In the days before calendars, ancient peoples used patterns of stars in the night sky to mark the passage of seasons and to prepare for upcoming ones. In the modern age, avid skywatchers anticipate season changes because different stars and stellar objects become visible, providing a new selection of things to see. As constellations make finding these stellar objects easier, we’ll continue to examine the constellations of Fall here in this edition.
Orion the Hunter is perhaps the most famous, and easiest Fall constellation to see. In ancient times, the arrival of Orion in the sky meant that it was time to begin hunting and gathering food for Winter. Located in the southern area of the sky, Orion is bright and easy to find. At the top left of Orion is the red supergiant star Betelgeuse, and at the lower right is the blue supergiant Rigel. Orion also contains the Orion Nebula and the M78 nebula in the region near the famous belt. Orion is easy to see, even in light pollution, so see if you can spot it!
Below Orion is another prominent constellation, Canis Major, one of Orion’s hunting dogs. Also in the southern sky, Canis Major is home to several open star clusters, and the brightest star in the sky. Sirius is a bright blue star that lies around 8 light years from Earth. The only objects brighter than Sirius are the Sun, Moon, and Venus. Sirius is also known as the ‘Dog Star’, as it is the eye of the dog. The term ‘dog days of summer’ comes from when Sirius becomes visible in the pre-dawn hours of late August. Canis Major also contains the largest known star, VY Canis Majoris. If it were located where the Sun is in our solar system, VY Canis Majoris would extend to the orbit of Jupiter! You would need a star chart and optical aid to find this hypergiant, but spotting it would enable you to see the largest known star to date!
Above Orion’s shield lies the constellation Taurus the Bull. Taurus contains two of the largest star clusters visible to the naked eye. The Hyades makes up the “V” which constitute the horns of the Bull. The orange giant star Aldeberan is part of the “V”, but not part of the Hyades cluster. It just lies in the path. The Pleiades are also located nearby, containing several dozen stars, but only 6 are visible to the naked eye. The Crab Nebula, Messier 1, is also located in Taurus. The Crab Nebula is the remnant of a supernova that occured in the year 1054, which was visible in broad daylight. A pulsar lies at the center of the Crab Nebula. Taurus is also a sign of the zodiac, as it lies in the ecliptic path that the Sun, Moon, and planets travel.
Looking to the northern sky, below Cassiopeia is the hero Perseus, the legendary slayer of Medusa in mythology. Perseus contains a number of unique stellar objects, like the Perseus Double star cluster, and the variable star Algol, also known as the “demon star”. Algol is a binary star system that varies in brightness every few days as the bright star is eclipsed by a dimmer one. The Double Cluster is located off the edge of Perseus’ sword near Cassiopeia and can be seen as a cloudy smudge with the naked eye. Perseus is also the origin point of the Perseid meteor shower in late July. Perseus is a neat constellation for observation!
Below Perseus and off the northern end of Taurus’ horns lies the constellation of Auriga, the Charioteer. Shaped like a huge pentagon, Auriga is another prominent Autumn constellation. It features 3 open star clusters (M36, M37, and M38), as well as the bright star Capella. Locating Auriga will allow you to see the beautiful open star clusters contained within. These clusters can be found with binoculars, but are best appreciated with a telescope with at least 40x magnification.
Finally, we have the constellation Gemini, found in between Orion and Auriga. Also a sign of the zodiac, and lying in the ecliptic as well, Gemini contains the twin stars Castor and Pollux. Gemini also contains an open star cluster, M35. The twin stars of Gemini are easily visible, but the remainder of the constellation can be difficult to see under light pollution or moonlight. Still, for those looking for open star clusters or the constellations of the zodiac, Gemini is a must see!
As the Fall season moves on into Winter, these constellations will become visible earlier in the evening, eventually giving way to the Winter constellations. The Fall sky contains a large number of deep space objects as well as some very prominent constellations, giving skywatchers a treat! And, with the Sun setting much earlier as we approach the Winter solstice, there is ample of time to gaze upon these wonders! So next time you feel stir-crazy, dress warmly and take a look up into the evening sky, and see what the night sky of Fall has to offer!
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