From our Friend Dave Mtsky -January Sky Events
All times are UT (subtract five hours, and one calendar day when appropriate, for EST)
1/1 The Moon is 1.3 degrees north of Venus at 22:00
1/2 Mercury is at the descending node through the ecliptic plane at 0:00; Mars crosses north of the celestial equator at 1:00; Saturn is in conjunction with the Sun at 6:00
1/3 The Moon is 8.4 degrees north-northeast of first-magnitude star Antares (Alpha Scorpii) at 5:00; the Earth is at perihelion (147,099,761 kilometers or 91,403,554 miles distant from the Sun) at 5:20; the Moon is 3.1 degrees north-northeast of Jupiter at 10:00
1/4 The latest sunrise of 2019 at latitude 40 degrees north occurs today; the peak of the Quadrantid meteor shower (40 to 120 or more per hour) is predicted to occur at 2:30; the Moon is 2.8 degrees north of Mercury at 19:00
1/5 The Moon is 0.9 degree north of Saturn at 19:00; Venus is at dichotomy (50% illuminated) at 19:00; a partial solar eclipse visible from China, Korea, Japan, Russia, the northern Pacific Ocean, and the Aleutian Islands begins at 23:34
1/6 New Moon (lunation 1188) occurs at 1:28; the instant of greatest eclipse for the ongoing partial solar eclipse takes place at 01:41; the partial solar eclipse ends at 3:48; Venus is at greatest western elongation (46.9 degrees) at 5:00; Uranus is stationary in longitude at 18:00
1/7 Uranus is stationary in right ascension, with direct motion to resume, at 0:00; the Moon is at descending node (longitude 296.7 degrees) at 0:08; the Moon displays minimum libration for the year (1.2 degrees) at 15:00
1/8 The latest onset of morning twilight of 2019 at latitude 40 degrees north occurs today
1/9 The Moon is at apogee, subtending 29′ 25″ from a distance of 406,117 kilometers (252,850 miles), at 4:00
1/10 Mercury is at its southernmost declination (-24.1 degrees) at 18:00; the Moon is 3.0 degrees south of Neptune at 22:00
1/11 Pluto is in conjunction with the Sun at 12:00
1/12 Mercury is at aphelion (0.4667 a.u. from the Sun) at 8:00
1/13 The Moon is 5.0 degrees south-southeast of Mars at 1:00; Mercury (magnitude -0.6) is 1.7 degrees south of Saturn (magnitude +0.5) at 12:00; 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 be fully formed at approximately 12:35
1/14 First Quarter Moon occurs at 6:46; the Moon is 4.8 degrees south-southeast of Uranus at 17:00
1/15 Mars is at the ascending node through the ecliptic plane at 5:00
1/16 Venus (magnitude -4.4) is 7.8 degrees north of the first-magnitude star Antares at 23:00
1/17 The Moon is 8.5 degrees south-southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 3:00; the middle of the eclipse season (the Sun is at same longitude as the descending node of the Moon, 296.7 degrees) occurs at 8:00; Venus is at its northernmost latitude from the ecliptic plane (3.4 degrees) at 8:00; the Moon is 1.6 degrees north of the first magnitude star Aldebaran (Alpha Scorpii) at 19:00
1/18 Mercury (magnitude -0.8) is 1.5 degrees south of Pluto (magnitude +14.3) at 20:00
1/19 Uranus is at eastern quadrature (90 degrees from the Sun) at 1:00
1/20 The Sun enters Capricornus (ecliptic longitude 299.7 degrees) at 2:00; the Moon is 7.0 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 19:00; the Moon is at the ascending node (longitude 116.8 degrees) at 22:48
1/21 A partial lunar eclipse begins at 3:34; the instant of greatest eclipse occurs at 5:12; Full Moon (known as the Ice Moon, the Moon after Yule, the Old Moon, and the Wolf Moon) occurs at 5:16; the partial lunar eclipse ends at 6:51; the Moon is 0.6 degree south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 15:32; the Moon is at perigee (just 14.7 hours after Full Moon), subtending 33′ 26″ from a distance of 357,342 kilometers (222,042 miles), at 20:00
1/22 Venus (magnitude -4.3) is 2.4 degrees north of Jupiter (magnitude -1.8) at 16:00
1/23 The Moon is 2.5 degrees north-northeast of the first-magnitude star Regulus (Alpha Leonis) at 4:00
1/26 The Moon is 7.3 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis), at 21:00
1/27 The Moon displays maximum libration for the year (10.1 degrees) at 17:00; Last Quarter Moon occurs at 21:10
1/29 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to be fully formed at 15:54
1/30 Mercury is at superior conjunction with the Sun (latitude -6.9 degrees) at 3:00; the Moon is 8.4 degrees north-northeast of Antares at 11:00
1/31 The Moon is 2.7 degrees north-northeast of Jupiter at 2:00; the Moon is 0.1 degree east-northeast of Venus, with an occultation occurring in western South America and Polynesia, at 18:00
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. Galileo Galilei discovered Ganymede on January 13, 1610. Nicolas-Louis de Lacaille discovered the emission nebula 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 is predicted to peak around 9:00 p.m. EST on January 3rd. Unfortunately, the radiant, which lies at the junction of the constellations of Boötes, Hercules, and Draco, in what was once called Quadrans Muralis, will be below the horizon at that time. However, a waning crescent Moon will not compromise 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 near–Earth asteroid 2003 EH1, which may be an extinct comet, is believed to be the source of these meteors. See pages 48 and 49 of the January 2019 issue of Sky & Telescope or browse http://earthsky.org/?p=155137 and https://amsmeteors.org/2018/12/viewing-the-2019-quadrantid-meteor-shower/ for more on the Quadrantids.
Information on Iridium flares and passes of the ISS, 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 24.5 days old, is illuminated 25.0%, subtends 30.4 arc minutes, and is located in Libra on January 1st at 0:00 UT. The Moon is at apogee (distance 63.67 Earth-radii) on January 9th and is at perigee (distance 56.03 Earth-radii) on January 21st. New Moon occurs on January 6th. A so-called supermoon, the first of three for 2019, occurs on January 21st. A supermoon is more accurately described as a perigee syzygy of the Earth-Moon-Sun system or more simply as a perigean Full Moon. A total lunar eclipse, the 27th of Saros 134, takes place throughout most of North America, South America, the eastern Pacific Ocean, the western Atlantic Ocean, extreme western Europe, and extreme western Africa on January 21st. The Moon is located in Gemini during this event. The first penumbral contact occurs at 2:36 UT and the fourth at 7:48 UT. The partial phase begins at 3:34 UT and ends at 6:51 UT. Totality starts at 7:41 UT and ends at 7:44 UT. The instant of greatest eclipse takes place at 5:12 UT. The bright open cluster M44 lies some seven degrees to the east of the Moon during the eclipse. For more on this event, browse https://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2019Jan21T.pdf and http://www.eclipsewise.com/lunar/LEprime/2001-2100/LE2019Jan21Tprime.html or see pages 18-21 of the January 2019 issue of Sky & Telescope and page 36 of the January 2019 issue of Astronomy. The Moon occults Venus on January 31st from western South America and Polynesia. See http://www.lunar-occultations.com/iota/planets/0131venus.htm for further information. Click on http://www.lunar-occultations.com/iota/iotandx.htm for information on other lunar occultation events. Visit https://saberdoesthestars.wordpress.com/2011/07/05/saber-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 crater light rays predicted to occur this month are available at http://www.lunar-occultations.com/rlo/rays/rays.htm
The Sun is located in Sagittarius on January 1st. It enters Capricornus on January 20th. A partial solar eclipse, the 58th of Saros 102, will be visible from parts of northeastern Asia and the northern Pacific Ocean on January 6th. For more on this eclipse, see https://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/SE2019Jan06P.GIF and http://www.eclipsewise.com/solar/SEprime/2001-2100/SE2019Jan06Pprime.html
Data (magnitude, apparent size, illumination, and distance from the Earth in astronomical units) for the planets and Pluto on January 1st: Mercury (-0.4, 5.2″, 89%, 1.30 a.u., Ophiuchus), Venus (-4.6, 26.3″, 47%, 0.64 a.u., Libra), Mars (+0.5, 7.4″, 87%, 1.26 a.u., Pisces), Jupiter (-1.8, 31.8″, 100%, 6.19 a.u., Ophiuchus), Saturn (+0.5, 15.0″, 100%, 11.04 a.u., Sagittarius), Uranus (+5.8, 3.6″, 100%, 19.78 a.u. on January 16th, Pisces), Neptune (+7.9, 2.2″, 100%, 30.58 a.u. on January 16th, Aquarius), Pluto (+14.3, 0.1″, 100%, 34.70 a.u. on January 16th, Sagittarius).
During the evening, Mars and Neptune lie in the southwest and Uranus lies in the south. At midnight, Uranus is in the west. Mercury, Venus, Jupiter, and Saturn can be seen in the southeast in the morning.
On New Year’s Day, three bright planets (Mercury, Venus, and Jupiter) and a waning crescent Moon will form a 35-degree-long span across the southeast at dawn.
Mercury brightens this month but after January 4th grows too low to be seen as it heads sunward. A waning crescent Moon passes three degrees north of the planet on that date. Mercury reaches superior conjunction on January 30th.
Venus rises more than 3.5 hours before sunrise on New Year’s Day for observers at 40 degrees north. The waning crescent Moon passes within five degrees of the planet that morning. Venus reaches maximum western elongation on January 6th. Venus, Jupiter, and Antares form a rough right triangle on January 19th. On January 22nd, Venus and Jupiter lie within 2.4 degrees of each other. Antares is located just a bit more than eight degrees from the pair. The two brightest planets are separated by a bit more than four degrees on January 26th. By the end of the month, that gap increases to over nine degrees. On the morning of January 31st, the waning crescent Moon lies between Venus and Jupiter and is situated about two degrees from Venus. During January, Venus decreases in apparent diameter from 26.3 arc seconds to 19.4 arc seconds but increases in illumination from 47% to 62%.
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 fades from magnitude +0.5 to magnitude +0.9 this month and shrinks to an apparent diameter of 6.2 arc seconds. A waxing crescent Moon passes five degrees south-southeast of Mars on the night of January 12th/13th. The Red Planet sets by 11:00 p.m. local time
Jupiter’s disk increases in apparent size from 31.8 arc seconds to 33.6 arc seconds as the planet brightens slightly from magnitude -1.8 to magnitude -1.9 during January. A slender waning crescent Moon lies about three degrees from Jupiter on the morning of January 3rd and about six degrees from the planet on January 30th. Data on Galilean satellite events is available online at http://www.shallowsky.com/jupiter/ and http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and on page 51 of the January 2019 issue of Sky & Telescope. Click on http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ or consult page 50 of the January 2019 issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot.
Saturn is in conjunction with the Sun on January 2nd and is not visible again until the second half of the month. The Ringed Planet attains an altitude of approximately seven degrees in the southeast about 45 minutes before sunrise on January 31st.
Uranus is located in extreme eastern Pisces. It’s situated 1.2 degrees north of the fourth-magnitude star Omicron Piscium during the first half of the month. By January 31st, Uranus has moved to a position 1.4 degrees north-northeast of the star. Uranus is stationary on January 7th and is at eastern quadrature on January 19th. The First Quarter Moon passes five degrees south-southeast of Uranus on January 14th. The seventh planet sets after midnight.
As twilight ends in early January, Neptune lies about 30 degrees above the southwestern horizon. The eighth planet can be found halfway between the fourth-magnitude stars Lambda and Phi Aquarii. On January 1st, it is located 14 arc minutes southeast of the sixth-magnitude star 81 Aquarii. By the end of the month, Neptune lies 55 arc minutes east of that star and 46 arc minutes north of the fifth-magnitude star 83 Aquarii. The waxing crescent Moon passes three degrees south of Neptune on January 10th.