Sky Talk February 2010: A Winter Campfire in the Sky

The vision of family and friends sitting around a campfire on a cold winter’s night with the stars brightly shining overhead conjures up fond memories for many who enjoy the outdoors at this time of year. Whether or not you’ve personally experienced this, the sky itself currently offers a celestial version of this charming scene for all starlovers to enjoy.

The evening sky after darkness falls this month contains the greatest concentration of bright colorful stars to be found anywhere. Known to most as the “Winter Circle Asterism” (or sometimes as the “Heavenly-G”), those of us more fancifully inclined prefer to see here instead a celestial campfire. To trace it out, begin by setting your Edmund Scientifics Star and Planet Locator (#30092-27) for 8 p.m. local time for mid-February (which also shows the way the sky looks at 9 p.m. the beginning of the month and at 7 p.m. at the end). Facing due south, you’ll be immediately dazzled by the radiant constellation Orion the Hunter standing astride the meridian.

Directly above Orion and positioned high overhead is the lovely golden sun Capella in the pentagon-shaped constellation Auriga the Charioteer. Proceeding counterclockwise, we come to the bluish-white star Castor and it slightly orange neighbor Pollux, both in the figure of Gemini the Twins. Continuing southward is yellowish-white Procyon in Canis Minor, the Small Dog, and below it the brightest star in the entire heavens — the dazzling blue-white diamond Sirius in Canis Major the Big Dog. Heading westward now we encounter another bright blue-white gem, Rigel in Orion. We complete the circle of those sitting around the campfire by heading northwest to the upper right of Orion, where we find orange Aldebaran set against the sparkling V-shaped glow of the big Hyades star cluster in Taurus.

Now only one thing is missing to complete this celestial imagery — the campfire itself! Sitting nearly smack-dab in the center of the circle is magnificent ruddy-orange Betelgeuse in Orion, appearing like some great glowing ember in the sky. So firelike does it appear that many stargazers swear they can feel its hot wind in their face on cold winter nights! In any case, looking at it definitely does bring a feeling of warmth, real or not.

In pointing out the hues of the various stars above, it should be mentioned that differences in their colors is primarily an indication of differences in temperature (not composition, as many believe). Hot stars are bluish-white and cool ones are ruddy, while those in between in temperature (like our own Sun) are yellow or orange. Thus, it’s actually possible to tell something of the physical nature of other stars simply by looking at them! And as J.D. Steele pointed out more than a century ago, “Every tint that blooms in the flowers of Summer flames out in the stars at night.”

A final word — you’ll find additional information about seven of the eight stars discussed above, including their distances, on the reverse side of the Star and Planet Locator. The exception is Castor, which technically is just below the cutoff for being a “first-magnitude” star. Its distance is 52 light-years from us.

–James Mullaney
Former assistant editor at Sky & Telescope magazine and author of seven books on stargazing.

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