Arcturus: The Great Light Switch of the Chicago World’s Fair

Whenever I see Arcturus, I imagine standing with 30,000 other people at the opening of the Chicago World's Fair on May 27, 1933. At 9:15 that evening, observatories in four locations across the eastern U.S. aimed their scopes on Arcturus. The bright star's light set off photocells at each location. In turn, these devices sentContinue reading "Arcturus: The Great Light Switch of the Chicago World’s Fair"

Coma Star Cluster: An Egyptian Queen’s Long Hair

The Coma Star Cluster is nearby open cluster in the constellation Coma Berenices. It's best viewed in the spring. Open any app or astronomy book with drawings of the constellations. While looking at Coma Berenices, you'll see a cluster of around 40 stars and few cascading bright stars that make up the queen's long-flowing hair.Continue reading "Coma Star Cluster: An Egyptian Queen’s Long Hair"

Messier 40: Also Known as Messier’s Greatest Mistake

Springtime galaxy hunting in Ursa Major is an awarding experience. Observers have their pick of Messier objects from the awe-inducing Whirlpool Galaxy (Messier 51) to the bright Cigar Galaxy (Messier 82). Then, scrolling through these notable Messier objects, one lands upon Messier 40. Aiming the scope at M40 uncovers a simple pair of stars—no nebula,Continue reading "Messier 40: Also Known as Messier’s Greatest Mistake"

Xi Ursae Majoris: A Binary Star Close to Home

Xi Ursae Majoris, also known as Alula Australis, is a double star in Ursa Major. It's best viewed in winter. This binary system is notable for many reasons: It's a close binary system to earth — only 25 light years away. It was the first binary system to be discovered. William Herschel discovered it inContinue reading "Xi Ursae Majoris: A Binary Star Close to Home"

Cor Caroli: A Binary Star with a Heart of a King

Cor Caroli is a double star in the constellation Canes Venatici. It’s best viewed in spring. The primary star, at a magnitude of 2.9, shines a white blue, while the dimmer companion, at a magnitude of 5.5, shines a warm yellow. This contrast of color makes for an attractive pair in the warming spring sky.