Dazzling Christmas constellations visible in the winter sky

December 22, 2010 - 0:0

The Yuletide evening sky should provide a dazzling sight for anyone willing to brave the cold this season.

The eastern sky is filled with brilliant stars, creating a sort of celestial Christmas tree. This December 2010 sky map depicts a view of some of the constellations visible on Christmas in the Northern Hemisphere.
Distinctive groupings of stars forming parts of recognized constellations, or lying within their boundaries, are known as asterisms. Ranging in size from sprawling naked eye figures to minute stellar arrangements, they are found in every quarter of the sky and at all seasons of the year. 
The larger asterisms – ones such as the Big Dipper in Ursa Major and the Great Square of Pegasus – are often better known than their host constellations. One of the most famous asterisms is in the northwest sky these frosty evenings. 
Originally known simply as the “Bird” in ancient times, without any indication of what sort of bird it was supposed to represent, one star grouping later became the constellation Cygnus, the Swan. 
But the brightest six stars of Cygnus compose an asterism more popularly called the Northern Cross.  Bright Deneb decorates the top of the cross. Albereo, at the foot of the cross, is really a pair of stars of beautifully contrasting colors: A third magnitude orange star and its fifth magnitude blue companion are clearly visible in even a low-power telescope. 
While usually regarded as a summertime pattern, the Northern Cross is best oriented for viewing now, appearing to stand majestically upright on the northwest horizon at around 08:30 P.M. local time in the Northern Hemisphere, forming an appropriate Christmas symbol. Furthermore, just before dawn on Easter morning, the cross lies on its side in the eastern sky.
Look over toward the southeast part of the sky at around the same time. Can you see a large package in the sky, tied with a pretty bow across the middle?  Four bright stars outline the package, while three close together and in a straight line form the decorative bow. 
This is a picture easily put together by our modern imagination, but tradition tells us that those seven stars form a mighty hunter called Orion, the most brilliant of all constellations and visible from every inhabited part of the Earth. Two stars mark his shoulders, two more his knees and three his belt.
As is also the case with the mighty Hercules, the figure of Orion has been associated in virtually all ancient cultures with great national heroes, warriors, or demigods. Yet, in contrast to Hercules, who was credited with a detailed series of exploits, Orion is more of a vague and shadowy figure. 
The ancient mythological stories of Orion are so many and so confused that it is almost impossible to choose between them. Even the origin of the name Orion is obscure, though some scholars have suggested a connection with the Greek “Arion,” meaning warrior. 
All, however, agree that Orion was the mightiest hunter in the world, and he is always pictured in the stars with his club upraised in his right hand. Hanging from his upraised left hand is the skin of a great lion he has killed, which he is brandishing in the face of Taurus, the Bull, who is charging down upon him.   The heavenly manger
(Source: Space.com)