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January 28, 2017

The celestial rabbit occupies a perilous position in the sky: It’s below the feet of Orion, the hunter, and to the west of Canis Major, one of Orion’s hunting dogs.

Lepus is low in the southeast as night falls right now. It’s to the lower right of Orion and his three-star belt, and to the upper right of Sirius, the leading light of Canis Major and the brightest star in the night sky.

Lepus consists of a few moderately bright stars, although you might have a hard time connecting them to see a rabbit.

One of its most intriguing denizens is invisible to the eye alone. But telescopes have revealed that Gliese 229 may consist of at least three objects: a faint star, a brown dwarf, and a giant planet.

The star is smaller and cooler than the Sun, and much fainter. Because of its low mass, though, it’ll live billions of years longer than the Sun.

The star has an even smaller, fainter companion: a brown dwarf — one of the first ever discovered. It’s more massive than a planet, but not massive enough to shine as a true star.

And there’s evidence for a third member of the system — a planet that’s bigger and heavier than Neptune, one of the giants of our own solar system. The planet appears to be about the same distance from Gliese 229 as Earth is from the Sun. Because the star is so faint, though, that puts the planet well outside the habitable zone — the region where conditions are just right for life.

We’ll have more about Lepus tomorrow.


Script by Damond Benningfield

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