Spotting the Celestial Unicorn
Last updated 3/28/2023 at 1:39pm
Have you ever been disappointed to search for a constellation figure in the heavens only to discover that it was utterly impossible? Trust me, you're not alone!
Take, for example, the flying steed known as Pegasus. I defy anyone to look skyward and outline its stars in such a way that they can see a flying horse. And, if you can, well, I'm afraid you'll need more help than I can give you!
No, constellations just aren't real but are simply groups of randomly distributed stars that ancient storytellers created to represent objects, animals and people. Their combined stars appear nothing like their namesakes, at least not without plenty of imagination (or chemicals), so don't feel bad that you can't recognize them.
One particularly unrecognizable star grouping lies in our evening sky right now. It's known as Monoceros, the unicorn. Monoceros is composed of faint and obscure stars, and we often overlook it because it happens to lie among some of the most brilliant stars in all the heavens. With the moon out of the evening sky this week, you can search for it just to the east of dazzling Orion and between the bright stars Sirius and Procyon.
It's tough to know where constellation stories and names originate. Often their roots are lost in antiquity, but we think that Monoceros may have a more modern origin. Some believe that it might have been the 16th-century Dutch theologian, cartographer and astronomer Petrus Plancius who invented this constellation, though some think it might have been named "Unicornu" by German astronomer Jacob Bartsch who published Plancius' star maps in 1624.
If you can identify Monoceros in a dark moonless sky (which is pretty much the only way it's possible), you should also be able to see the faint wintertime Milky Way flowing gently southward through it.
Once you find Monoceros, you'll discover it takes quite an imagination to fashion a unicorn from its stars. But it's not so much the constellation that's interesting as what's lurking within. Though they're rather faint, quite a few celestial wonders are visible if you have a small telescope to aim in this direction.
Monoceros is home to a beautiful triple star system – three stars that orbit a common center of gravity – known as Beta Monocerotis. It was the famous astronomer William Herschel who discovered it in 1781, the same year he found the planet Uranus. Herschel found the three stars of Beta Mon to form a triangle that, from our distance of about 700 light years, appears not to change over time, and he described it as one of the best triple star systems he'd ever seen.
Also lying within the boundaries of Monoceros is the famous interstellar cloud named the Rosette Nebula that engulfs a star cluster known as NGC 2244. With a backyard telescope, one can sometimes make out some diffuse nebulosity here, but it takes a pretty hefty scope to distinguish its ringed shape.
Even if you don't own a large enough telescope to show these celestial wonders, I hope you'll at least seek out the unicorn. I suspect it'll be the only one you ever see!
Visit Dennis Mammana at dennismammana.com.