Telescope Reviews: January 2008 AstroCalendar

January Calendar by Dave Mitsky

All times are UT (subtract five hours, and one calendar day when appropriate, for EST)

1/1 Asteroid 1 Ceres is stationary today; the periodic comet 8P/Tuttle is at its closest approach to the Earth (0.253 astronomical units) today; Iapetus is less than two planetary diameters north of Saturn at 0:00; a minimum lunar libration of 6.5 degrees occurs at 11:00
1/2 The Earth is at perihelion (147,096,448 kilometers distant from the Sun - 3% closer than at aphelion) at 23:50
1/3 The Moon is at apogee, subtending 29'29" from a distance of 405,331 kilometers, at 8:05
1/4 Mercury is at its greatest heliocentric latitude south today; Comet 8P/Tuttle lies just to the east of the spiral galaxy M74 in Pisces today; the Quadrantid meteor shower (40 or more per hour) peaks at 6:40
1/5 The latest sunrise of 2008 at latitude 40 degrees north occurs today; a maximum lunar libration of 6.8 degrees occurs at 6:00; Venus is 7 degrees north of the Moon at 6:00; the Moon is 0.5 degree south of the first magnitude star Antares (Alpha Scorpii) - an occultation is visible from the southern part of South America and Antarctica - at 10:00
1/7 Venus is 6 degrees north of Antares at 1:00
1/8 The latest onset of morning twilight occurs today; New Moon (lunation 1052) occurs at 11:37
1/10 Asteroid 15 Eunomia (magnitude 8.3) is at opposition today
1/11 Neptune is 0.4 degree north of the Moon - an occultation is visible from New Zealand, the southernmost parts of Australia, and portions of Antarctica - at 1:00; a minimum lunar libration 5.2 degrees occurs at 14:00
1/13 Uranus is 3 degrees south of the Moon at 1:00
1/15 First Quarter Moon occurs at 19:46
1/17 A maximum lunar libration of 6.8 degrees occurs at 8:00
1/18 The waxing gibbous Moon is 1.1 degrees north of the bright open cluster M45 (the Pleiades) in Taurus at 7:00
1/19 The Moon is at perigee, subtending 32'37" from a distance of 366,430 kilometers, at 8:33
1/20 Mars is 1.1 degrees south of the Moon - an occultation is visible from northern Russia, the Arctic, and the far northwestern portion of North America - at 0:00
1/22 Mercury is at greatest eastern elongation (19 degrees) at 5:00; Full Moon (known as the Ice Moon, the Moon After Yule, the Old Moon, and the Wolf Moon) occurs at 13:35; the Moon is 0.3 degree north of the bright open cluster M44 (the Beehive Cluster or Prasepe) in Cancer at 23:00
1/23 A minimum lunar libration of 5.5 degrees occurs at 0:00
1/24 The Moon is 0.7 degree south of the first magnitude star Regulus (Alpha Leonis) - an occultation is visible from southern Indonesia, Australasia, and portions of Antarctica - at 15:00
1/25 Saturn is 3 degrees north of the Moon at 6:00
1/26 Comet 8P/Tuttle is at perihelion (1.027 astronomical units) at 5:00
1/27 Mercury is at perihelion today
1/28 Mercury is stationary at 7:00
1/29 Asteroid 1 Ceres (magnitude 8.3) passes 4' south of 38 Arietis today
1/30 Last Quarter Moon occurs at 5:03; Mars is stationary at 21:00
1/31 The Moon is at apogee, subtending 29'32" from a distance of 404,533 kilometers, at 4:25

The Quadrantid meteor shower, whose radiant lies at the junction of the constellations of Boötes, Hercules, and Draco in what was once called Quadrans Muralis, occurs on the morning of January 4. This shower can, on occasion, reach zenithal hourly rates of more than 100 meteors per hour. A waning crescent Moon won’t adversely affect viewing the Quadrantids this year. The near-Earth asteroid 2003 EH1 is thought to be the source of the Quadrantids.

A lunar occultation of some of the Pleiads (i.e., the stars of the Pleiades), including 18 Tauri (5.7 magnitude), takes place for observers in our region during the early morning of January 18. The Moon is 22.3 days old and is located in Virgo on January 1 at 0:00 UT. It’s at its greatest declination north of +28 degrees on January 19 and its greatest declination south of -28 degrees on January 6. Times and dates for the lunar crater light rays predicted to occur this month are available at http://www.lunar-occultations.com/rlo/rays/rays.htm

Data (magnitude, apparent size, illumination, and distance from the Earth in astronomical units) for the planets and Pluto on January 1: Mercury (-0.9, 4.9", 97%, Sagittarius, 1.4 a.u.), Venus (-4.1, 14.5", 76%, Scorpius, 1.2 a.u.), Mars (-1.5, 15.4", 99%, Taurus, 0.61 a.u.), Jupiter (-1.8, 31.7", 100%, Sagittarius, 6.2 a.u.), Saturn (0.6, 19.1", 100%, Leo, 8.7 a.u.), Uranus (5.9, 3.4", 100%, Aquarius, 20.7 a.u.), Neptune (8.0, 2.2", 100%, Capricornus, 30.9 a.u.), and Pluto (14.0, 0.1", 100% illuminated, Sagittarius, 32.3 a.u.).

Mars is in the eastern and Uranus in the southwestern sky during the evening. At midnight, Mars is in the southwest and Saturn is in the southeast. Venus is in the southeast, Jupiter is also in the southeast, and Saturn is in the west in the morning.

Mercury, the messenger of the gods, can be seen during evening twilight. On January 14, the Messenger space probe reaches the planet. Mercury is at its best on January 21, when it sets an hour and a half after the Sun. Mercury (magnitude -0.6) passes 0.3 degree north of a nearly impossible to see Neptune (magnitude 8.0) on the evening of January 22.

Venus is in the morning sky. It rises more than an hour before astronomical twilight on January 1 and around 5:00 a.m. EST by mid-month. During January, the two brightest planets, Venus and Jupiter, grow ever closer as they approach a noteworthy conjunction on February 1. They are 30 degrees apart on January 1, 11 degrees apart on January 21, and only 1.2 degrees apart on January 31. Venus is some two degrees away from M8 (the Lagoon Nebula) on January 24 and is about one degree distant from M20 (the Trifid Nebula) on January 25.

Mars shines brighter than Sirius and subtends a bit more than 15" in early January. It transits the meridian at approximately 10:00 p.m. EST and sets around 6:00 a.m. EST on January 15. The Moon and Mars form a close pair on the night of January 19. Mars is in retrograde (i.e., undergoing westward motion) through Taurus until January 30, when it is 2.5 degrees away from Elnath or Beta Tauri (1.6 magnitude). Afterwards, eastward (prograde or direct motion) resumes. By the end of January, Mars is a 95% illuminated disk that has dimmed to magnitude -0.6 and decreased in size to just over 12". Syrtis Major, the darkest Martian surface feature, is at the center of the disk at 4:00 a.m. EST on January 1. Sinus Meridiani is at the center at 11:00 p.m. EST on January 25. See the Mars Profiler at http://www.skyandtelescope.com/observing/objects/javascript/mars for a hemispherical map of Martian surface features and http://www.skyandtelescope.com/observing/objects/javascript/mars_moons/index.html for the positions of the faint Martian moons Phobos and Deimos.

Jupiter is visible low in the southeast an hour before the Sun rises in mid-January. It is less than one degree north of the bright globular cluster M22 on January 25.

Saturn is in Leo for the entire year. In early January, it rises around 9:00 p.m. EST and at approximately 8:00 p.m. EST by the middle of the month. It transits around 3:00 a.m. EST in mid-January. Saturn heads towards Regulus during January, ending the month 7 degrees away from the first magnitude star. Saturn’s ring tilt angle is 6.7 degrees on New Year’s Day. This month Titan shines at approximately magnitude 8.5, Rhea at 10.0, and Dione and Tethys at 10.5. Iapetus, whose brightness ranges from tenth magnitude when it is to the west of Saturn to twelfth magnitude when it is to the east of the planet, is due east of Saturn by the listed separations at 0:00 UT on the following dates: January 7 (17"), January 13 (31"), January 19 (39"), January 23 (40"), January 27 (36"), and January 31 (29"). It is less than two planetary diameters north of Saturn on the night of January 1. For additional information on the satellites of Saturn, http://www.skyandtelescope.com/observing/objects/javascript/saturn_moons

Uranus can still be seen immediately after dark in early January. It’s situated low in the southwest about one degree northeast of the fourth magnitude star Lambda Aquarii.

Neptune is lost in the glow of sunset during January.

Pluto is also not observable this month.

This month periodic comet 8P/Tuttle heads southward towards the Sun through the constellations of Pisces, Aries, Cetus, and Fornax. It passed within a degree of the spiral galaxy M33 in Triangulum on December 30, is 6 degrees to the northwest of Hamal (Alpha Arietis) on January 1, and lies just to the east of the spiral galaxy M74 in Pisces on January 4. The best time to view the comet, which may reach a peak magnitude of 5.5, is before January 14, when an increasingly bright Moon becomes a problem. It is well-positioned from sunset to 10:00 p.m. Near the end of the month, Comet 8P/Tuttle enters Eridanus and is lost to northern hemisphere observers. It won't be seen again until 2021.

Asteroid 1 Ceres (magnitude 8.3), which is now also classified as a dwarf planet, passes northeastward through Cetus and into Aries during January. On January 29, the 975 by 909 kilometer asteroid passes 4' south of the fifth magnitude star 38 Arietis.

One hundred and five binary and multiple stars for January: Omega Aurigae, 5 Aurigae, Struve 644, 14 Aurigae, Struve 698, Struve 718, 26 Aurigae, Struve 764, Struve 796, Struve 811, Theta Aurigae (Auriga); Struve 485, 1 Camelopardalis, Struve 587, Beta Camelopardalis, 11 & 12 Camelopardalis, Struve 638, Struve 677, 29 Camelopardalis, Struve 780 (Camelopardalis); h3628, Struve 560, Struve 570, Struve 571, Struve 576, 55 Eridani, Struve 596, Struve 631, Struve 636, 66 Eridani, Struve 649 (Eridanus); Kappa Leporis, South 473, South 476, h3750, h3752, h3759, Beta Leporis, Alpha Leporis, h3780, Lallande 1, h3788, Gamma Leporis (Lepus); Struve 627, Struve 630, Struve 652, Phi Orionis, Otto Struve 517, Beta Orionis (Rigel), Struve 664, Tau Orionis, Burnham 189, h697, Struve 701, Eta Orionis, h2268, 31 Orionis, 33 Orionis, Delta Orionis (Mintaka), Struve 734, Struve 747, Lambda Orionis, Theta-1 Orionis (the Trapezium), Theta-2 Orionis, Iota Orionis, Struve 750, Struve 754, Sigma Orionis, Zeta Orionis (Alnitak), Struve 790, 52 Orionis, Struve 816, 59 Orionis, 60 Orionis (Orion); Struve 476, Espin 878, Struve 521, Struve 533, 56 Persei, Struve 552, 57 Persei (Perseus); Struve 479, Otto Struve 70, Struve 495, Otto Struve 72, Struve 510, 47 Tauri, Struve 517, Struve 523, Phi Tauri, Burnham 87, Xi Tauri, 62 Tauri, Kappa & 67 Tauri, Struve 548, Otto Struve 84, Struve 562, 88 Tauri, Struve 572, Tau Tauri, Struve 598, Struve 623, Struve 645, Struve 670, Struve 674, Struve 680, 111 Tauri, 114 Tauri, 118 Tauri, Struve 730, Struve 742, 133 Tauri (Taurus)

Challenge binary star for January: 14 Orionis

Notable variable star for January: U Orionis

Notable carbon star for January: R Leporis

Seventy deep-sky objects for January: B26-28, B29, M36, M37, M38, NGC 1664, NGC 1778, NGC 1857, NGC 1893, NGC 1907, NGC 1931 (Auriga); IC 361, Kemble 1 (Kemble’s Cascade asterism), NGC 1501, NGC 1502, NGC 1530, NGC 1569 (Camelopardalis); NGC 1507, NGC 1518, NGC 1531, NGC 1532, NGC 1535, NGC 1537, NGC 1600, NGC 1637, NGC 1659, NGC 1700 (Eridanus); IC 418, M79, NGC 1832, NGC 1888, NGC 1964 (Lepus); B33, Cr65, Cr69, Cr70, IC 434, M42, M43, M78, NGC 1662, NGC 1973-75-77, NGC 1981, NGC 1999, NGC 2022, NGC 2023, NGC 2024, NGC 2112 (Orion); Be11, NGC 1491, NGC 1496, NGC 1499, NGC 1513, NGC 1528, NGC 1545, NGC 1548, NGC 1579, NGC 1582, NGC 1605, NGC 1624 (Perseus); DoDz3, DoDz4, M1, Mel 25, NGC 1514, NGC 1587, NGC 1647, NGC 1746, NGC 1807, NGC 1817 (Taurus)

Top ten binocular deep-sky objects for January: Kemble 1, M36, M37, M38, M42, NGC 1528, NGC 1647, NGC 1746, NGC 1981

Top ten deep-sky objects for January: M42, M43, M78, M79, NGC 1499, NGC 1501, NGC 1502, NGC 1514, NGC 1931, NGC 2024

Challenge deep-sky object for January: IC 2118 (Eridanus)

The objects listed above are located between 4:00 and 6:00 hours of right ascension.

--------------------
Chance favors the prepared mind.
De gustibus non est disputandum.