Jimmy Westlake: The Polish king’s shield
July 22, 2007
Most of the 88 official constellations in the sky represent mythological characters passed down to us from the Babylonian, Greek and Roman civilizations thousands of years ago. Those include familiar constellations such as Orion the Hunter and Ursa Major, the Great Bear. Others are more recent additions to the sky, only a few centuries old, like Antlia the Air Pump and Horologium the Pendulum Clock (yes, those are real constellations!).
There are only two constellations, however, that can be traced back to real historical figures. One is Coma Berenices, a spring constellation representing the hair of Queen Berenices of Egypt. The other is the summer constellation named Scutum Sobiescianum, or Scutum for short. It represents the shield of John Sobieski, the Polish king who defeated the Turks in the 1683 Battle of Vienna. By chance, the king was a friend of Polish astronomer Johannes Hevelius, and seven years after the defeat of the Turks, Hevelius invented the constellation of Scutum Sobiescianum, Sobieski’s Shield, to honor his king. Hevelius is credited with inventing seven of our 88 constellations. Besides Scutum, he invented Canes Venatici (the Hunting Dogs), Lacerta (the Lizard), Leo Minor (the Little Lion), Lynx (the Lynx), Sextans (the Sextant), and Vulpecula (the Fox).
Scutum is an obscure little constellation, to be sure, with no star brighter than fourth magnitude and ranking only fourth in size among all the constellations. Still, it is an easy constellation to find in the summer sky and well worth the effort to locate because it includes one of the brightest patches of the summer Milky Way within its borders, the so-called Scutum Star Cloud. Only the Sagittarius Star Cloud, located much farther to the south, outshines the Scutum Star Cloud. On any dark, clear summer night, the Scutum Star Cloud stands out prominently against the black sky. Look for it just south of the bright Summer Triangle star Altair.
A good pair of binoculars will magically transform the Scutum Star Cloud into thousands of glittering stars and, with a small telescope, you should be able to spot the famous Wild Duck star cluster, also known as M11. The brightest of its 3,000 stars form a distinctive “V” shape, resembling a flock of flying ducks.
Jimmy Westlake teaches astronomy and physics at Colorado Mountain College’s Alpine Campus. He is an avid astronomer whose photographs and articles have been published on the Web sites of CNN.com, NASA’s “Astronomy Picture of the Day,” Spaceweather.com, Space.com, Discover.com, and in Sky & Telescope, Astronomy, Night Sky, Discover, and WeatherWise magazines.