Cross), pointed downward and filled a big patch of the sky. Below and left of Cygnus was Aquila (the Eagle). On the other side, toward the bottom right of Cygnus lies the constellation Lyra (the Harp). Each of these three constellation has a prominent star, Deneb — the tail of Cygnus, Altair — the eye of Aquila, and Vega in Lyra. All three stars make up the Summer Triangle. Cygnus has an interesting star, Albireo, which is in fact a binary system comprised of a blue-white star and a companion red giant. With good eyesight and a steady hand, you might be able to make them out using binoculars; I could see them quite clearly with my 70 mm telescope. The dramatically different star colors are quite a visual surprise the first time you see them. Two other small, but easily recognizable, constellations are located between Cygnus and Aquila — Delphinus (the Dolphin) and Sagitta (the arrow). On the opposite side of the sky, I could see the constellation Cassiopeia, but it was against brighter background glare from the metropolitan area. The nearby Andromeda galaxy was also visible in my telescope, but only appeared as a faint, nearly round, smudge. With our light polluted skies, much of its long oval shape is obscured.
It was quite a show tonight, and viewing will be good tomorrow evening as well (clear skies are forecast). With Aquila getting closer to the Western horizon, the constellation Orion (the Hunter) will begin to appear in the East in another month or so. And winter won’t be far behind.
Update: I heartily recommend H.A. Rey’s Find the Constellations. If the stars are unfamiliar to you, it’s great place to start learning. No telescope or binoculars required.
Cygnus image from http://www.allthesky.com, a visual guide to the constellations.