The “Vampire” Star

February 26, 2010

If you have a little time for stargazing this week, check out the tiny constellation Lepus just south of the great hunter Orion.   Often overlooked for more famous constellations, Lepus, the Hare, holds two delightful objects worth examining with a small scope or binoculars.

There are many legends of how Lepus came to be among the stars.

The Roman writer Hyginus wrote of a man who brought hares to the island of Leros to raise them for food.  A few escaped, and before long the island was overrun with voracious rabbits who consumed crops and caused a famine among the human population.  The hares were eventually driven out, but the inhabitants placed Lepus among the stars as a reminder of their experience.

The poor celestial hare forever runs from the Big Dog, Canis Major.  Perhaps that’s why he’s cowering in the hopes of a little protection at the feet of the great hunter.

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Lepus’ two brightest stars lead the way to the constellation’s only Messier object.  Find alpha Leporis (Arneb) and beta Leporis (Nihal), and extend a line south as long as the separation between the two stars.  There you’ll find the globular cluster Messier 79 right next to the 5th magnitude star HIP 25045.

The constellation Lepus, just south of Orion.  M79 is at the bottom of this image; R Leporis is marked by the circular cross-hairs at the middle-right.

M79 shines at magnitude 8.5, so it’s viewable in binoculars in dark sky and easily seen in a small telescope.  It’s fairly compact… just 1/10 degree across, and difficult to resolve near the center, even in an 8-10″ scope.  Some astronomers believe M79 comes from a nearby dwarf galaxy that’s interacting with the Milky Way.  The cluster lies at a distance of 43,000 light years.

But the jewel of Lepus is the deep-red variable star R Leporis, also called Hind’s Crimson star.  Like the star La Superba, R Lep is in the late stages of its life and has begun to churn up carbon from its core.  Once in the star’s atmosphere, the carbon blocks all but red and infrared wavelengths, which gives the star is crimson hue.  It looks like a drop of blood hanging from a vampire’s fang.

Hind’s Crimson Star (R Leporis)

Like many carbon stars, R Leporis is a variable star, changing from magnitude 7.3 to magnitude 9.8 every 420 days.  The fainter is gets, the redder it looks.  This is not a naked-eye object; use your optics to find this lovely star about 3 degrees west of mu Leporis.

Posted in Celestial Objects



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