Mizar: A Double Star Known for Generations

My guess is Mizar is the first double star most people ever see. When Ursa Major (the “Big Dipper”) takes its place high in the springtime sky, casual skygazers can point out the bright double star in the middle of the ladle called Mizar. Its companion, called Alcor, shines almost as bright, making both stars a pretty-looking pair in binoculars. If someone takes a look through any small telescope, the view of Mizar and Alcor gets even better as a smaller third star (called Mizar B) shows up on the scene!

In recent years, astronomers have confirmed the stars are gravitationally bound, versus just being optically close. What’s more, they move together across the galaxy at around 80 light years away from us.

So if you are reading this, and have never taken a moment to enjoy Mizar, stop and do so. As author Bob King points out in his article in Sky and Telescope, Mizar does command out attention with its history of firsts. It was the first “double star discovered (1617). First binary photographed in a telescope (1857). First spectroscopic binary (1890).”

My Observations

Tonight is my first time viewing Mizar through a larger scope in many years. I still remember being 9 or 10 and seeing Mizar with my K-Mart telescope. Tonight, I appreciate the white, diamond and shimmering clarity of the these stars in the eyepiece. I’m enjoying the view with my zoom eyepiece dialed at 24mm.

Key Stats

Historical Observations

I recommend reading the online article titled A New View of Mizar.

Sources and Notes

Photo of Mizar Banner: Sebastien Lebrigand from crépy en valois, FRANCE. This file is licensed under the Creative Commons Attribution-Share Alike 2.0 Generic license.

Sketch by Wayne McGraw

AKA: Zeta Ursae Majoris