Stargazing this Week

Bright Stars on the Rise
The familiar constellations of Canis Major, Orion and Auriga are rising after dinner these days, making for a collection of bright stars near the Eastern horizon. Capella of the constellation Auriga is easy to spot once you find the Pleiades. Watch for Sirius of Canis Major later in the evening, below Orion. Above him, the moon soon will pass near Aldebaran, the red eye of Taurus the Bull. Deborah Byrd has a great write up on this massive star that has been popular with star gazers for Millenia.

Planets After Sunset
The other bright objects are still in the sky, although they’re setting to the Southwest earlier with each passing winter night. Jupiter - the brightest of these - now sets a bit after 9pm. The moon continues to rise relative to the planets as it grows in brightness. If the clouds allow, it can be instructive or at least fun to compare the planets - whose positions move daily - with the bright, fixed stars, night to night.

The Geminids
If you’re looking to spite the cold weather, it’s peak Geminid season! The Geminids are a meteor shower radiating from the bright star Castor, the right head of the constellation twins.

Unlike most meteor showers, the Geminid debris field is not from a passing comet. Rather, they come from a peculiar asteroid known as 3200 Phaethon. Despite being an otherwise inert space rock, it does leave behind a tail and a debris field for us to pass through. This astroid / comet hybrid has a highly eccentric orbit, passing through the orbits of all the inner planets. Scientists aren’t quite sure what causes its to stream a tail behind it, although EarthSky has a great write up on the object.

To view the Geminids, make plans to stay up until dawn, or rise obscenely early. Plan to be out for at last an hour in full view of the open sky, perhaps with a bonfire nearby. The meteors themselves will be faint - particularly with the waxing moon - so allow at least 20 minutes to let your eyes adjust to the dark.