Harry Potter fans may boo when they hear its name, but Bellatrix, one of the stars of Orion, is nothing to sneer at. It’s one of the hottest, brightest stars in the neighborhood. It forms one of Orion’s shoulders. As night falls this evening, it stands to the upper left of Orion’s Belt and to the upper right of the hunter’s other shoulder, orange Betelgeuse.

The Harry Potter universe is filled with characters named for stars and constellations. The best known are Bellatrix Lestrange and her cousin, Sirius Black, who was Harry’s godfather. Other members of the family include Orion, Cygnus, and Regulus, the brightest star of Leo.

Sirius is the brightest star in the night sky. It’s low as night falls, below Orion’s Belt. Sirius looks so bright in part because it’s about 25 times brighter than the Sun, and in part because it’s one of our closest neighbors — just 8.6 light-years away.

Bellatrix is much more impressive. It’s tens of thousands of degrees hotter than the Sun, and thousands of times brighter. The key to that power is the star’s mass — about eight or nine times the mass of the Sun. Heavier stars burn through the nuclear fuel in their cores in a hurry, so they produce far more energy than stars like the Sun.

Such stars pay a price for their showiness, though — they live much shorter lives than less-massive stars. In fact, Bellatrix is probably nearing the end of its life — the end of one of Harry Potter’s greatest enemies.
 

Script by Damond Benningfield

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