Ah, December. Winter officially arrives on December 21 at 10:48 P.M. Central Standard Time although it already feels an awful lot like winter to me already. For me, the best part of winter is, of course, the day before spring begins! Winter isn’t all bad, just mostly bad which means there must be a little good. Right? Well, it does get dark enough to get out and get an hour or so of quality observing under your belt or parka and still be able to get back inside in time to watch prime time T.V. that’s good! Unfortunately, this winter there won’t be much in the way of early evening planets to keep an eye on they have all moved into the spring and early summer constellations of Leo (Jupiter), Virgo (Mars), Libra (Venus) and Ophiucus (Saturn).

Kidding aside, when the clouds part, December skies have a charm of their own. When the skies are clear in December it is generally really cold but if you can stand the cold you will be rewarded with inky black skies studded with some of the brightest stars visible in the northern hemisphere. I am often asked if the cold air makes the skies clearer and the stars shine brighter. The truth is that in winter we have traveled around the Sun so that it is between us and the center of our galaxy, the Milky Way. So at night when look up at the sky we are looking out away from the core and towards the edge of the galaxy where there are fewer stars littered across the sky.

The faint band of the winter Milky Way is still there, but it can be difficult to spot unless you can get away from light polluted skies. At about 7 P.M. it stretches from the eastern horizon between the constellations of Gemini and Orion, through the constellation Auriga, the home of bright Capella, through Perseus who holds Medusa’s head and her baleful glaring red eye, the variable star Algol. Continue tracing the faint outer arm through the “W” of Cassiopeia, finally ending with Cygnus, the Swan setting in the west. I’ve pointed this out before, but I like the fact that in December, the story of Christ is told in the stars as M44, the Beehive Cluster also known as Praesepe which means ‘Manger’ where Jesus was placed after He was born, rises in the east and the main stars of Cygnus which form an asterism known as “The Northern Cross” is setting in the west. Very poetic and to me, very meaningful. Some might scoff, but in Genesis, scripture says that on the 4th day God placed the stars in the sky; “And God said, ‘Let there be lights in the vault of the sky to separate the day from the night, and let them serve as signs to mark sacred times, and days and years, and let them be lights in the vault of the sky to give light on the earth.’ And it was so.” (Genesis 1:14-15 New International Version)

So with fewer Milky Way stars in the sky and less dust and moisture in the air, the few stars that remain really stand out, and it doesn’t hurt that many of them really are brighter than the stars in the summer sky, either! To identify just a few, go outside on a clear night around 9 o’clock and face east. The three belt stars of the constellation Orion will be lined up about 30 degrees up from the horizon. The stars are quite close you will be able to hide them behind 3 fingers held together at arm’s length. The star closest to the horizon is named Alnitak and it is magnitude 1.74 pretty bright! The next star up in the belt is named Alnilam and it shines at magnitude 1.69 almost the same as Alnitak. The third star in the belt is called Mintaka and it is slightly dimmer than the other two, shining at magnitude 2.25. Can you see the difference?

Straight to the left from the belt is the bright slightly reddish tinted star Betelgeuse. Betelgeuse is a red super giant star. It is the second brightest star in the constellation Orion, shining at magnitude 0.42 (Remember the smaller the number the brighter the star is.) and it is the 9th brightest star in the sky.

The brightest star in Orion is on the opposite side of the belt. It is called Rigel and like Betelgeuse it is a super giant star but instead of being tinged red it is white with perhaps a slight blue tinge how do you see it? Rigel shines at magnitude 0.18 and I think it is just beautiful.

The last star we’ll talk about this time is in the constellation Canis Major. You can find it by simply drawing a line from the three belt stars down toward the horizon. There, about 20 degrees from the lowest belt star, you will see bright blue-white Sirius. Sirius puts all the others to shame shining at magnitude -1.44! Sirius looks so bright because it really IS bright, shining 25 times brighter than the Sun and also because it is relatively close at just over 8 light years from our solar system. At 9 o’clock, it may not look so bright because in December it is just clearing the horizon then and the atmosphere makes it appear much dimmer. Later in the evening when it has gotten at least 25 or 30 degrees up, it will show its true glory and in the cold air it often sparkles and gleams as the changes in the atmosphere break up the light into flashes of red and blue like light shining through a prism.

One last thing to talk about this month is the annual meteor shower that peaks around December 14th called the Geminid Meteor Shower. The peak is actually spread over a few days: Dec. 4th through the 17th. This shower is a little unusual because the grains that burn up as they streak across the sky come from an asteroid instead of the tail of a comet. This asteroid is called Phaethon and it orbits the Sun over the Sun’s north and south poles instead of around the equator like Earth and the rest of the planets do. It orbits the Sun once every 1.52 years and crosses Earth’s orbit less than 1/10 the orbit of the Moon. Don’t worry though, we are not in danger of a collision, at least not any time soon. The moon will only be 3 days past new at this year’s peak so it will set soon after the sun and its light should not interfere. As the name suggests, the meteors will radiate from the constellation Gemini near the bright star Castor. If you watch on the evening of the 14th, some are predicting that you can expect to see from 50 to 130 per hour 1 to 2 per minute, on average. Might be worth braving the cold for a little while, at least. Clear Skies!