Betelgeuse and Siwarha

Hello, friends!

I love space, but I also love language and words and names, and I especially love it when people put thought and care into the naming of things.  Betelgeuse is a super famous supergiant star in the constellation Orion.  For as long as I can remember, it was generally assumed that Betelgeuse was a loner.  A single star, all by herself, with no binary companion.  But now it seems that Betelgeuse does have a very small, very faint companion star, which astronomers have (very aptly) named Siwarha.

Back in 2019/2020, astronomers noticed Betelgeuse start to flicker and dim.  There was a rapid 30% decrease in Betelgeuse’s brightness, leading to rampant speculation that Betelgeuse was about to go up in a supernova explosion.  That would have been an amazing sight for all of us here on Earth!  But then, nothing happened, and Betelgeuse’s brightness eventually went back to normal.

The Great Dimming of Betelgeuse, as this event is now called, was caused by something less spectacular than a supernova (less spectacular, but still interesting—check out the “want to learn more?” section below if you want to learn more).  Still, during the Great Dimming, Betelgeuse got a lot more attention from astronomers than usual, and astronomers started noticing patterns in her behavior—including a pattern that (based on reexamining historical records) seemed to repeat every 2100 days.

One possible explanation: maybe Betelgeuse has a companion star with an orbital period of 2100 days.  This hypothetical companion star was initially nicknamed “Betelbuddy.”  But then, in December of 2024, astronomers at the Gemini North Observatory in Hawaii were able to directly image “Betelbuddy” in mid-orbit.  At that point, Betelgeuse’s companion stopped being hypothetical, and somebody needed to give it a more official-sounding name.

Betelgeuse is an Arabic name (as most traditional star names are), and it means something like “the hand of the giant.”  The giant in question is, of course, Orion; however, the Arabic name for Orion is al Jawza, which is a female name from Arabian legend.  Therefore, since this newly discovered star circles round and round the hand of a lady giant, the Gemini North team proposed naming it “Siwarha,” meaning “her bracelet.”

How perfect is that?

Siwarha would have been hidden behind Betelguese during the Great Dimming, so it was not visible to Earth-based astronomers at that time, no matter how hard they looked for it.  Even after Siwarha emerged from behind Betelgeuse, spotting it stretched the limits of one of the very best telescopes in the world.  After crossing in front of Betelgeuse, Siwarha should appear again (on the opposite side of Betelgeuse) in late 2027, at which point astronomers should be able to learn much, much more about it.

WANT TO LEARN MORE?

Here’s a brief article published by NASA announcing the discovery of Siwarha.

And here’s a link to the actual research paper explaining how the Gemini North team detected Betelgeuse’s companion star.  The proposal to name it “Siwarha” is near the end of the paper.

As for the Great Dimming of Betelgeuse, it was caused by Betelgeuse burping a big, giant cloud of dust up into space, which partially obscured our view.  Click here to learn more about that.

P.S.: The art in today’s post is my own original work.  If you like my art, please consider visiting the I-Love-Space store on RedBubble.  Even if you don’t buy anything, just visiting and clicking the “like” button on some of my work helps me a lot (and if you do decide to buy something, that obviously helps me even more!).  Thank you!