Night Lights: December brings merry stargazing

By Andy Veh, for the Redoubt Reporter

Rising in the east and gaining altitude throughout the next two months are the great winter constellations Orion with seven bright stars, among them red Betelgeuse and blue Rigel, and the Orion nebula stellar nursery.

Also visible are Taurus with red Aldebaran and its prominent star cluster, the Pleiades; Auriga with yellow Capella; Gemini with the twin stars Castor and Pollux; the head of Canis Major with the brightest star (aside from the sun) that we can see from Earth, Sirius; Procyon in tiny Canis Minor; and, very late in the evening, Regulus in Leo.

Because this region of the sky hosts seven of the 20 brightest stars as seen from Earth, and because it contains quite a few easily recognizable constellations, it is my favorite region of the sky.

High in the south is the Great Square of Pegasus in the shape of a diamond. Above it, close to the zenith, is Cassiopeia. Getting close to the western horizon, but never completely setting in Alaska, are the three stars that make up the summer triangle, Deneb in Cygnus, Vega in Lyra, and Altair in Aquila (that one actually does set — just barely for a few hours).

In the north are Ursa Major’s Big Dipper and Ursa Minor’s Little Dipper, the latter always really close to 60 degrees, our latitude on the Kenai.

Planets at night

Only Jupiter is visible, next to Taurus’ red giant Aldebaran and with the star cluster Pleiades nearby. It appears all night long, moving from southeast to the northwest throughout the night, setting just prior to dawn. Look for Jupiter right next to the full moon on and around Christmas Day. If you have friends in South America or Africa, let them know because our moon occults Jupiter as seen from their vantage point.

Planets in the morning

Venus shines brightly in the southeast before sunrise, joined by the waning crescent moon Dec.11. This is the last month to see Venus, during January it’s in upper conjunction (on the other side of the sun) and will not be visible again until fall of next year because once it emerges from behind the sun, it’s already late spring and the evenings are too bright, too long.

Venus just passed Saturn late last month. As Venus goes into hiding, the ringed planet will become more prominent in the morning sky all winter long. Look for Saturn higher in the sky than Venus, near the southeastern horizon. The waning crescent moon is close on Dec. 9 and 10.

All other planets — Mercury, Mars, Uranus and Neptune — appear too close to the sun so that they can’t be seen against the bright daytime sky.

The winter solstice is Dec. 21, when the northern hemisphere’s axis points away from the sun, giving us the shortest day (with the sun about five hours above the horizon) and the lowest sun in the sky at only 7 degrees above the southern horizon at noon.

Finally, verbatim from Sky & Telescope magazine, December 2012 issue: “… the Mayan calendar flips over to a new baktun, … contrary to the doomsayers, no astronomical catastrophe will ensure.” Please don’t call me since I’m not interested in this and have nothing to say about it. I will enjoy a normal Christmas with my family.

Andy Veh is an associate professor of physics, math and astronomy at Kenai Peninsula College.


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