July's Star

This month look for the star Gemma in Corona Borealis. Corona Borealis is Latin for Northern Crown and is a crescent shaped pattern of seven stars located on the back of the constellation Bootes. In Greek mythology, Corona Borealis is the crown given to the mortal Ariadne by the Greek god Dionysus on their wedding night. After his wife died of old age, Dionysus placed the crown in the heavens as a symbol of his eternal love for Ariadne.
 
Gemma is a bright white star. Gemma is 2.7 times heavier than our sun. Its greater mass makes it almost twice as hot as the sun, 67 times brighter, and about three times larger. However, it’s not one of the brightest stars in our sky on account of its distance of 75 light years (you would need binoculars to see the sun 75 light years away). If you know someone who was born in 1940, then Gemma is his or her birthday star this year.

Look for Gemma nearly overhead in the west-northwest after dark. To find it, follow the handle of the Big Dipper to the bright yellow-orange star, Arcturus high in the west. Corona Borealis is located almost straight up from Arcturus.