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,ContinueContinue 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 inContinueContinue 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.

Zeta Cancri: A Multiple Star System in Cancer

Zeta Cancri is a multiple star system in the constellation Cancer. It’s best viewed in the spring. For many years, astronomers believed Zeta Cancri to be a triple star system, though now it has been found to be a quadruple system. According to Jim Kaller, the close binary pair (known as Zeta Cancri A andContinueContinue reading “Zeta Cancri: A Multiple Star System in Cancer”

Delta Geminorum (Wasat): A Star With a Unique History

Wasat is the primary star in a triple star system in the constellation Gemini. It’s best viewed in the winter. At magnitude +3.5, Wasat is not difficult to find under suburban skies. As you look at Wasat, you’re looking at a historical area of the night sky. In February 1930, Kansas farmboy-turned-astronomer Clyde Tombaugh discoveredContinueContinue reading “Delta Geminorum (Wasat): A Star With a Unique History”

Struve 747: A Pair of Light Blue Topaz Stars

With many competing targets in the Orion neighborhood, it may be easy to overlook notable double stars such as Rigel and Struve 747 (also known by HR 1887). Struve 747 is a 4th magnitude double star in Orion and a worthy target on any winter night. When observing the pair, you’ll notice they are prettyContinueContinue reading “Struve 747: A Pair of Light Blue Topaz Stars”