One Bright Star Leaves, Another Arrives

An interesting thing about the northern part of the sky is how few really bright stars are close to the North Celestial Pole (NCP).  However, there are two very bright stars that are close enough to the North Celestial Pole to almost be circumpolar (meaning they never rise or set but are always above the horizon); one is Arcturus and one is Capella.

Arcturus is the brightest star in Bootes (pronounced Boo-oh-tees) the Hersman.  Arcturus is easy to find by following the curve of the Big Dipper's handle; follow the Arc to Arcturus.  Arcturus is the brightest star in the Northwest part of the sky.  

Turning to the Northeast we find Capella, the brightest star in Auriga the Charioteer.  To find Capella use the top two stars of the Big Dipper's bowl and follow them to the East.  Capella is the brightest star in the Northeast part of the sky.  

Both Arcturus and Capella are brighter than 1st magnitude and are almost the same temperature.  Arcturus is spectral type K and Capella is spectral type M, meaning they are both cool as stars go; cooler even than our sun.

While the  brightest stars are generally near or south of our local zenith, Arcturus and Capella are two of the brightest stars near the North Celestial Pole, and Fall is the only time the are both visible in the evening sky.

Capella and Arcturus visible in the evening sky.  Created with Stellarium.