Looking Up: Spinfully Delightful

December 26, 2016
Gomeisa, the "bleary eyed one" located in Canis MoinorCredit Nigel Whitworth / https://www.universeguide.com/star/gomeisa
Gomeisa, the "bleary eyed one" located in Canis Moinor

This week on Looking Up Hal makes our collective heads spin with this information about the star Gomeisa.

If you got a telescope for Christmas and would like to take it out for a spin, please feel free to contact the Colorado Springs astronomical Society for help. And when you do, maybe we can show you a star that definitely got taken out for a spin, the very interesting star Gomeisa!

You’ve probably heard of the wonderful constellation, Orion the Hunter. Orion strides across the winter sky, forever chasing, but not quite catching, his prey, Taurus the bull. And you may also know that Orion is not alone. The constellation Canis Major, or the big dog, containing the brightest star in the sky, Sirius, is Orion’s companion on the hunt. But did you know there’s another companion too?

The constellation Canis Minor, or the little dog, trails behind Sirius, and contains the eighth brightest star in the sky, Procyon, which we discussed back in January. But Canis Minor contains another very interesting star, the little-noticed Gomeisa. Gomeisa is actually much brighter than Procyon, but it’s 15 times farther away at 170 ly. It’s 250 times brighter than our sun, and is at least three times bigger. That alone would make it a very interesting star, but there’s something else special about Gomeisa, and that has to do with taking it out for a spin.

Gomeisa, like all stars, rotates on its axis. Our own sun rotates once every 24 days or so, near the equator. If you were standing on the equator of the sun, you would, very briefly, be moving at about 4500 miles per hour. I say very briefly because you would very briefly be turned into plasma, though in fairness that plasma would still be moving at 4500 mph.

But Gomeisa spins to a different tune. This remarkable star rotates not once every 24 days, but rather, once every 24 hours!

If you were to – briefly- stand on Gomeisa’s equator, you would be moving at the amazing speed of 560,000 miles per hour. So if you’re going to go, I recommend a healthy dose of Dramamine.

If you’d like to take a closer look at Gomeisa, or any of the other wonderful and amazing things in the sky, please visit CSASTRO.org for a link to information on our monthly meetings and our free public star parties! 

This is Hal Bidlack for the Colorado Springs Astronomical Society, telling you to keep looking up, Southern Colorado!