Skywatchers this month have an ideal opportunity to see the two brightest of all the stars of the northern heavens at the same time. Not only are they brilliant and unmistakable—but they also display a truly striking color contrast between them sure to surprise anyone who thinks that stars are all just plain white!
High in the sky facing south on June evenings is the wonderful radiant gem known as Arcturus, located in the constellation Bootes. Following the curve in the Big Dipper’s handle downward brings you right to it. But it’s so bright and commanding that you likely won’t need to resort to using the Dipper to find this star. Arcturus has a decidedly warm glow to it, much like that of the planet Mars to its southwest. Among the heavenly hues assigned to it by stargazers over the years are orange, reddish-yellow, golden-yellow, topaz, peach, rosy champagne—and even the color of a shiny new copper penny! Arcturus lies at a distance of 37 light-years from us, meaning that the light you see from it tonight left the star in 1977. Were you on the planet back then? And if so, what were you doing at the time?
Our second great luminary is Vega in the little constellation of Lyra. You’ll find it shining like a radiant blue-white diamond high in the eastern sky these evenings, positioned midway between Arcturus and the horizon. It lies somewhat closer to us than
does its orange stellar neighbor, at a distance of 25 light-years. Colors cited for Vega always involve some shade of blue and the star is said to be even bluer than Sirius, the brightest star in the nighttime sky. Penned over a century ago, the most exalted description of Vega I’ve ever encountered reads: “Resembles on old-mine Brazilian brilliant of purest water intensified to infinity!” I always see this glorious orb as a beautiful pale sapphire blue in hue. Binoculars often make perceiving star colors easier—especially if the image is very slightly defocused. This spreads the star’s light out over more of the retina (keeping in mind that the color-sensitive cones themselves lie at the center of the eye).
Now here’s an astounding and fascinating aside concerning these two great luminaries. It’s well known that Vega was once our Pole Star—and will become so again in 14,000 A.D. due to the 26,000 year processional cycle resulting from the Earth wobbling on its axis. But research far into the remote past indicates that at one time both Vega and Arcturus were close together in the sky, forming an amazing twin Pole Star! This was due to Arcturus’ rapid proper (or space) motion carrying it into our northern sky near Vega. The next clear night, look at these two great suns and in your mind’s eye imagine them gracing the heavens side-by side-where Polaris now resides. What a truly awesome sight that must have been!
— James Mullaney
Former assistant editor at Sky & Telescope magazine & author of nine books on stargazing. His latest, Celebrating the Universe!, is available from HayHouse.com.