December 2005 Calendar by Dave Mitsky

All times are UT (subtract 5 hours and when appropriate 1 calendar day for EST)

12/1 New Moon (lunation 1026) occurs at 15:01
12/2 A maximum lunar libration of 7.3 degrees occurs at 3:00
12/4 Mercury is stationary at 1:00; Venus is 2 degrees north of the Moon at 18:00
12/5 The Moon is at perigee, subtending 32'32" from a distance of 367,364 km, at 4:33
12/6 Neptune is 4 degrees north of the Moon at 3:00
12/7 Mercury is at its greatest heliocentric latitude north; Uranus is 2 degrees north of the Moon at 16:00
12/8 Venus attains its greatest illuminated extent of 348 square arc seconds; First Quarter Moon occurs at 9:36
12/9 A minimum lunar libration of 4.0 degrees occurs at 5:00; asteroid 3 Juno (magnitude 7.6) is at opposition at 8:00; Venus achieves its greatest brilliancy (magnitude -4.7) at 13:00
12/10 Mars is stationary at 23:00
12/12 Mars is 1.3 degrees south of the Moon at 5:00 - an occultation is visible in northeast Siberia; Mercury is at greatest western elongation (21 degrees) at 13:00
12/13 Mercury attains its greatest illuminated extent of 22 square arc seconds; the Moon is 0.3 degrees south of the bright open star cluster M45 (the Pleiades) at 20:00
12/14 The peak of the moonlight compromised Geminid meteor shower (only 10-20/hour due to moonlight) occurs at 4:00
12/15 The Galilean satellite Ganymede emerges from eclipse at 10:19; Full Moon (known as the Cold, Oak, Before Yule or Long Nights Moon) occurs at 16:15; a maximum lunar libration of 7.7 degrees occurs at 23:00
12/16 Pluto is in conjunction with the Sun at 4:00
12/19 The star SAO 98190 (magnitude 7.2) passes 1.6' north of Titan (magnitude 8.2); Saturn is 4 degrees south of the Moon at 9:00
12/20 Mercury (magnitude -0.6) is 6 degrees north of the first magnitude star Antares at 6:00
12/21 The Moon is at apogee, subtending 29'30" from a distance of 405,014 km, at 3:00; the winter solstice occurs at 18:35
12/22 Venus is at the ascending node; a minimum lunar libration of 3.8 degrees occurs at 8:00; the Ursid meteor shower (5-10/hour) peaks at 13:00
12/23 Venus is stationary at 5:00; Last Quarter Moon occurs at 19:36
12/24 Asteroid 4 Vesta (magnitude 6.6) is 6' south of Delta Geminorum at 16:00; the Galilean satellites Io, Europa, and Callisto form a compact grouping, an event that is visible in Australia and Japan, from 17:54 to 19:22
12/25 The Moon is 0.9 degrees north of the first magnitude star Spica at 14:00 - an occultation is visible in most of North America, Central America, the Caribbean, and the northernmost portion of South America
12/27 Jupiter is 4 degrees north of the Moon at 4:00
12/28 Asteroid 1 Ceres is in conjunction with the Sun at 12:00; a maximum lunar libration of 8.3 degrees occurs at 21:00
12/29 The Moon is 0.2 degree north of Antares at 2:00 - an occultation is visible in India, southeast Asia, Indonesia, the Philippines, northern Australia, and some south Pacific islands; Callisto is the only Galilean satellite visible at 22:00
12/30 Mercury is at its descending node; Mercury is 5 degrees north of the Moon at 0:00
12/31 New Moon (lunation 1027) occurs at 3:12

Times and dates for the lunar light rays predicted to occur this month are available at http://www.lunar-occultations.com/rlo/rays/rays.htm

The planets on December 1: Mercury (not visible, 9.0", 16% illuminated), Venus (-4.6 magnitude, 35.9", 33% illuminated), Mars (-1.6 magnitude, 16.9", 97% illuminated), Jupiter (- 1.7 magnitude, 31.4", 100% illuminated), Saturn ( 0.2 magnitude, 19.2", 100% illuminated), Uranus (5.9 magnitude, 3.4", 100% illuminated), Neptune (8.0 magnitude, 2.2", 100% illuminated), and Pluto (14.0 magnitude, 0.1", 100% illuminated).

The year's best apparition of Mercury occurs on December 12 when the speedy planet rises almost 2 hours before the Sun.

Venus grows in apparent size but becomes an increasingly thin crescent. It reaches maximum brightness on December 9 and has a close rendezvous with a 15 per cent illuminated Moon on the evening of December 4.

Located in Aries, Mars is still brighter than Sirius on December 1 but fades by a full magnitude during December. Syrtis Major is well placed for early evening observers in the early part of the month, Mare Sirenum at mid-month, and Solis Lacus in the latter part of December.

Jupiter is visible by 3:00 a.m. by month's end. It grows closer to Zubenelgenubi in Libra and is only 2 degrees to its northwest on December 31.

Saturn is located in Cancer. It rises sometime after 8:00 p.m. EST. On the nights of December 1 and 2, Saturn's seven brightest satellites appear in the vicinity of the planet's disk.

Uranus can be found in Aquarius in the early evening, nearly midway between the stars Lambda and Sigma.

Neptune is located close to Theta Capricorni but will become increasingly difficult to see as the month passes.

Pluto is not visible this month.

The seventh magnitude asteroid 4 Vesta can be found just 11' to the north of NGC 2392 (the Eskimo Nebula) on the evening of December 13. It passes even closer to 63 Geminorum (magnitude 5.2) on December 15 and Delta Geminorum (magnitude 3.5) on December 24 as it tracks northwestward.

Comet C/2005 E2 (McNaught) travels northeastward through Capricornus this month. The tenth magnitude comet is situated just to the north of the fourth magnitude star Iota Capricorni on the evening of December 17.

One hundred and five binary and multiple stars for December: Gamma Andromedae, 59 Andromedae, Struve 245 (Andromeda); Struve 362, Struve 374, Struve 384, Struve 390, Struve 396, Struve 400, Struve 419, Otto Struve 67 (Camelopardalis); Struve 191, Struve Iota Cassiopeiae, Struve 263, Otto Struve 50, Struve 283, Struve 284 (Cassiopeia); 61 Ceti, Struve 218, Omicron Ceti, Struve 274, Nu Ceti, h3511, 84 Ceti, h3524, Lambda Ceti, Struve 330 (Cetus); h3527, h3533, Theta Eridani, Rho Eridani, Struve 341, h3548, h3565, Tau-4 Eridani, Struve 408, Struve 411, h3589, h3601, 30 Eridani, 32 Eridani (Eridanus); h3478, h3504, Omega Fornacis, Eta-2 Fornacis, Alpha Fornacis, See 25, Xi-3 Fornacis, h3596 (Fornax); Struve 268, Struve 270, h1123, Otto Struve 44, h2155, Nu Persei, Struve 297, Struve 301, Struve 304, Eta Persei, Struve 314, Otto Struve 48, Tau Persei, Struve 331, Struve 336, Es588, Struve 352, Struve 360, Struve 369, Struve 382, Struve 388, Struve 392, Struve 410, Struve 413, Struve 425, Otto Struve 59, Struve 426, 40 Persei, Struve 434, Struve 448, Es277, Zeta Persei, Struve 469, Epsilon Persei, Es878 (Perseus); Struve 399, Struve 406, Struve 401, Struve 422, Struve 430, Struve 427, Struve 435, 30 Tauri (Taurus); Epsilon Trianguli, Struve 219, Iota Trianguli, Struve 232, Struve 239, Struve 246, 10 Trianguli, Struve 269, h653, 15 Trianguli, Struve 285, Struve 286, Struve 310 (Triangulum)

Challenge binary star for December: 48 Cassiopeiae (Cassiopeia)

One hundred deep-sky objects for December: NGC 891 (Andromeda); IC 342, K6, St23, Tom 5 (Camelopardalis); Be65, IC 1848, K4, Mel15, NGC 896, NGC 1027, St2, Tr3 (Cassiopeia); M77, NGC 788, NGC 835, NGC 864, NGC 908, NGC 936, NGC 955, NGC 958, NGC 1015, NGC 1016, NGC 1022, NGC 1035, NGC 1052, NGC 1055, NGC 1087, NGC 1094 (Cetus); IC 2006, NGC 1084, NGC 1140, NGC 1187, NGC 1199, NGC 1209, NGC 1232, NGC 1291, NGC 1300, NGC 1309, NGC 1332, NGC 1337, NGC 1353, NGC 1357, NGC 1395, NGC 1400, NGC 1407, NGC 1421, NGC 1426, NGC 1440, NGC 1452, NGC 1453, NGC 1461 (Eridanus); NGC 1079, NGC 1097, NGC 1201, NGC 1292, NGC 1316, NGC 1317, NGC 1326, NGC 1344, NGC 1350, NGC 1360, NGC 1365, NGC 1371, NGC 1374, NGC 1379, NGC 1380, NGC 1381, NGC 1387, NGC 1398, NGC 1404, NGC 1406, NGC 1425 (Fornax); Bas10, Cz8, IC 351, IC 2003, K5, Mel 20, M34, NGC 869, NGC 884, NGC 957, NGC 1023, NGC 1058, NGC 1161, NGC 1245, NGC 1275, NGC 1333, NGC 1342, NGC 1444, Tr2 (Perseus); M45 (Taurus); NGC 777, NGC 784, NGC 890, NGC 925, NGC 949, NGC 959, NGC 978A/B (Triangulum)

Challenge deep-sky object for December: vdB14 (Camelopardalis)

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