The mild evenings of May are an ideal time to see the most famous of all star patterns—the Big Dipper. (Many think of it as a constellation but it’s actually an “asterism,” being a distinctive part of Ursae Major, the Big Bear of the heavens.) And it can be used as your personal guide through the starry spring sky.
Of the 88 officially recognized constellations, all or part of 66 of them are visible from mid-northern latitudes. And these can be found using the Big Dipper as a guide! Here, we will just concentrate on those visible in the sky this month. So follow along on our celestial journey using your Scientifics Star and Planet Locator set for whatever date in May you venture outside. You will notice on the chart the stars and constellations of winter setting in the west and those of summer rising in the east. But it’s the spring ones we want to concentrate on now.
Everyone seems to know that the two stars at the end of the Dipper’s bowl point upward to Polaris (the North Star) anchored to the handle of the Little Dipper in Ursae Minor, the Little Bear. But following these same pointer stars downward points to the constellation Leo, the Lion. Its distinctive sickle-shaped head contains the bright blue-white star Regulus. On the way down to Leo, note the tiny figure of Leo Minor, the Little Lion. Following the curve of the Dipper’s
handle brings us to the kite-shaped constellation Bootes, the Herdsman. It luminary is the brilliant orange star Arcturus, brightest of all those in the spring sky. And continuing the curve downward brings us to the Y-shaped constellation Virgo, the Virgin. Its bright star is bluish Spica—nicely contrasted with Arcturus’s hue. So five constellations and three bright stars so far!
Next, just under Virgo lies the distinctive constellation Corvus. This supposedly represents a Crow, but most stargazers see it as a sailboat with a lantern at the top of its mast. Going back to the Big Dipper, prolonging a line from the top left star in the bowl through the bottom right one brings us to rather dim Cancer, the Crab. And at its heart lies the famed Beehive Star Cluster. On a dark moonless clear night, the eye sees a hazy patch of light here. Using “averted vision” (looking to one side of it or the other) makes it definite. In binoculars of any and all sizes, this stellar jewelbox is truly a superb sight not to be missed!
There are other less obvious mostly dim constellations that can be found using the Big Dipper (just look under its handle for Canes Venatici and Coma Berenices as two examples). Using other combinations of the stars in the bowl as pointers can lead to others. But those mentioned above are the real highlights of the spring sky.
— James Mullaney
Former assistant editor at Sky & Telescope magazine & author of 10 books on stargazing. His latest, Celebrating the Universe!, is available from HayHouse.com.