December skies of the Gulf Coast
The waning crescent moon is just above Mars in the dawn on Dec. 2 and is new on Dec. 4. The waxing crescent moon is just below Venus in the dusk on Dec. 6. Compare their phases that evening in low-power telescopes. The moon passes beneath Saturn on Dec. 7, and below Jupiter on Dec. 8. It is the first quarter on Dec. 10. The best meteor shower of the year, the Geminid meteor shower, peaks on the morning of Dec. 14, with the best observing after moonset about 3 a.m. Look for a meteor a minute coming out of the northeast. The full moon, the Yule or Long Night Moon, occurs on Dec. 18. The winter solstice, our shortest day, begins at 9:59 a.m. The last quarter moon is on Dec. 26, and on New Year's Eve, the waning crescent moon again returns to the right of Mars.
Primetime of planetary observing is fast ending. All three bright planets now in the west will soon vanish behind the Sun. This is most true of Venus, which overtakes earth this month and gets much larger in the telescope and even binoculars. The phase is 30% lit on Dec. 1, down to 15% by midmonth, down to 10% at Winter Solstice, and down to a mere 5% sliver by New Year. But she has grown to over an arc minute in size, the biggest any planet can appear from Earth. She will be low in the twilight then, and beside Mercury in the dusk on Dec. 30 about 40 minutes after sunset, a fitting ending to the year.
Saturn will be the next to vanish in the Sun’s glare, in January, and Jupiter by Valentine’s Day. As they are low in the southwest, stay to low powers to see the four moons around Jupiter and Saturn’s rings while you can in the telescope.
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, visit Skymaps.com.
The square of Pegasus dominates the western sky. South of it is the watery constellations of Pisces (the fish), Capricorn (Sea-Goat), Aquarius (the Water Bearer), and Cetus (the Whale). Below Aquarius is Fomalhaut, the only first-magnitude star of the southern fall sky. It is the mouth of Pisces Australius, the Southern Fish.
The constellation Cassiopeia makes a striking west in the northwest. She contains many nice star clusters for binocular users in her outer arm of our Milky Way, extending to the northeast now. Her daughter, Andromeda, starts with the northeast corner star of Pegasus’ Square and goes northeast 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 west of Cassiopeia, and look for a faint blur with the naked eye. M-31, the Andromeda Galaxy, is the most distant object visible to the naked eye, lying about 2.5 million light-years distant. It is recorded in Dani Trotman’s Google Pixel 4.5’ tracked exposure with Virtuoso mount.
Overhead is Andromeda’s hero, Perseus, who rises. 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.
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 star birth all over the place. EAAA member Marc Glover took this fine portrait in November with just an 80mm refractor; what detail with such a small scope!
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 southeast sky by 7 p.m., 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. At eight light-years distance, Sirius is the closest star we can easily see with the naked eye from West Florida. You must be in south Florida to spot Alpha Centauri on June evenings. Below Sirius in binoculars is another fine open cluster, M-41, a fitting dessert for New Year’s sky feast.
We have set new dates for our public gazes at Big Lagoon State Park west of Pensacola for these Saturdays: December 11, January 8 and 22, February 5 and 19, March 12 and 26, and April 8 and 23. Be sure to check-in at the gate before sunset.
For more information on the Escambia Amateur Astronomers, visit our website, join us on Facebook, or call our sponsor, Lauren Rogers at Pensacola State College at (850) 484-1155, or e-mail her at email@example.com. All EAAA events are free and open to the public.