The new moon is December 1st. The waxing crescent moon is below Venus on December 4th. The waxing crescent passes Saturn in the south on December 7th, and is first quarter on December 8th. The full moon, the Yule moon, is north of Jupiter on December 15th. The moon just misses Mars, passing its own ˝ degree diameter north of it at 3 a.m. on December 18th. The Winter Solstice, the shortest day, occurs at 4:21 a.m. on December 21st. The last quarter moon is on December 22nd. The waning crescent moon makes a spectacular triangle with Antares and Mercury in the dawn of December 28th. The new moon is December 30th.
Mercury will become visible in the dawn at the end of the month. Venus dominates the SW evening sky, at magnitude -4.2 bright enough to be seen now in broad daylight. Mars is in the morning sky in Cancer, and has a very close encounter with the moon on the morning of December 18th. Jupiter is at its best, reaching opposition on December 7th, rising at sunset and up all night.
Saturn is well up in the south now at sunset, in Aquarius. Here Freddy Bowles captures its rings, now tilted 5 degrees to our line of sight, on October 25th. By January 7th, they will narrow to 4 degrees, and just 3 degrees by January 28th. The rings will be edge on from Earth between March 23rd and May 6th, but it will be lost then in the Sun’s glare or just reappearing in the dawn.
While the naked eye, dark adapted by several minutes away from any bright lights, is a wonderful instrument to stare up into deep space, far beyond our own Milky Way, binoculars are better for spotting specific deep sky objects. For a detailed map of northern hemisphere skies, about November 30th visit the www.skymaps.com site and download the map for December 2024; it will have a more extensive calendar, and list of best objects for the naked eyes, binoculars, and scopes on the back of the map. Also notable is wonderful video exploring the sky, available from Hubble Space Telescope website at: www.hubblesite.org/explore_astronomy/tonights_sky.
Sky & Telescope magazine has breaking news and highlights of the best events for each week at www.skyandtelescope.com/observing/astronomy-podcasts/
The square of Pegasus dominates the western sky. South of it are the watery constellations of Pisces (the fish), Capricorn (Sea Goat), Aquarius (the Water Bearer) with Saturn now, and Cetus (the Whale). Below Aquarius is Fomalhaut, the only first magnitude star of the southern fall sky. It marks the mouth of Pisces Australius, the Southern Fish. If you want an ideal ap for learning the constellations, download "Nocturne" for Apple phones, and mount it on a tripod for 2’ exposures of the sky, which you can then annotate with star names, constellation lines, and even the mythological figures. Makes the sky come alive.
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. 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 Pleiades, but about half their distance. Their appearance in November in classical times was associated with the stormy season, when frail sailing ships stayed in port. Aldebaran is not a member of the Hyades, but about twice as close as the Hyades; distances in astronomy can be deceiving. Usually the brighter objects are closer, but exceptionally luminous objects, like Rigel in Orion, may be over 2,000 light years distant yet still first magnitude.
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. 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. UWF alumni 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. This wide angle shot, with my Dwarf Labs scope ($450) also captures a geosynchronous satellite just above the nebulae. While it appears the satellite is moving, relative to US, it is stationary. Our own rotation is carrying the nebula westward during this five-minute exposure. The scope is tracking the stars!
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 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.
