Albireo: A Stunning Double Star of Indigo and Gold

Albireo is a celestial gem. It is a stunning double star due to the sharp contrast between its indigo and gold color. The star is visible to the naked eye from the suburbs. Simply look up at the constellation Cygnus (the swan), and locate the swan’s head. The star there is Albireo. By the way, Cygnus is also known as the Northern Cross. In this setting, Albireo is the bottom star of the crucifix. Observers have used several color combinations to describe the double star (such as deep yellow and pale blue) to various shades (such as topaz yellow and sapphire blue). ¹

This famous pair lies more than 400 light years away from us. While astronomers now believe the two stars were born around the same time, there is uncertainty regarding if the stars are gravitationally bound. They may simply be an optical double in the night sky. Size wise, both of these stars are no weaklings. The brighter golden star is five times our sun’s mass, and it’s actually a red supergiant. Meanwhile, the secondary blue star is 2.7 times the sun’s mass. ²

Many consider Albireo one of the prettiest double stars in the universe. Luckily, light pollution doesn’t affect viewing the double all that much. It’s a must-see star.

My Observations

As I update my sketch of this wonderful double tonight, I notice my entry from 2 years ago. COVID-19 still makes the news from time to time, but life goes on. On a recent trip across the country, I noticed a few masks here and there in airports—the first time I’ve seen masks in some time—a reminder of a different day at the beginning of this decade. I’m grateful for time and that the pandemic in the rear-view mirror faded away into a dark canyon behind us.

Observed first on July 29, 2021, at 10:20 p.m.: Alberio is a breathtaking night sky object. Even on this warm, hazy, and muggy evening, Alberio breaks through with its contrasting stars of gold and blue. Looking through the scope, my mind wanders. The golden hue of the primary star makes me think of hope for a day when COVID-19 fades away like a wisp of smoke.

The secondary blue star, though, dims my thoughts. It’s a reminder: This pandemic is not over. Instead, a variant continues to spread with the ICUs filling up fast. Our summer escape will not happen.

The light leaving Albireo today will not shine on this earth for 400+ years. Centuries from now, perhaps a backyard astronomer will peer at Albireo. And for a brief moment, their mind might float away, wondering what some backyard astronomer was experiencing years ago on a summer pandemic night.

Key Stats

Constellation	Cygnus
Best Viewing	Summer
Visual Magnitude	+3.0 | +4.7
Absolute Visual Magnitude	-2.5
Distance from Earth	420 ly
Separation	34.6″ | 4610 AU
Orbital Period	Unknown
Milky Way Location	Orion Spur
My Viewing Grade	A+

Sources and Notes

Banner shared under the Creative Commons Attribution-Share Alike 4.0 International license. Photo by David Ritter. Details here.

Sketch by Wayne McGraw

¹ Argyle, Robert W., et al. “Albireo.” An Anthology of Visual Double Stars, Cambridge University Press, Cambridge, 2019, pp. 800–801.

² Exquisite Albireo, a much-loved Double Star. EarthSky. (2021, July 31). Retrieved April 30, 2022, from https://earthsky.org/brightest-stars/albireo-finest-double-star/

AKA: Beta1 Cygni, 6 Cyg, SAO 87301