January Celestial Calendar by Dave Mitsky
All times are UT (subtract five hours, and one calendar day when appropriate, for EST)
1/1 Mercury is at greatest western elongation (22.7 degrees) at 20:00; the Moon is at perigee, the closest one of 2018, subtending 33' 31" from a distance of 356,565 kilometers (221,559 miles), at 21:49
1/2 Full Moon (known as the Ice Moon, the Moon after Yule, the Old Moon, and the Wolf Moon), the largest Full Moon of 2018, occurs in Gemini at 2:24; asteroid 8 Flora (magnitude +8.2) is at opposition in Gemini at 18:00; Uranus is stationary in right ascension at 21:00
1/3 The Earth is at perihelion (147,097,223 kilometers or 91,401,983 miles distant from the Sun) at 5:35; the Moon is 2.3 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 19:50; the peak of the Quadrantid meteor shower (40 to 120 or more per hour) occurs at 20:00
1/4 The latest sunrise of 2018 at latitude 40 degrees north occurs today; the Moon is at the ascending node at 7:48
1/5 The Moon is 0.9 degree north of the first-magnitude star Regulus (Alpha Leonis), with an occultation occurring in northern Canada and Alaska, at 7:24
1/7 The latest onset of morning twilight of 2018 at latitude 40 degrees north occurs today; Mars is 0.25 degree south of Jupiter today
1/8 Last Quarter Moon occurs at 22:25
1/9 Venus is in superior conjunction at 7:00; Pluto is in conjunction with the Sun at 10:00
1/10 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to be at a midpoint at 17:13
1/11 The Moon is 4.3 degrees north of Jupiter at 5:59; the Moon is 4.6 degrees north of Mars at 10:03
1/12 The Moon is 0.4 degree south of the asteroid 4 Vesta at 4:00
1/13 Mercury (magnitude -0.3) is 0.6 degree north of Saturn (magnitude +0.5) at 8:00
1/15 The Moon is at apogee, subtending 29' 24" from a distance of 406,464 kilometers (252,565 miles), at 2:10; the Moon is 2.6 degrees north of Saturn at 2:13; the Moon is 3.4 degrees north of Mercury at 7:24
1/17 New Moon (lunation 1176) occurs at 2:17
1/18 The Moon is at the descending node at 14:28
1/20 The Moon is 1.6 degrees south of Neptune at 20:00
1/23 Venus is at aphelion at 17:00
1/24 The Moon is 5.0 degrees north of Uranus at 1:00; 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 approximately 4:42; sunrise takes place on the isolated lunar mountain Mons Pico at 9:53; First Quarter Moon occurs at 22:20
1/25 Sunrise takes place on the isolated lunar mountain Mons Piton at 1:12; Mercury is at aphelion at 11:00
1/27 The Moon is 0.7 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation taking place in Canada, Alaska, and central and southern Asia, at 10:09
1/30 The Moon is at perigee, subtending 33' 17" from a distance of 358,994 kilometers (223,068 miles), at 9:57
1/31 The Moon is 2.3 degrees south of M44 at 7:19; asteroid 1 Ceres (magnitude +6.8) is at opposition in Cancer at 13:00; Full Moon occurs in Cancer at 13:27; a total lunar eclipse is underway, with the eclipsed Moon reaching greatest eclipse at 13:29; the Moon is at the ascending node at 18:46
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. Galileo Galilei discovered Ganymede on January 13, 1610. Nicolas-Louis de Lacaille discovered NGC 3372 (the Eta Carinae Nebula) on January 25, 1752. Charles Messier discovered the globular cluster M56 on January 23, 1779. Charles Messier discovered the globular cluster M80 on January 4, 1781. William Herschel discovered the spiral galaxy NGC 1084 on January 10, 1785. Pierre François André Méchain discovered Comet 2P/Encke on January 17, 1786. 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. Philibert Jacques Melotte discovered the Jovian satellite Pasiphae on January 27, 1908. 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. Bright moonlight from the 96%-illuminated, waning gibbous Moon will compromise the peak of this year’s Quadrantids. The Quadrantid shower can sometimes reach zenithal hourly rates of more than 100 meteors per hour for a relatively short period of time. 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 51 of the January 2018 issue of Sky & Telescope or browse http://earthsky.org/?p=155137 and http://meteorshowers...uadrantids.html 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.c...=42301117054103
The Moon is 13.7 days old, is illuminated 98.1%, subtends 33.8 arc minutes, and is located in Taurus on January 1st at 0:00 UT. The Moon is at perigee on January 1st and January 30th and at apogee on January 15th. New Moon occurs on January 17th. So-called supermoons take place on January 2nd and January 31st. A supermoon is more actually described as a perigee syzygy of the Earth-Moon-Sun system or more simply as a perigean Full Moon. The Full Moon on January 31st is also a blue moon by one definition, that being the second Full Moon occurring in a month. A total lunar eclipse takes place in western North America, the Pacific Ocean, Asia, and Australia on January 31st. The first penumbral contact occurs at 10:51 UT and the fourth at 16:08 UT. The instant of greatest eclipse takes place at 13:29 UT. Totality lasts for one hour and sixteen minutes. The eclipse is the 49th of the 74 eclipses comprising Saros 124. For more on this event, browse https://www.timeandd...2018-january-31 and http://eclipsewise.c...an31Tprime.html or see page 50 of the January 2018 issue of Sky & Telescope and page 39 of the January 2018 issue of Astronomy. The waning gibbous Moon occults Regulus from portions of northern Canada and Alaska on the night of January 4th. The 80%-illuminated gibbous Moon occults Aldebaran from far northwestern North America on the morning of January 27th. Click on http://www.lunar-occ...ota/iotandx.htm for information on these events. Visit https://saberdoesthe...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 19th.
Data (magnitude, apparent size, illumination, and distance from the Earth in astronomical units) for the planets and Pluto on January 1: Mercury (-0.3, 6.7", 62%, 1.00 a.u., Ophiuchus), Venus (-4.0, 9.8", 100%, 1.71 a.u., Sagittarius), Mars (+1.5, 4.8", 93%, 1.96 a.u., Libra), Jupiter (-1.8, 33.1", 99%, 5.96 a.u., Libra), Saturn (+0.5, 15.1", 100%, 11.03 a.u., Sagittarius), Uranus (+5.8, 3.5", 100%, 19.90 a.u. on January 16th, Pisces), Neptune (+7.9, 2.2", 100%, 30.61 a.u. on January 16th, Aquarius), Pluto (+14.3, 0.1", 100%, 34.45 a.u. on January 16th, Sagittarius).
During the evening, Uranus lies in the south and Neptune in the southwest. At midnight, Uranus is in the west. Mercury, Mars, and Saturn can be seen in the southeast and Jupiter in the south in the morning.
In early January, the Sun, Venus, Saturn, and Pluto are all located in Sagittarius and Mars and Jupiter are located in Libra. On January 11th, the waning crescent Moon, Mars, and Jupiter form a compact triangle in the pre-dawn sky. Mercury, Saturn, and a very thin waning crescent Moon form a triangle very low in the southeastern morning sky on January 15th.
Mercury grows brighter (magnitude -0.3 to magnitude -0.5) as it shrinks in apparent size (6.7 arc seconds to 4.9 arc seconds) but waxes in phase (62% illumination to 95% illumination) during the course of the month. Mercury is at greatest western elongation on January 1st. On January 13th, Mercury and Saturn are only 0.6 degree apart.
Venus reaches superior conjunction on January 9th and consequently is not visible this month.
Earth is 0.9833 a.u. distant from the Sun at perihelion on January 3rd. On that date, it’s 3% (5.0 million kilometers or 3.1 million miles) closer to the Sun than at aphelion on July 6th and about 2.7% closer to the Sun than on average.
Mars grows a bit larger and brighter and exhibits a gibbous phase this month. The Red Planet (magnitude +1.5) lies 2.6 degrees west of Jupiter (magnitude -1.8) on the first day of the year. Mars passes 0.6 degree north of the third-magnitude double star Zubenelgenubi (Alpha Librae) on January 2nd. Mars and Jupiter are separated by just 16 arc minutes, their closest conjunction since 2004, on January 7th. Mars is 4.6 degrees south of the waning crescent Moon on January 11th. It enters Scorpius on January 31st. On that date, Mars is positioned nine degrees northwest of Antares (magnitude +1.1), the rival of Mars.
During January, Jupiter’s disk increases in size from 33.1 arc seconds to 35.8 arc seconds as it brightens from magnitude -1.8 to magnitude -2.0. 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 2018 issue of Sky & Telescope. Click on http://www.skyandtel...watching-tools/ or consult page 50 of the January 2018 issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot.
Saturn climbs higher into the morning sky as the month progresses. It attains an altitude of about ten degrees an hour before sunrise by January’s end. At that time, the Ringed Planet rises over two hours before the Sun.
Throughout January, Uranus can be found approximately 3 degrees north of the fifth-magnitude star Mu Piscium.
Neptune is located 0.5 degree southeast of the fourth-magnitude star Lambda Aquarii on January 1st. By the end of the month, Neptune lies 1.1 degrees due east of that star.
See http://www.curtrenz.com/uranep.html for additional information on the two outer planets.
The dwarf planet Pluto is in conjunction with the Sun on January 7th.
Asteroid 20 Massalia drops slightly in brightness to ninth magnitude as it takes a westward course through eastern Taurus this month. It passes about 0.5 degree to the west of the fifth-magnitude star 114 Tauri on January 1st and 0.2 degree to the south of the fifth-magnitude star 109 Tauri on January 10th and January 11th. Massalia is positioned approximately 0.5 degree south of the sixth-magnitude star 108 Tauri on January 18th and is even closer on January 31st as it proceeds on an eastward prograde loop. The dwarf planet/asteroid 1 Ceres (magnitude +6.8) is at opposition in Cancer on January 31st. See http://asteroidoccul.../2018_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 C/2016 R2 (PanSTARRS) may shine at tenth magnitude as it glides northwestward through Taurus. It passes about two degrees southwest of Melotte 25 (the Hyades) on January 1st. By January 31st, the comet lies a bit more than two degrees to the southeast of M45 (the Pleiades). 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. A discussion on upcoming comets for this year can be heard at https://soundcloud.c...comets-for-2018
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 1st, 4th, 7th, 10th, 13th, 15th, 18th, 21st, 24th, 27th, and 30th. Consult page 50 of the January 2018 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...ars2/algol3.htm
Data on current supernovae can be found at http://www.rochester...y.org/snimages/
Information on observing some of the more prominent Messier galaxies is available 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.