January Celestial Calendar by Dave Mitsky
All times are UT (subtract five hours, and one calendar day when appropriate, for EST)
1/1 Mars is 0.02 degree south of Neptune at 7:00
1/2 Venus is 1.9 degrees south of the Moon at 9:00; the Moon is at the descending node at 18:14
1/3 Neptune is 0.4 degree south of the Moon, with an occultation visible from the west coast of North America, at 4:00; Mars is 0.2 degree south of the Moon, with an occultation taking place that is not visible from North America, at 6:47; the peak of the Quadrantid meteor shower (40 to 120 or more per hour) occurs at 14:00
1/4 The latest sunrise of 2017 at latitude 40 degrees north occurs today; the Earth is at perihelion (147,100,998 kilometers or 91,404,322 miles distant from the Sun) at 14:00
1/5 The Lunar X (the Purbach or Werner Cross), an X-shaped illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to begin at 6:54; First Quarter Moon occurs at 19:47
1/6 Uranus is 3.0 degrees north of the Moon at 2:00
1/7 The latest onset of morning twilight of 2017 at latitude 40 degrees north occurs today; Pluto is in conjunction with the Sun at 7:00
1/8 Mercury is stationary in right ascension at 10:00
1/9 Mercury is 6.7 degrees north of Saturn at 9:00; the Moon is 0.4 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation taking place at various locations in Asia, at 14:07
1/10 The Moon is at perigee, subtending 32' 54" from a distance of 363,238 kilometers (225,706 miles), at 6:01
1/12 Jupiter is at western quadrature today; Full Moon (known as the Ice Moon, the Moon after Yule, the Old Moon, and the Wolf Moon) occurs in Gemini at 11:34; Venus is at greatest eastern elongation (47.1 degrees) at 13:00
1/13 Venus is 0.4 degree north of Neptune at 2:00; the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer is 3.9° north of the Moon at 13:59
1/14 Venus is at dichotomy (50% illumination) today
1/15 The Moon is 0.8 degree south of the first-magnitude star Regulus (Alpha Leonis) at 4:00; the Moon is at the ascending node at 10:44
1/18 Asteroid 4 Vesta (magnitude +6.2) is at opposition at 1:00
1/19 Jupiter is 3.0 degrees south of the Moon at 5:00; Mercury is at greatest western elongation (24.1 degrees) at 10:00; Last Quarter Moon occurs at 22:13
1/22 The Moon is at apogee, subtending 29'31" from a distance of 404,914 kilometers (251,602 miles), at 00:14
1/24 Saturn is 4.0 degrees south of the Moon at 10:00
1/26 Mercury is 4.0 degrees south of the Moon at 1:00
1/28 New Moon (lunation 1164) occurs at 00:07
1/29 The Moon is at the descending node at 22:21
1/30 Neptune is 0.2 degree south of the Moon, with an occultation taking place that is not visible from North America, at 11:00
1/31 Jupiter is 3.5 degrees north of the first-magnitude star Spica (Alpha Virginis) at 13:00; Venus is 4.0 degrees north of the Moon at 15:00
Johannes Hevelius (1611-1687), Ernst Abbe (1840-1905), George Van Biesbroeck (1880-1974), Luboš Kohoutek (1935), and Stephen Hawking (1942) were born this month.
Galileo Galilei discovered Io, Europa, and Callisto on January 7, 1610. He discovered Ganymede on January 13, 1610. William Herschel discovered Titania and Oberon, two satellites of Uranus, on January 11, 1787. Giuseppe Piazzi discovered the first asteroid, 1 Ceres, on January 1, 1801. Louis Daguerre took the first photograph of the Moon on January 2, 1839. Alvan Clark discovered the white dwarf star Sirius B (the Pup) on January 31, 1862. The 36-inch Clark refractor at the Lick Observatory saw first light on January 3, 1888. Charles Perrine discovered the Jovian satellite Elara on January 2, 1905. Clyde Tombaugh photographed Pluto on January 23, 1930. Mike Brown, Chad Trujillo, and David Rabinowitz discovered Eris on January 5, 2005.
The Quadrantid meteor shower peaks on January 3rd. The Moon will not interfere with watching the peak of the shower this year. The Quadrantid shower can sometimes reach zenithal hourly rates of more than 100 meteors per hour. The radiant of the Quadrantids lies at the junction of the constellations of Boötes, Hercules, and Draco, in what was once called Quadrans Muralis. The near-Earth asteroid 2003 EH1, which may be an extinct comet, is believed to be the source of these meteors. See page 50 of the January issue of Sky & Telescope or browse http://meteorshowers...uadrantids.html and http://earthsky.org/?p=4287 for more on the Quadrantids.
Information on Iridium flares and passes of the ISS, the Tiangong-1, the Tiangong-2, the X-37B, the HST, and other satellites can be found at http://www.heavens-above.com/ and https://www.calsky.com/cs.cgi/Satellites?obs=42301117054103
The Moon is 2.7-days old, is illuminated 7.2%, subtends 30.6 arc minutes, and is located in Capricornus on January 1st at 0:00 UT. The Moon is at perigee on January 10th and at apogee on January 22nd. New Moon occurs on January 28th. The Moon occults Neptune and Mars from certain parts of the world this month. The waxing gibbous Moon occults the fourth-magnitude star Gamma Tauri in the early morning of January 9th. Consult http://www.lunar-occ...r/0109zc635.htm for further information. The Moon will also occult Theta 1 and Theta 2 Tauri from parts of Canada, Alaska, and eastern Asia and Aldebaran from parts of Asia on that date. Click on http://www.lunar-occ...ota/iotandx.htm for information on these events. The Last Quarter Moon, Jupiter, and Spica form a close triangle at dawn on January 19th. Visit http://saberdoesthes...does-the-stars/ for tips on spotting extreme crescent Moons and http://www.curtrenz.com/moon06.html for Full Moon data. Times and dates for the lunar light rays predicted to occur this month are available at http://www.lunar-occ...o/rays/rays.htm
The Sun is located in Sagittarius on January 1st. It enters Capricornus on January 25th.
Data (magnitude, apparent size, illumination, and distance from the Earth in astronomical units) for the planets and Pluto on January 1: Mercury (+3.3, 9.8", 5%, 0.68 a.u., Sagittarius), Venus (-4.4, 21.7", 57%, 0.77 a.u., Aquarius), Mars (+0.9, 5.7", 90%, 1.64 a.u., Aquarius), Jupiter (-1.9, 35.5", 99%, 5.55 a.u., Virgo), Saturn (+0.5, 15.2", 100%, 10.97 a.u., Ophiuchus), Uranus (+5.8, 3.5", 100%, 20.01 a.u. on December 16th, Pisces), Neptune (+7.9, 2.2", 100%, 30.65 a.u. on December 16th, Aquarius), Pluto (+14.3, 0.1", 100%, 33.22 a.u. on December 16th, Sagittarius).
During the evening, Venus, Mars, and Neptune lie in the southwest and Uranus in the south. At midnight, Uranus is in the west. Mercury and Saturn can be seen in the southeast and Jupiter in the south in the morning.
Jupiter and Saturn will not be occulted by the Moon this year.
Mercury grows brighter (magnitude +3.3 to magnitude -0.2) as it shrinks in apparent size (9.8 arc seconds to 5.6 arc seconds) but waxes in phase (5% illumination to 80% illumination) during the course of the month. The speediest planet should be visible to the lower left of Saturn after January 5th. The gap between the two planets shrinks to 7 degrees by January 9th. Mercury is stationary in right ascension on January 8th and is at greatest eastern elongation on January 19th.
Venus increases in brightness from magnitude -4.4 to magnitude -4.7 this month. It's at greatest eastern elongation (47.1 degrees) on January 12th and reaches dichotomy (50% illumination) on January 14th. Venus passes 0.4 degree north of Neptune on January 13th. The brightest planet lies two degrees south of the Moon on January 2nd and four degrees north of the Moon on January 31st. The gap between Venus and Mars decreases to 5.5 degrees by January 31st.
Earth is 0.9833 a.u. distant from the Sun at perihelion on January 4th. On that date, it’s about 3% (5.0 million kilometers or 3.1 million miles) closer to the Sun than at aphelion in July.
Mars grows smaller and dimmer in January. The Red Planet exhibits a gibbous phase this month. Mars (5.7 arc minutes) and Neptune (2.2 arc minutes) experience an extremely close conjunction on the night of December 31st-January 1st. Mars departs Aquarius and enters Pisces on the night of January 18th-January 19th. Mars (magnitude +1.1), Venus (magnitude -4.7), and the young crescent Moon form a compact triangle on the evening of January 31st.
During January, Jupiter’s disk increases in size by 3.4 arc seconds to 38.9 arc seconds. It brightens from magnitude -19.2 to magnitude -2.1. The waning gibbous Moon passes 3.0 degrees north of Jupiter on the evening of January 19th. Shadow transits by Io take place on January 6th starting at 5:24 a.m. EST (10:24 UT) and January 15th starting at 1:45 a.m. EST (6:45 UT). A shadow transit by Europa occurs on January 18th beginning at 1:12 a.m. EST (6:12 UT). On the morning of January 22nd, Callisto is south of Jupiter. Data on Galilean satellite events is available online at http://www.shallowsky.com/jupiter/ and http://www.skyandtel...watching-tools/ and on page 51 of the January issue of Sky & Telescope. Click on http://www.skyandtel...watching-tools/ or consult page 50 of the January issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot.
Saturn rises 90 minutes before sunrise on January 1st and three hours before sunrise on January 31st. At the end of the month, the planet’s disk subtends almost 16 arc seconds and its rings span 35 arc seconds. (Saturn’s rings are 2.27 times larger in extent than the planet’s equatorial diameter.) Saturn lies four degrees south of the Moon on January 24th. For information on the satellites of Saturn, browse http://www.skyandtel...watching-tools/
Uranus can be found 0.6 degree east of the fifth-magnitude star Zeta Piscium on January 1st. By month’s end, it’s situated 1.0 degree east of that star. Uranus sets around local midnight this month.
Neptune is located 0.5 degree west-southwest of Mars on January 1st and 0.4 degree south of Venus on January 12th. The eighth planet lies 2.1 degrees southwest of the fourth-magnitude star Lambda Aquarii on January 1st. By January 31st, Neptune is within 1.3 degrees of that star.
See http://www.curtrenz.com/uranep.html for additional information on the two outer planets.
Finder charts for Uranus and Neptune appear on page 50 of the October 2016 issue of Sky & Telescope. A finder chart for Uranus also appears on page 49 of the December 2016 issue of Sky & Telescope. Online finder charts for the two planets can be found at http://www.nakedeyep....com/uranus.htm and http://www.nakedeyep...com/neptune.htm and also at http://www.skyandtel...6_Finders.pdf
The dwarf planet Pluto is in conjunction with the Sun on January 7th.
Asteroid 4 Vesta (magnitude +6.2) reaches opposition on the night of January 17th-January 18th. The third-largest main belt asteroid starts the month in Cancer to the east of the sixth-magnitude star Mu Cancri and ends it in Gemini 0.7 degree east-northeast of the fourth-magnitude star Kappa Geminorum. Asteroid 13 Egeria (magnitude +10.1) reaches opposition on January 8th and 21 Lutetia (magnitude +10.9) on January 11th. See http://asteroidoccul.../2017_01_si.htm for information on asteroid occultation events taking place this month. Consult http://www.curtrenz.com/asteroids.html to learn more about a number of asteroids.
Comet 45/P Honda-Mkros-Pajdušáková may brighten to seventh magnitude as it heads northeastward through Capricornus in early January. It will be situated at an altitude of just 10 degrees in the southwest at 6:00 p.m. local time and will set not long afterwards. The periodic comet will reappear in the morning sky by the end of the month. Comet C/2016 U1 NEOWISE may brighten to sixth magnitude in mid-January. It will pass near the globular M14 in Ophiuchus on January 3rd, the third-magnitude star Nu Ophiuchi on January 7th, M16 (the Eagle Nebula) in Serpens Cauda on January 10th, M17 (the Swan Nebula) in Serpens Cauda, and the open cluster M25 in Sagittarius on January 13th. Visit http://cometchasing.skyhound.com/ and http://www.aerith.ne...t/future-n.html for information on comets visible this month and in the near future.
Various events taking place within our solar system are discussed at http://www.bluewater...ed-4/index.html
Omicron2 (40) Eridani is a fourth-magnitude triple star system consisting of three dwarf stars: a type K1V yellow-orange dwarf (A) known as Keid, a type DA4 white dwarf (B), and a type M4.5e red dwarf ©. Omicron is located about 16 light years from the Earth at 4h15m16.32s, -7°39′10.34″. Ninth-magnitude Omicron B is the most easily visible white dwarf star and can be seen with an aperture of six inches.
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from 2.1 to 3.4, on January 2nd, 5th, 8th, 11th, 13th, 16th, 19th, 22nd, 25th, 28th, and 31st. Consult page 50 of the January issue of Sky & Telescope for the times of the minima. The Demon Star is at minimum brightness for approximately two hours centered at 9:19 p.m. EST on January 10th and at 11:04 p.m. EST on January 30th. For more on Algol, see http://stars.astro.i.../sow/Algol.html and http://www.solstatio...rs2/algol3.htm
RW Tauri, another well-known eclipsing variable star, is visible this month. This eight-magnitude star is located five degrees northeast of M45 (the Pleiades) and is the deepest eclipsing binary (over three magnitudes) known. Eclipse dates and times appear on page 49 of the January 2017 issue of Sky & Telescope.
Information pertaining to observing some of the more prominent Messier galaxies can be found at http://www.cloudynig...ur-astronomers/
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)
Notable carbon star for January: R Leporis (Hind’s Crimson Star)
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: Cr65, Kemble 1, M36, M37, M38, M42, NGC 1528, NGC 1647, NGC 1746, NGC 1981
Top ten deep-sky objects for January: M1, M36, M37, M38, M42, M43, M78, M79, NGC 1501, 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.