A supermoon and a genuine super triangle
There’s a full moon this weekend over southwestern Minnesota but it’s not just any old full moon. It’s yet another supermoon. The only thing is, it’s not all that super. At the most it’s only 7 percent larger than an average full moon and 15 percent brighter. If you weren’t told that it’s a supermoon, you probably wouldn’t know the difference. The full moon this month is indeed a little closer than average to the Earth, but not all that much. What really bugs me about the usage of the term is that it’s not born out of astronomy. It’s astrology jargon, and astrology is nowhere near scientific!
OK, I’m done ranting. It’s off my chest. Now I want to tell you about something that really is super, the Winter Triangle.
Whenever you gaze upon the constellations it’s easy to forget that you see a three-dimensional picture. The constellations seem to be set against a black canvas, but that’s simply not the case. The stars that make up the constellations are all at varying distances from Earth, from tens of light-years to thousands of light-years away. There’s no way you can travel in a spaceship to Orion the Hunter. So when you see remarkable alignments of stars, like the three stars in a row that make up Orion’s belt, you have to be even more impressed. I know I am.
Another fantastic “accidental” alignment of stars is the Winter Triangle. It’s a perfect equilateral triangle, made up of three bright stars from three separate constellations. What are the chances of that? It’s available in the early evening southern skies this month, and all three stars are bright enough to see even in light-polluted heavens.
At the upper right-hand corner of the Winter Triangle is the super red giant star Betelgeuse, the second brightest star in Orion the Hunter. Betelgeuse is an Arabic name that roughly translates into the “armpit of the great one.” That’s right, Betelgeuse marks Orion’s armpit. You can easily see that Betelgeuse has a distinct orange-reddish hue.
Astronomically the star Betelgeuse may be the biggest single thing you’ve ever seen! It’s a humongous star that pulsates in size like a giant celestial heart. In roughly three years, it swells from a diameter of more than 600 million miles to almost a billion miles before shrinking again. Our sun is a wimp compared to Betelgeuse. It’s less than a million miles in diameter. By the way, own Earth is less than 8,000 miles across. Eventually Betelgeuse is going to put on the ultimate fireworks show. It will explode, what astronomers refer to as a supernova. When this happens Betelgeuse could turn as bright as a full moon and stay that bright for weeks. It’s a good thing Betelgeuse is more than 500 light-years away or the Earth would be in a world of hurt. Astronomers have observed that Betelgeuse has been dimming significantly in the last few years. Some astronomers are taking this dimming as a sign the explosion may be coming soon but don’t bet the farm. It still may not happen for millions of years. In fact, Betelgeuse has been brightening up a bit again in the last several weeks
The very bright star Sirius is another star in the Winter Triangle. In fact, Sirius is the brightest star in the night sky and the brightest star in the constellation Canis Major, Orion’s big hunting dog. Sirius marks the eye of the big hound. Sirius is at the bottom of the triangle, and as you can see in the diagram, the constellation Orion’s three belt stars point directly at it. Sirius is a Greek name that translates to English as “the scorcher.” Way back then, many civilizations believed that when Sirius was close to the sun in the sky in late summer, they teamed up to make it really hot!
The remaining star in the Winter Triangle is Procyon, the brightest star in the constellation Canis Minor, the little dog. To find it, simply look for the next brightest star you can see to the upper left of Sirius. Procyon is a little farther away than Sirius, about 11 light-years away.
That’s it, the perfect Winter Triangle, three stars from three different constellations that physically have nothing to do with each other, yet show incredible symmetry in our heavens! So is it just a coincidence, or not? You decide.
Celestial happening this weekend: This Sunday, March 8, in the early evening, the very bright and close planet Venus and the very dim and distant Uranus will be in fairly close conjunction. With a small telescope or binoculars, look for Uranus a little more than two degrees to the lower left of Venus. That’s about the width of two of your fingers held together at arm’s length. Uranus may have a slightly greenish tinge to it and is over 1.9 billion miles away!
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul.