The Witch Head Nebula in Eridanus Image © Darrell Dodge (Dec 11, 2011- EGK Dark Site)

January Skies
by Dennis Cochran

etus wags his tail in the early evening at the southern meridian. All of the classical Winter constellations are in the eastern sky now, with the Pleiades just above the ecliptic leading the charge. Below the ecliptic Aldebaran stands out in front of the V-shaped Hyades star cluster, too spread out in the sky to have become an M-object but existing instead as the constellation Taurus the Bull, a powerful figure in Mesopotamian and early Greek culture. There is an M-object there, however, in the eastern extension of the Bull's lower horn just above the Zeta star of Taurus: M1, Messier's list starter, the Crab Nebula. This exploded star actually looks like an explosion frozen in time that has nevertheless changed slightly in the decades that humans have photographed it. The bright star at the extension of the Bull's upper horn is actually Beta Auriga. Here is another star which seems to share in two constellations, just like the northeast corner star of the Pegasus Great Square belongs to Andromeda.

From the area of the sky southeast of Aldebaran a line of south-falling stars outlines Orion's shield, being held aloft west of his shoulder star Bellatrix. Down in his sword's scabbard M43 is the small blob above the larger one, M42, famous as the Orion Nebula stellar nursery. If you're an imager, the region of the Hunter is full of nebular phenomena including Barnard's Loop, a huge quarter-circle east of the three belt stars. The top of its arc ends above the belt stars, and below that a smidgen, two thirds of the way down the line from Betelgeuse towards the southeastern belt star is the nebula M78, which Peterson's Guide, 2nd Ed. describes as a "wispy cloud."

While we're in the vicinity, the Horsehead is just under the southeastern star of the belt. It is smaller, fainter and harder to see than you might think from the many images you've seen. East of Orion's left foot is the Beta star of the dim constellation Monoceros the Unicorn, and just west of that star is a string of Nebulae NGC 2170 and 2183-85. Maybe you can find them or even image them; Peterson's doesn't discuss them. If you can't find Beta mono, it's in the region exactly between Betelgeuse and Sirius, which emerges above the horizon later in the night.

Rigel, Orion's right foot star, seventh brightest in the sky, is a double with a faint companion. West of Rigel is the very faint Witch's Head Nebula. Northwest of Rigel we jump over to the long, winding constellation Eridanus the River, starting at its Beta star and wandering downstream west under Taurus and the tail of Cetus before curving south like a wave, then to the east again before snaking back southwest to end on the early-evening meridian low in the sky. Back at Beta Eri we venture west downriver to encounter Eri Omicron, a widely separated pair of stars on the same level as Rigel. Omicron is actually a triple system only 16 light-years from ours. Following the river, Gamma Eri is southwest of Omicron, and east of it is the planetary nebula NGC 1535; look for two concentric rings, the outer being fainter. An Omicron-to-Gamma distance southwest of Gamma Eri is a group of NGC galaxies, and a bit farther west of these another two that include the brighter galaxy NGC 1300, a barred spiral. 1300 is just north of a fainter Eridanus star marked Tau4 in Peterson's Chart 34. Peterson's Chart 23 shows the Beta and Omicron stars of Eridanus, with a bit more on Chart 35 and most of the remaining loops of this twisting constellation on Chart 34, and the very end down on Chart 46. There is a cluster of galaxies just west of the 'g' star on Chart 34 (Eridanus is so long that they ran out of Greek letters for the stars) if you can find it, 15 degrees east-southeast of Beta Fornax.

And remember, if you can't find any of these faint, far-away southern objects, there's always unmistakable Jupiter to look at in the south half of the sky. And after midnight Saturn rises, earlier as the month progresses. Mars, being overtaken by the speeding Earth, rises at 10pm, and despite the fact that opposition is approaching in March, isn't too big, about a quarter the size of Jupiter. The War God always seems to be hanging out with Venus in the paintings of the Renaissance. The result of this dalliance is Cupid, who gets his cuddliness from her and his toy bow-and-arrows from his dad. The Goddess of Beauty, Peace and Love herself rises higher into the evening sky displaying a waning gibbous phase as she overtakes the Earth. Then there are the Solar System leftovers called the Quarantids, a meteor swarm, coming along on Jan. 3, radiating out of northern Boötes. Which reminds us: wear booties on these cold, long and often clear Winter nights.

- Dennis Cochran

SOME NOTABLE CELESTIAL OBJECTS THIS MONTH

Description RA DEC Constellation M31 - Andromeda Galaxy 0h 42.7m +41° 16'   Andromeda M76 - Little Dumbbell, planetary nebula 1h 42.4m 51° 34'   Perseus NGC 1333 - Reflection Nebula 3h 29.2m 31° 25'    Perseus M42/43 - Orion Nebula 5h 35.4m -5° 27'    Orion M35 - Open Cluster (look for NGC 2158) 6h 08.9m 24° 20'    Gemini M46 - Open Cluster with planetary nebula 7h 41.8m -14° 49'    Puppis   RA/DEC for brightest of multiple objects/td>

References: Observers Handbook 2010, Sky & Telescope and Astronomy magazines - Selected by D.M. Dodge

Comets and Other Special Celestial Events

Bright Comets in 2011:

C/2009 P1 ( Garradd ) - http://www.aerith.net/comet/catalog/2009P1/2009P1.html
103P/Hartley 2 (2010) - http://www.aerith.net/comet/catalog/0103P/2010.html

See Jim Holder's article in the February 2007 Observer for more information about locating comets.