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The Little Dog

StarDate: 
December 6, 2018

The big dog trots across the southern sky on these late-autumn nights — the constellation Canis Major. It’s conspicuous thanks to its leading light: Sirius, the Dog Star — the brightest star in the night sky. It climbs into view in the southeast by about 10 p.m. right now, but it’ll rise earlier as autumn gives way to winter.

Canis Major is escorted across the sky by the little dog, Canis Minor. It’s to the upper left of the big dog in late evening.

Under a fairly dark sky, it’s not hard to see Canis Major as a four-legged animal. But Canis Minor is another story. On most charts, it’s drawn as a single line connecting two stars.

One of those is quite easy to spot, though, because it’s also one of the brightest stars in the night sky: Procyon, a star whose name means “before the dog.” The name indicates that, from mid- to high-northern latitudes, which includes most of the United States, Procyon rises before Sirius.

Like Sirius, Procyon is a close neighbor — in this case, a bit more than 11 light-years away. The star itself is similar to Sirius, which means it’s bigger, hotter, and brighter than the Sun.

And also like Sirius, it has a “dead” companion — a white dwarf. The companion was born more massive than Procyon, so it burned out more quickly. The companion is too faint to see without a telescope. And even with a telescope, it’s so close to Procyon that it’s quite difficult to spot through the glare.


Script by Damond Benningfield

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