Looking Up: Borrow Some Barium?

Apr 29, 2019

The en:Corvus and en:Crater constellations drawn by Johannes Hevelius in Uranographia, his celestial catalogue in 1690. Scanned by: Torsten Bronger 2003 April 4
Credit public domain / wikimedia.org

In a continuation from last week's episode of Looking Up, we learn more about the constellation Corvus the Crow. This week Hal spotlights another star in that constellation - Kraz - which seems to be a star that's down on its barium essentials.

Some things in our Colorado night sky are fun because we know a lot about them. But there are far more items up in that sky that we really don’t know too much about, yet.

One of these somewhat mysterious objects is the star Kraz, in our Spring sky as part of the constellation Corvus the Crow, which is a fun, roughly diamond-shaped constellation, low in the southern sky. Kraz means, well, we don’t really know. Once source says it means “left-handed lynch pin” which is not commonly thought of as a part of a crow. It’s about 160 times brighter than our Sun. It’s a giant, about 18 times bigger than the Sun, and it appears to be all alone, with no companion star in the neighborhood. But this is where it gets a bit weird. Astronomers can use spectrometers to see what chemicals a star is made of. And Kraz has far less barium than it should have. We think stars only get this way when they’ve been pushed around for a few billion years by bigger and more massive companion stars. But Kraz does not appear to have any such companion. So maybe Kraz is a whole new type of star, or maybe the spectrometer reading is, for some reason, not accurate. Only Kraz knows for sure, and it’s not talking. 

Beta Corvi (β Corvi, also named Kraz, lower left) is the second-brightest star in the southern constellation of Corvus.
Credit IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg) / wikimedia commons

If you’d like to take a closer look at Kraz or any of the 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.