If you think dogs are great and that's why the southern February evening constellation Canis Major is translated as "great dog", then you're missing the point that it is so named as to distinguish it from the nearby constellation Canis Minor...the "lesser dog". Portrayed in the night sky as hunter Orion's dog forever pursuing the adjacent star group Lepus (the hare), Canis Major's greatest feature is Sirius, easily the brightest star in the night sky at -1.46 magnitude, only some 8.6 light years distant making it a celestial neighbor of ours. Sirius is a binary star, the much dimmer companion a very dense white dwarf star, "the Pup", almost the exact size of Earth but much, much more massive. The rest of Canis Major contains a number of readily visible stars, making it easy to find in the evening sky, just to the southeast of Orion with that constellation's three-star "belt" roughly pointing in Sirius' direction. It also contains a Messier object, M41...an open cluster visible to the naked eye at 4.5 magnitude. It shouldn't be too hard to find this constellation on a clear twilight during February...just look to the southeast (from continental U.S. latitudes) as the sun sets and Sirius should stand out as the first star to become visible as the blue background darkens...
Next month I will examine another constellation...
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