Throughout the year, the stars of the celestial dome make up a plethora of pictures and patterns. Most of what we see are the individual constellations that were used by ancient cultures as visual aids to tell tales of mythology that vary from culture to culture. Most of the tales best known in this part of the world are spin-offs of Greek and Roman mythology. While different cultures have their own mythologies, all of the constellations are pictures of the characters that make up these soap operas of the night sky.
Another common thread is that most of these constellations don’t look much like what they’re supposed to portray. As I say at my star parties, you really have to put your imagination into overdrive to see what they’re supposed to represent. That’s OK in my book, though, because it’s part of what makes casual stargazing so much fun.
Many constellations display some pretty unique geometrical shapes and asterisms. The connecting lines of stars in the constellation Cassiopeia the Queen resemble a giant “W” in the heavens. The right side of the constellation Leo the Lion outlines a backward question mark. The constellation Auriga the Chariot Driver looks like a lopsided pentagon. One of the best constellations is made up of the seven stars that form the rear end and tail of Ursa Major the Big Bear. You see that every clear night as the Big Dipper.
There are much larger asterisms in the sky that use stars from several adjoining constellations. These can be great tools in learning constellations. One of these is known as the Summer Triangle, which is made up of the brightest stars from three separate constellations. At the corners are Vega, the brightest star in the constellation Lyra; Deneb, in the constellation Cygnus the Swan; and Altair, in the Aquila the Eagle. Each one of these stars is the brightest shiner in their home constellation. The Summer Triangle is easy to see in the summer and autumn sky, and can be a good tool for helping you find your way around that part of the celestial theater.
The very best asterism of the night sky, in my opinion, is the Winter Triangle, now on display in the southeastern early evening sky. It’s a perfect equilateral triangle made up of three bright stars from three separate constellations: Betelgeuse, from the constellation Orion the Hunter; Procyon, the brightest star in the small constellation Canis Minor the Little Dog; and Sirius, the brightest star in Canis Major the Big Dog. Unless you’re viewing from a lighted shopping mall parking lot, you should have no trouble spotting the perfect Winter Triangle because of the brilliancy of its member stars. In fact, Sirius, at the bottom of the triad, is the brightest star available in the night sky.
Sirius and Procyon are almost twice the diameter of our sun and are more luminous, but the main reason they’re so bright in our heavenly dome is that they’re relatively close to the Earth. Procyon is 11 light-years away and Sirius is just over eight light-years in distance (one light-year equals just under 6 trillion miles). It would take much more than a long weekend to journey to those shiners! In fact, if you flew to Sirius in a jet airliner averaging 500 miles per hour, it would take you more than 11 million years to get there. They better have meals and movies on that flight.
Sirius can be a whole lot of fun to view through even a small telescope. That’s because it never gets very high in the sky, and its light has to travel through much more of Earth’s blurring atmosphere to reach our eyes. If upper air winds are strong and there’s a lot of turbulence, Sirius can appear as a changing kaleidoscope of colors as its light rays get bounced around.
The third star of the perfect triangle, Betelgeuse, is a huge star almost 650 light-years away. This super red giant star is almost a billion miles in diameter, and sooner or later will burst in a colossal supernova explosion, maybe within the next million years, if you feel like waiting up for it. Until then, you can see the upper right hand member of the Winter Triangle shining brightly and sporting an easily seen reddish hue.
It’s amazing to me that these three stars making up the perfectly proportioned Winter Triangle just happen to be positioned the way they are in the winter sky. Coincidence? Or not?
CELESTIAL HUGS
This week in the early morning southeast twilight sky the waning crescent moon will be passing by the bright planets Venus and Jupiter. It will be absolutely lovely!
