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The Night Sky of January

Dr. Wayne Wooten
Professor of Astronomy

For January 2013, the Moon will be last quarter on January 4th. It will interfere somewhat with the peak for Quadrantid Meteor Shower on the same morning, with perhaps 30 meteors per hour coming out of the NE in the morning sky. The first two weeks find the moon waning in the morning sky. The waning crescent moon passes 4 degrees south of Saturn on January 6thnd. The waning crescent moon is hard to see passing just 3 degrees north of Venus in the dawn on January 10th. The new moon is on January 11th. The waxing crescent moon might be spotted 6 degrees north of Mars on January 13th, but this will be your last glimpse of the red planet for months, if you can still pick it out of the twilight. The first quarter moon is on January 18th, and the waxing gibbous moon passes in front of Jupiter on January 21, if you live farther south than West Florida. Here we see a very close miss! The full moon falls on January 26th, for northern Indian tribes, this was the Wolf or Snow Moon….before global warning, obviously….

Venus disappears behind the sun by the end of January, but can still be glimpsed just before dawn in first weeks of January. Mars too is getting lost behind the Sun. Mercury also is not well placed for viewing this month. So its up to the big jovians to supply our planetary thrills in January. Jupiter is still well placed in the souther sky through April, and its four moons and their transits across his face a fine telescopic treat for all observers and star gazes. It sits in the horns of Taurus the Bull for the next several months. Saturn rises about 2 AM as January begins, and will reach opposition on April 25th this year. It will be in the faint constellation Libra all year.

The square of Pegasus dominates the western sky. The constellation Cassiopeia makes a striking W in the NW. She contains many nice star clusters for binocular users in her outer arm of our Milky Way, extending to the NE now. Her daughter, Andromeda, starts with the NE corner star of Pegasus’’ Square, and goes NE with two more bright stars in a row. It is from the middle star, beta Andromeda, that we proceed about a quarter the way to the top star in the W of Cassiopeia, and look for a faint blur with the naked eye. M-31, the Andromeda Galaxy, is the most distant object visible with the naked eye, lying about 2.5 million light years distant. Overhead is Andromeda’s hero, Perseus, rises. Between him and Cassiopeia is the fine Double Cluster, faintly visible with the naked eye and two fine binocular objects in the same field. Perseus contains the famed eclipsing binary star Algol, where the Arabs imagined the eye of the gorgon Medusa would lie. It fades to a third its normal brightness for six out of every 70 hours, as a larger but cooler orange giant covers about 80% of the smaller but hotter and thus brighter companion as seen from Earth.

Look at Perseus’ feet for the famed Pleiades cluster; they lie about 400 light years distant, and over 250 stars are members of this fine group. East of the seven sisters is the V of stars marking the face of Taurus the Bull, with bright orange Aldebaran as his eye. The V of stars is the Hyades cluster, older than the blue Pleaides, but about half their distance. Yellow Capella, a giant star the same temperature and color as our much smaller Sun, dominates the overhead sky. It is part of the pentagon on stars making up Auriga, the Charioteer (think Ben Hur). Several nice binocular Messier open clusters are found in the winter milky way here. East of Auriga, the twins, Castor and Pollux highlight the Gemini. You can associate the pair with Jason and the Golden Fleece legend, for they were the first two Argonauts to sign up on his crew of adventurers.

South of Gemini, Orion is the most familiar winter constellation, dominating the eastern sky at dusk. The reddish supergiant Betelguese marks his eastern shoulder, while blue-white supergiant Rigel stands opposite on his west knee. Just south of the belt, hanging like a sword downward, is M-42, the Great Nebula of Orion, an outstanding binocular and telescopic stellar nursery. It is part of a huge spiral arm gas cloud, with active starbirth all over the place. You should be able to glimpse this stellar birthplace as a faint blur with just your naked eyes! Our highlight photo for January and shows the many colors the camera reveals of this ionized cloud of hot young stars and glowing gases around them.

Last but certainly not least, in the east rise the hunter’s two faithful companions, Canis major and minor. Procyon is the bright star in the little dog, and rises minutes before Sirius, the brightest star in the sky. Sirius dominates the SE sky by 7 PM, and as it rises, the turbulent winter air causes it to sparkle with shafts of spectral fire. Beautiful as the twinkling appears to the naked eye, for astronomers this means the image is blurry; only in space can we truly see "clearly now". At 8 light years distance, Sirius is the closest star we can easily see with the naked eye. Below Sirius in binoculars is another fine open cluster, M-41, a fitting dessert for New Year’s sky feast.

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