Post by Dave Mitsky on Dec 1, 2015 4:23:58 GMT
December Celestial Calendar
All times, unless otherwise noted, are UT (subtract five hours and, when appropriate, one calendar day for EST)
12/3 Last Quarter Moon occurs at 7:40
12/4 Jupiter is 1.8 degrees north of the Moon at 6:00; the Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to occur at 19:08
12/5 The Moon is at apogee, subtending 29'46" from a distance of 404,800 kilometers (251,531 miles), at 14:57
12/6 Mars is 0.1 degree north of the Moon, with an occultation visible from Australia, Indonesia, far southern India, the southern Arabian peninsula, and central and eastern Africa, at 3:00
12/7 Venus is 0.7 degree south of the Moon, with an occultation visible from the Caribbean, Central America, and North America, at 17:00
12/8 The earliest sunset of the year at 40 degrees north latitude occurs today
12/9 Asteroid 16 Psyche (magnitude +9.4) is at opposition at 14:28
12/10 New Moon (lunation 1150) occurs at 10:29
12/14 The peak of the Geminid meteor shower (100 to 120 per hour) occurs at 18:00
12/15 Mercury is at its greatest heliocentric latitude south today
12/17 Neptune is 3 degrees south of the Moon at 8:00
12/18 The Lunar X (the Purbach or Werner Cross), an X-shaped clair-obscure illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to occur at 8:14; First Quarter Moon occurs at 15:14
12/20 Venus is at its greatest heliocentric latitude north today; Uranus is 1.2 degrees north of the Moon, with an occultation visible from the Falkland Islands, the southern tip of South America, and the Antarctic Peninsula, at 1:00
12/21 The Moon is at perigee, subtending 32'18" from a distance of 368,417 kilometers (228,924 miles), at 8:54
12/22 The shortest day of the year at 40 degrees north latitude occurs today; winter solstice in the northern hemisphere occurs at 4:48
12/23 The peak of the Ursid meteor shower (10 per hour) occurs at 2:00; the Moon is 0.6 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation visible from northern Asia, Russia, Europe, northwestern Africa, and the eastern coast of Canada, at 20:00
12/25 Asteroid 27 Euterpe (magnitude +8.4) is at opposition at 5:36; Full Moon (known as the Before Yule, Cold, Long Nights, and Oak Moon) occurs at 11:11
12/26 Uranus is stationary at 11:00
12/29 Mercury is at greatest eastern elongation (20 degrees) at 3:00
12/31 Jupiter is 1.5 degrees north of the Moon at 18:00
Tycho Brahe, Johannes Kepler, Isaac Newton, and Arthur Eddington were born in December.
Giovanni Cassini discovered the Saturnian satellite Rhea on December 23, 1672.
December 14th’s Geminid meteor shower is not affected by moonlight this year. The Geminids, which are associated with the Palladian asteroid, or possible cometary nucleus, 3200 Phaethon, have become the most reliable meteor shower of the year. Geminid meteors appear to originate from a radiant that’s just northwest of Castor (Alpha Geminorum). That radiant lies almost at the zenith at 2:00 a.m. local time. An article on the 2015 Geminids appears on page 44 of the December issue of Sky & Telescope. The Ursids, a normally minor meteor shower, peak on the evening of December 22nd DST. Moonlight from a waxing gibbous Moon will interfere with observing the shower. The radiant is located close to Kochab (Beta Ursa Minoris), some 15 degrees from the north celestial pole. See in-the-sky.org/news.php?id=20151214_11_100 and www.imo.net/calendar/2015#gem for additional information on the Geminids and in-the-sky.org/news.php?id=20151222_11_100 and www.imo.net/calendar/2015#urs for more on the Ursids.
Information on Iridium flares and passes of the ISS, the Tiangong-1, the X-37B, the HST, and other satellites can be found at www.heavens-above.com/
The Moon is 19.3 days old, is illuminated 72.1%, and is located in Cancer on December 1st at 0:00 UT. Due to the position of the ecliptic, the Moon reaches its highest point in the sky for the year in December. It attains its greatest northern declination (+18.4 degrees) for the month on December 25th and its greatest southern declinations (-18.4 degrees) on December 12th. Longitudinal libration is at a maximum of +5.5 degrees on December 27th and a minimum of -4.8 degrees on December 12th. Latitudinal libration is at a maximum of +6.5 degrees on December 24th and a minimum of -6.6 degrees on December 12th. The Moon occults Mars on December 6h, Uranus on December 20th, and the first-magnitude star Aldebaran on December 23rd from certain parts of the world. Consult www.lunar-occultations.com/iota/iotandx.htm for more on these events. The 13%-illuminated Moon occults Venus, which will be 17 arc seconds in angular size and illuminated 69%, on the afternoon of December 7th. For further information on this daytime event, see www.lunar-occultations.com/iota/planets/1207venus.htm and pages 46 and 47 of the December issue of Sky & Telescope. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons and www.curtrenz.com/moon.html for Full Moon data. Times and dates for the lunar light rays predicted to occur this month are available at www.lunar-occultations.com/rlo/rays/rays.htm
The Sun is located in Ophiuchus, a non-traditional constellation of the zodiac, on December 1st. Winter solstice for the northern hemisphere occurs when the Sun is farthest south for the year on December 22nd UT.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on December 1st: Mercury (magnitude -0.8, 4.7", 98% illuminated, 1.42 a.u., Ophiuchus), Venus (magnitude -4.2, 17.4", 67% illuminated, 0.96 a.u., Virgo), Mars (magnitude +1.5, 4.8", 93% illuminated, 1.97 a.u., Virgo), Jupiter (magnitude -2.0, 35.6", 99% illuminated, 5.54 a.u., Leo), Saturn (magnitude +0.4, 15.1", 100% illuminated, 10.99 a.u., Ophiuchus), Uranus (magnitude +5.8, 3.6", 100% illuminated, 19.57 a.u. on December 16th, Pisces), Neptune (magnitude +7.9, 2.3", 100% illuminated, 30.22 a.u. on December 16th, Aquarius), and Pluto (magnitude +14.2, 0.1", 100% illuminated, 33.92 a.u. on December 16th, Sagittarius).
During the evening, Mercury can be found in the southwest, Uranus in the southeast, and Neptune in the south. Jupiter is the east and Uranus is in the west at midnight. In the morning, Venus, Mars, and Saturn are located in the southeast and Jupiter is located in the south.
At midmonth, Mercury is visible during evening twilight, Venus rises at 4:00 a.m. local time, Mars rises at 2:00 a.m. local time, Jupiter rises at midnight and transits at 6:00 a.m. local time, and Saturn is visible during morning twilight for observers at latitude 40 degrees north.
Mercury is visible low in the southwestern evening sky from December 7th through December 31st. It’s at its greatest heliocentric latitude south on December 15th. Greatest eastern elongation takes place on December 29th UT. Mercury sets about an hour after the Sun on that date.
Venus is occulted by the waning gibbous Moon during daylight on the afternoon of December 7th. The brightest planet crosses into Libra on December 11th. Venus is at its greatest heliocentric latitude north on December 15th. It lies two degrees north of the third-magnitude star Zubenelgenubi (Alpha Librae) on December 17th.
Mars is occulted by the Moon on December 6th. The Red Planet is four degrees north of the first-magnitude star Spica on December 21st.
In early December, Jupiter rises at approximately 12:30 a.m. local time. The gas giant is 1.8 degrees north of the Moon on December 4th. By the end of the month, Jupiter rises around 11:30 p.m. local time. It shines at magnitude -2.2 and spans nearly 39 arc seconds at that time. Click on
www.skyandtelescope.com/observing/interactive-sky-watching-tools/ or consult page 52 of the December issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot. Data on Galilean satellite events is available at www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and on page 47 of the December issue of Sky & Telescope.
Saturn reappears low in the morning sky in mid-December. The Ringed Planet is situated a bit more than six degrees to the north of the first-magnitude star Antares on December 21st. For information on Saturn’s bright satellites, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
Uranus is located two degrees due south of the fourth-magnitude star Epsilon Piscium for the entire month. It is occulted by the Moon on December 20th. Uranus is stationary and then resumes direct or prograde (eastern) motion on December 26th.
Neptune lies 1.5 degrees northeast of the fifth-magnitude star Sigma Aquarii on December 1st and 2.0 degrees northeast of that star on December 31st. The eighth planet sets before 9:00 p.m. local time by the end of the month.
See www.curtrenz.com/uranep.html for additional information on Uranus and Neptune.
Finder charts for Uranus and Neptune can be found on page 49 of the September issue of Sky & Telescope and online at www.nakedeyeplanets.com/uranus.htm and www.nakedeyeplanets.com/neptune.htm and at www.skyandtelescope.com/wp-content/uploads/WEB_UrNep_Finders.pdf
Click on www.skyandtelescope.com/observing/interactive-sky-watching-tools/ for JavaScript utilities that will illustrate the positions of the five brightest satellites of Uranus and the position of Triton, Neptune’s brightest satellite.
The dwarf planet Pluto will not be visible again until next year.
For more on the planets and how to locate them, see www.nakedeyeplanets.com/
Comet C/2013 US10 (Catalina) may shine at fourth magnitude in early December as it travels northward through Virgo and eventually through Bootes. A finder chart appears on page 45 of the December issue of Sky & Telescope. Comet Catalina lies just south of Arcturus on the morning of December 31st. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html for additional information on comets that are visible this month.
During December, asteroid 29 Laetitia glides northwestward through Cetus. The tenth-magnitude minor planet lies very close to the spiral galaxy M77 on the nights of December 9th and December 10th. On the night of December 16th, it passes between the spiral galaxy NGC 1055 and the fourth-magnitude star Delta Cygni. The following asteroids brighter than magnitude +11.0 reach opposition this month: 16 Psyche (magnitude +9.6) on December 9th and 27 Euterpe (magnitude +8.4) in on December 25th. For information on this year’s bright asteroids and upcoming asteroid occultation events, consult www.curtrenz.com/asteroids.html and asteroidoccultation.com/ respectively.
A wealth of information on solar system celestial bodies is posted at www.curtrenz.com/astronomy.html and nineplanets.org/
Free star maps for December can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from +2.1 to +3.4, on December 3rd, 6th, 9th, 12th, 15th, 18th, 21st, 23rd, 26th, and 29th. On December 17th (December 18th UT), Algol is at minimum brightness and is well-placed in the first half of the night for observers in North America. Consult page 47 of the December issue of Sky & Telescope for the times of the eclipses. For more on Algol, see stars.astro.illinois.edu/sow/Algol.html and www.solstation.com/stars2/algol3.htm
Information on observing some of the more prominent Messier galaxies can be found at www.cloudynights.com/topic/358295-how-to-locate-some-of-the-major-messier-galaxies-and-helpful-advice-for-novice-amateur-astronomers/
Deep-sky object list generators can be found at www.virtualcolony.com/sac/ and tonightssky.com/MainPage.php
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)
Notable carbon star for December: U Camelopardalis
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 1042, 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 (Fornax I Galaxy Cluster), 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 (Perseus I Galaxy Cluster), 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)
Top ten binocular deep-sky objects for December: M34, M45, Mel15, Mel20, NGC 869, NGC 884, NGC 1027, NGC 1232, St2, St23
Top ten deep-sky objects for December: M34, M45, M77, NGC 869, NGC 884, NGC 891, NGC 1023, NGC 1232, NGC 1332, NGC 1360
Challenge deep-sky object for December: vdB14 (Camelopardalis)
The objects listed above are located between 2:00 and 4:00 hours of right ascension.
All times, unless otherwise noted, are UT (subtract five hours and, when appropriate, one calendar day for EST)
12/3 Last Quarter Moon occurs at 7:40
12/4 Jupiter is 1.8 degrees north of the Moon at 6:00; the Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to occur at 19:08
12/5 The Moon is at apogee, subtending 29'46" from a distance of 404,800 kilometers (251,531 miles), at 14:57
12/6 Mars is 0.1 degree north of the Moon, with an occultation visible from Australia, Indonesia, far southern India, the southern Arabian peninsula, and central and eastern Africa, at 3:00
12/7 Venus is 0.7 degree south of the Moon, with an occultation visible from the Caribbean, Central America, and North America, at 17:00
12/8 The earliest sunset of the year at 40 degrees north latitude occurs today
12/9 Asteroid 16 Psyche (magnitude +9.4) is at opposition at 14:28
12/10 New Moon (lunation 1150) occurs at 10:29
12/14 The peak of the Geminid meteor shower (100 to 120 per hour) occurs at 18:00
12/15 Mercury is at its greatest heliocentric latitude south today
12/17 Neptune is 3 degrees south of the Moon at 8:00
12/18 The Lunar X (the Purbach or Werner Cross), an X-shaped clair-obscure illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to occur at 8:14; First Quarter Moon occurs at 15:14
12/20 Venus is at its greatest heliocentric latitude north today; Uranus is 1.2 degrees north of the Moon, with an occultation visible from the Falkland Islands, the southern tip of South America, and the Antarctic Peninsula, at 1:00
12/21 The Moon is at perigee, subtending 32'18" from a distance of 368,417 kilometers (228,924 miles), at 8:54
12/22 The shortest day of the year at 40 degrees north latitude occurs today; winter solstice in the northern hemisphere occurs at 4:48
12/23 The peak of the Ursid meteor shower (10 per hour) occurs at 2:00; the Moon is 0.6 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation visible from northern Asia, Russia, Europe, northwestern Africa, and the eastern coast of Canada, at 20:00
12/25 Asteroid 27 Euterpe (magnitude +8.4) is at opposition at 5:36; Full Moon (known as the Before Yule, Cold, Long Nights, and Oak Moon) occurs at 11:11
12/26 Uranus is stationary at 11:00
12/29 Mercury is at greatest eastern elongation (20 degrees) at 3:00
12/31 Jupiter is 1.5 degrees north of the Moon at 18:00
Tycho Brahe, Johannes Kepler, Isaac Newton, and Arthur Eddington were born in December.
Giovanni Cassini discovered the Saturnian satellite Rhea on December 23, 1672.
December 14th’s Geminid meteor shower is not affected by moonlight this year. The Geminids, which are associated with the Palladian asteroid, or possible cometary nucleus, 3200 Phaethon, have become the most reliable meteor shower of the year. Geminid meteors appear to originate from a radiant that’s just northwest of Castor (Alpha Geminorum). That radiant lies almost at the zenith at 2:00 a.m. local time. An article on the 2015 Geminids appears on page 44 of the December issue of Sky & Telescope. The Ursids, a normally minor meteor shower, peak on the evening of December 22nd DST. Moonlight from a waxing gibbous Moon will interfere with observing the shower. The radiant is located close to Kochab (Beta Ursa Minoris), some 15 degrees from the north celestial pole. See in-the-sky.org/news.php?id=20151214_11_100 and www.imo.net/calendar/2015#gem for additional information on the Geminids and in-the-sky.org/news.php?id=20151222_11_100 and www.imo.net/calendar/2015#urs for more on the Ursids.
Information on Iridium flares and passes of the ISS, the Tiangong-1, the X-37B, the HST, and other satellites can be found at www.heavens-above.com/
The Moon is 19.3 days old, is illuminated 72.1%, and is located in Cancer on December 1st at 0:00 UT. Due to the position of the ecliptic, the Moon reaches its highest point in the sky for the year in December. It attains its greatest northern declination (+18.4 degrees) for the month on December 25th and its greatest southern declinations (-18.4 degrees) on December 12th. Longitudinal libration is at a maximum of +5.5 degrees on December 27th and a minimum of -4.8 degrees on December 12th. Latitudinal libration is at a maximum of +6.5 degrees on December 24th and a minimum of -6.6 degrees on December 12th. The Moon occults Mars on December 6h, Uranus on December 20th, and the first-magnitude star Aldebaran on December 23rd from certain parts of the world. Consult www.lunar-occultations.com/iota/iotandx.htm for more on these events. The 13%-illuminated Moon occults Venus, which will be 17 arc seconds in angular size and illuminated 69%, on the afternoon of December 7th. For further information on this daytime event, see www.lunar-occultations.com/iota/planets/1207venus.htm and pages 46 and 47 of the December issue of Sky & Telescope. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons and www.curtrenz.com/moon.html for Full Moon data. Times and dates for the lunar light rays predicted to occur this month are available at www.lunar-occultations.com/rlo/rays/rays.htm
The Sun is located in Ophiuchus, a non-traditional constellation of the zodiac, on December 1st. Winter solstice for the northern hemisphere occurs when the Sun is farthest south for the year on December 22nd UT.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on December 1st: Mercury (magnitude -0.8, 4.7", 98% illuminated, 1.42 a.u., Ophiuchus), Venus (magnitude -4.2, 17.4", 67% illuminated, 0.96 a.u., Virgo), Mars (magnitude +1.5, 4.8", 93% illuminated, 1.97 a.u., Virgo), Jupiter (magnitude -2.0, 35.6", 99% illuminated, 5.54 a.u., Leo), Saturn (magnitude +0.4, 15.1", 100% illuminated, 10.99 a.u., Ophiuchus), Uranus (magnitude +5.8, 3.6", 100% illuminated, 19.57 a.u. on December 16th, Pisces), Neptune (magnitude +7.9, 2.3", 100% illuminated, 30.22 a.u. on December 16th, Aquarius), and Pluto (magnitude +14.2, 0.1", 100% illuminated, 33.92 a.u. on December 16th, Sagittarius).
During the evening, Mercury can be found in the southwest, Uranus in the southeast, and Neptune in the south. Jupiter is the east and Uranus is in the west at midnight. In the morning, Venus, Mars, and Saturn are located in the southeast and Jupiter is located in the south.
At midmonth, Mercury is visible during evening twilight, Venus rises at 4:00 a.m. local time, Mars rises at 2:00 a.m. local time, Jupiter rises at midnight and transits at 6:00 a.m. local time, and Saturn is visible during morning twilight for observers at latitude 40 degrees north.
Mercury is visible low in the southwestern evening sky from December 7th through December 31st. It’s at its greatest heliocentric latitude south on December 15th. Greatest eastern elongation takes place on December 29th UT. Mercury sets about an hour after the Sun on that date.
Venus is occulted by the waning gibbous Moon during daylight on the afternoon of December 7th. The brightest planet crosses into Libra on December 11th. Venus is at its greatest heliocentric latitude north on December 15th. It lies two degrees north of the third-magnitude star Zubenelgenubi (Alpha Librae) on December 17th.
Mars is occulted by the Moon on December 6th. The Red Planet is four degrees north of the first-magnitude star Spica on December 21st.
In early December, Jupiter rises at approximately 12:30 a.m. local time. The gas giant is 1.8 degrees north of the Moon on December 4th. By the end of the month, Jupiter rises around 11:30 p.m. local time. It shines at magnitude -2.2 and spans nearly 39 arc seconds at that time. Click on
www.skyandtelescope.com/observing/interactive-sky-watching-tools/ or consult page 52 of the December issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot. Data on Galilean satellite events is available at www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and on page 47 of the December issue of Sky & Telescope.
Saturn reappears low in the morning sky in mid-December. The Ringed Planet is situated a bit more than six degrees to the north of the first-magnitude star Antares on December 21st. For information on Saturn’s bright satellites, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
Uranus is located two degrees due south of the fourth-magnitude star Epsilon Piscium for the entire month. It is occulted by the Moon on December 20th. Uranus is stationary and then resumes direct or prograde (eastern) motion on December 26th.
Neptune lies 1.5 degrees northeast of the fifth-magnitude star Sigma Aquarii on December 1st and 2.0 degrees northeast of that star on December 31st. The eighth planet sets before 9:00 p.m. local time by the end of the month.
See www.curtrenz.com/uranep.html for additional information on Uranus and Neptune.
Finder charts for Uranus and Neptune can be found on page 49 of the September issue of Sky & Telescope and online at www.nakedeyeplanets.com/uranus.htm and www.nakedeyeplanets.com/neptune.htm and at www.skyandtelescope.com/wp-content/uploads/WEB_UrNep_Finders.pdf
Click on www.skyandtelescope.com/observing/interactive-sky-watching-tools/ for JavaScript utilities that will illustrate the positions of the five brightest satellites of Uranus and the position of Triton, Neptune’s brightest satellite.
The dwarf planet Pluto will not be visible again until next year.
For more on the planets and how to locate them, see www.nakedeyeplanets.com/
Comet C/2013 US10 (Catalina) may shine at fourth magnitude in early December as it travels northward through Virgo and eventually through Bootes. A finder chart appears on page 45 of the December issue of Sky & Telescope. Comet Catalina lies just south of Arcturus on the morning of December 31st. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html for additional information on comets that are visible this month.
During December, asteroid 29 Laetitia glides northwestward through Cetus. The tenth-magnitude minor planet lies very close to the spiral galaxy M77 on the nights of December 9th and December 10th. On the night of December 16th, it passes between the spiral galaxy NGC 1055 and the fourth-magnitude star Delta Cygni. The following asteroids brighter than magnitude +11.0 reach opposition this month: 16 Psyche (magnitude +9.6) on December 9th and 27 Euterpe (magnitude +8.4) in on December 25th. For information on this year’s bright asteroids and upcoming asteroid occultation events, consult www.curtrenz.com/asteroids.html and asteroidoccultation.com/ respectively.
A wealth of information on solar system celestial bodies is posted at www.curtrenz.com/astronomy.html and nineplanets.org/
Free star maps for December can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from +2.1 to +3.4, on December 3rd, 6th, 9th, 12th, 15th, 18th, 21st, 23rd, 26th, and 29th. On December 17th (December 18th UT), Algol is at minimum brightness and is well-placed in the first half of the night for observers in North America. Consult page 47 of the December issue of Sky & Telescope for the times of the eclipses. For more on Algol, see stars.astro.illinois.edu/sow/Algol.html and www.solstation.com/stars2/algol3.htm
Information on observing some of the more prominent Messier galaxies can be found at www.cloudynights.com/topic/358295-how-to-locate-some-of-the-major-messier-galaxies-and-helpful-advice-for-novice-amateur-astronomers/
Deep-sky object list generators can be found at www.virtualcolony.com/sac/ and tonightssky.com/MainPage.php
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)
Notable carbon star for December: U Camelopardalis
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 1042, 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 (Fornax I Galaxy Cluster), 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 (Perseus I Galaxy Cluster), 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)
Top ten binocular deep-sky objects for December: M34, M45, Mel15, Mel20, NGC 869, NGC 884, NGC 1027, NGC 1232, St2, St23
Top ten deep-sky objects for December: M34, M45, M77, NGC 869, NGC 884, NGC 891, NGC 1023, NGC 1232, NGC 1332, NGC 1360
Challenge deep-sky object for December: vdB14 (Camelopardalis)
The objects listed above are located between 2:00 and 4:00 hours of right ascension.