Gemma, sometimes called Alphacca, forms with the stars Seginus and Arcturus, in Boötes, an isosceles triangle, the vertex of which is at Arcturus.
Close to ε a famous temporary appeared suddenly May 12, 1866, as a second-magnitude star. It was known as the "Blaze Star" and was visible to the naked eye only eight days, fading at that time to a tenth-magnitude star, and then rising to an eighth-magnitude, where it still remains.
The native Australians called this constellation "The Boomerang." To the Hebrews it was "Ataroth" and by this name it is known in the East to-day. No two of the seven stars composing the Crown are moving in the same direction or at the same rate.
α Coronæ is seventy-eight light years distant and sixty times brighter than the sun.
HERCULES (her´-kū-lēz)—THE KNEELER.
Location.—A line drawn from either Vega, in Lyra, or Altair, in Aquila, to Gemma, in Corona Borealis, passes through this constellation. The left foot of Hercules rests on the head of Draco, on the north, and his head nearly touches the head of Ophiuchus on the south.
The star in the head of Hercules, Ras Algethi, is about 25° southeast of Corona Borealis.