Stargazing: The Double Star Alberio

September 3, 2012 12:15 am

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The clear nights of late summer and early autumn offer stargazers a great opportunity to grab a small telescope or binoculars and take a look at the hidden beauty of the night sky.

This weekend, when the waning gibbous moon has departed the evening sky, look overhead in the Summer Triangle constellation of Cygnus for the high-flying double star Alberio.

Seen at even slight magnification through binoculars or a small telescope, the third magnitude Albireo unfolds from a single point of light into a beautiful double star. At 380 light-years distant, the contrasting bright "golden yellow" primary star and "sapphire blue" companion have been called the most beautiful double stars in the sky. These two bright stars orbit around a common center of gravity under their mutual gravitational attraction.

Look for Cygnus, the celestial Swan, high overhead around 10 p.m. Deneb, the brightest star in Cygnus, marks the swan's tail. Alberio, down and to the right of Deneb, marks the swan's head.


First Published September 3, 2012 12:00 am

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