What Else Can You Find?

In another entry, I talked about the Big Dipper and how you can find the North Star with it.  It turns out the Big Dipper is a great pointer to another bright star in the sky. If you take the curve of the handle of the Dipper and follow it out in an arc, you come to the bright star Arcturus, the brightest star in the constellation of Boötes.

Arcturus is an interesting star. It’s slightly orangy-colored K-type star (making it older, cooler, 1.5 times more massive than the Sun and appears larger than the Sun).  I was interested to read over at Jim Kaler’s Stars site that astronomers think that Arcturus comes from an older population of stars in the Milky Way. It’s even possible that Arcturus was part of a smaller, dwarf galaxy that merged with the Milky Way in the distant past.

Arcturus is seismically active  — meaning that it goes through physical oscillations,  just as other red giants do. It’s a variable star, meaning that its brightness changes slightly every few days.  Interestingly, when you look at Arcturus, you’re seeing what the Sun could look like as it goes into its red giant phase in a few billion years.

Arcturus is another one of those bright stars that everybody on the planet (well, nearly everybody) seemed to observe throughout history. People used it for navigation and seasonal predictions having to do with harvesting food.  Today, you can simply look up and marvel at this star that lies only about 37 light-years away from us. Just remember to “arc to Arcturus” from the handle of the Big Dipper. It’ll take you on a curvy path across the sky to this slightly reddish, bloated star.  Enjoy!