Post by Dave Mitsky on Jan 2, 2016 1:55:09 GMT
January Celestial Calendar by Dave Mitsky
All times are UT (subtract five hours, and one calendar day when appropriate, for EST)
1/2 Last Quarter Moon occurs at 5:30; the Moon is at apogee, subtending 29' 33" from a distance of 404,277 kilometers (251,206 miles), at 11:53; the Earth is at perihelion (147,100,176 kilometers or 91,403,812 miles distant from the Sun) at 23:00
1/3 The Martian summer solstice occurs at 3:00; the Moon is 4.5 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 7:00; the Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to begin at 10:22; Mars is 1.4 degrees south-southwest of the Moon at 20:00
1/4 Mercury is at the ascending node at 2:00; the peak of the Quadrantid meteor shower (40 to 120 or more per hour) occurs at 8:00
1/5 The latest sunrise of 2016 at latitude 40 degrees north occurs today; Mercury is stationary in right ascension at 5:00; Pluto is in conjunction with the Sun at 22:00
1/7 Venus is 3.1 degrees south of the Moon at 1:00; Saturn is 3.3 degrees south of the Moon at 5:00; Uranus is at eastern quadrature at 12:00; Venus is 6.3 degrees north of the first-magnitude star Antares (Alpha Scorpii) at 16:00
1/8 The latest onset of morning twilight of 2016 at latitude 40 degrees north occurs today; Mercury is at perihelion (0.375 a.u. from the Sun) at 18:00; Jupiter is stationary in right ascension at 20:00
1/9 Venus is 0.08 degree north of Saturn, the second closest planetary appulse of 2016, at 4:00; Pluto is 3.1 degrees south of the moon at 19:00
1/10 New Moon (lunation 1151) occurs at 1:31; Mercury is 2.1 degrees south of the Moon at 18:00
1/13 Neptune is 2.2 degrees south-southeast of the Moon at 14:00
1/14 Mercury is in inferior conjunction at 14:00
1/15 The Moon is at perigee, subtending 32' 02" from a distance of 369,619 kilometers (229,671 miles), at 2:14
1/16 Uranus is 1.4 degrees north-northwest of the Moon at 7:00; First Quarter Moon occurs at 23:26; 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 22:56
1/18 Mercury is at its greatest heliocentric latitude north (7 degrees north of the ecliptic plane) at 23:00
1/19 Asteroid 2 Pallas is in conjunction with the Sun at 10:00
1/20 The Moon is 0.5 degree north-northwest of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation occurring in western Europe, southern Greenland, Canada, the United States, and northern Mexico, at 2:00; the Sun enters the constellation of Capricornus at 8:00
1/21 The Moon is 5.9 degrees south of the bright open cluster M35 in Gemini at 18:00
1/24 Full Moon (known as the Ice Moon, the Moon After Yule, the Old Moon, and the Wolf Moon) occurs in Gemini at 1:46; the Moon is 4.9 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 10:00
1/25 Comet C/2013 US10 (Catalina) is at opposition at 14:00; Mercury is stationary in right ascension at 19:00
1/26 The Moon is 2.4 degrees south-southwest of the first-magnitude star Regulus (Alpha Leonis) at 4:00
1/28 Jupiter is 1.3 degrees north-northeast of the Moon at 0:00; Venus is at its greatest declination south (-22.5 degrees) at 4:00
1/30 The Moon is at apogee, subtending 29' 45" from a distance of 404,553 kilometers (251,377 miles), at 9:00; Mercury is 0.5 degree north-northeast of Pluto at 15:00; the Moon is 4.8 degrees north-northeast of Spica at 15:00
Johannes Hevelius (1611-1687) was 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.
The Quadrantid meteor shower peaks on January 4th. The short-lived peak is predicted to occur during the early morning. A waning crescent Moon will be present but should not interfere greatly with watching the shower. This 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 48 of the January issue of Sky & Telescope or browse meteorshowersonline.com/quadrantids.html and earthsky.org/?p=4287 for more on the Quadrantids.
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 20.6-days old, is illuminated 61.6%, subtends 29.4 arc minutes, and is located in Virgo on January 1st at 0:00 UT. The Moon is at apogee on January 2nd and January 30th and at perigee on January 15th. The Moon attains its greatest northern declination (+18.3 degrees) for the month on January 22nd and its greatest southern declination (-18.4 degrees) on January 9th. Longitudinal libration is at a maximum of +4.9 degrees on January 24th and a minimum of -5.1 degrees on January 8th. Latitudinal libration is at a maximum of +6.6 degrees on January 21st and a minimum of -6.6 degrees on January 8th. The Moon, Mars, and Spica form a close triangle on the morning of January 3rd. At 4:00 UT on January 7th, the Moon, Venus, and Saturn lie within a 3.6-degree diameter circle, thus forming a trio. The 82%-illuminated waxing gibbous Moon occults Aldebaran on the evening of January 19th in North America. Consult lunar-occultations.com/iota/bstar/0120zc692.htm for further information. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons and 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 www.lunar-occultations.com/rlo/rays/rays.htm
The Sun is located in Sagittarius on January 1st. It enters Capricornus on January 20th.
Data (magnitude, apparent size, illumination, and distance from the Earth in astronomical units) for the planets and Pluto on January 1: Mercury (-0.4, 7.3", 49%, 0.92 a.u., Sagittarius), Venus (-4.0, 14.3", 77%, 1.17 a.u., Libra), Mars (+1.3, 5.6", 91%, 1.68 a.u., Virgo), Jupiter (-2.2, 39.0", 99%, 5.05 a.u., Leo), Saturn (+0.5, 15.3", 100%, 10.86 a.u., Ophiuchus), Uranus (+5.8, 3.5", 100%, 20.10 a.u. on December 16th, Pisces), Neptune (+7.9, 2.2", 100%, 30.68 a.u. on December 16th, Aquarius), Pluto (+14.3, 0.1", 100%, 33.99 a.u. on December 16th, Sagittarius).
During the evening, Mercury and Neptune lie in the southwest and Uranus in the south. At midnight, Jupiter is in the east. Mercury, Venus, and Saturn can be seen in the southeast, Mars in the south, and Jupiter in the southwest in the morning.
At midmonth, Venus rises at 5:00 a.m., Mars rises at 1:00 a.m., Jupiter rises at 10:00 p.m. and transits the meridian at 4:00 a.m., and Saturn rises at 4:00 a.m. local time for observers at latitude 40 degrees north.
The four brightest planets appear in the morning sky this month. A series of pairings between the Moon and Mars, the Moon and Venus, the Moon and Saturn, Venus and Saturn, Venus and Antares, Saturn and Antares, and the Moon and Antares take place in the morning sky during early January.
Mercury is visible during both evening twilight and morning twilight this month. From January 1st to January 9th, it is well-positioned in the evening sky. Mercury appears in the morning sky from January 20th to the end of the month. The speediest planet is at the ascending node on January 1st and is stationary on January 5th, with retrograde (westward) motion commencing, and January 25th, with direct (eastward) motion resuming. Perihelion occurs on January 8th. Mercury is in inferior conjunction on January 14th and attains greatest latitude north of the ecliptic plane on January 18th.
Venus shines brightly at magnitude -4.0 for most of the month. Venus lies three degrees south of the Moon on January 7th. The gap between Venus and Saturn decreases rapidly in early January. Venus is just 17 arc minutes away from the 63-times-fainter Saturn (magnitude +0.5) as the two planets rise in eastern North America on the morning of January 9th. Venus moves rapidly eastward during January, beginning the month slightly more than one degree from Acrab (Beta Scorpii) and ending it north of the Teapot’s handle in Sagittarius.
Earth is 0.983 a.u. distant from the Sun at perihelion on January 2nd. 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 increases 1.2 arc seconds in size and brightens by a half magnitude this month. It is 1.5 degrees south of the Moon on January 3rd. The Red Planet departs Capricornus and enters Aquarius on January 9th.
During January, Jupiter’s disk increases in size by 3.4 arc seconds to 42.4 arc seconds. It brightens from magnitude -2.2 to magnitude -2.4. Jupiter commences retrograde motion through eastern Leo on January 8th. The waning gibbous Moon passes 1.4 degrees south of Jupiter on the evening of January 27th (January 28th UT). Click on www.skyandtelescope.com/observing/interactive-sky-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. Data on Galilean satellite events is available online at www.shallowsky.com/jupiter/ and www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and on page 51 of the January issue of Sky & Telescope.
The north side of Saturn’s rings is visible again this year. The rings are tilted within one degree of 26 degrees throughout 2016. During January, the planet’s disk subtends over 15 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 is three degrees south of the Moon on January 7th. Saturn and Venus are at their closest in a decade on the morning of January 9th. For information on the satellites of Saturn, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
Uranus can be found two degrees south of the fourth-magnitude star Epsilon Piscium in southern Pisces.
Neptune is located in the southwestern sky at sunset. It lies about four degrees southwest of the fourth-magnitude star Lambda Aquarii. The eighth planet passes thirteen arc minutes due west of the seventh-magnitude star SAO 146230, which is situated between Lambda Aquarii and the fifth-magnitude star Sigma Aquarii, on January 19th, and five arc minutes due north of that star on January 26th.
See www.curtrenz.com/uranep.html for additional information on the two outer planets.
Finder charts for Uranus and Neptune can be found on page 49 of the September 2015 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 is in conjunction with the Sun on January 6th UT.
For more on the planets and how to locate them, browse www.nakedeyeplanets.com/
Asteroid 5 Astraea shines at ninth magnitude as it treks northwestward through Leo during January. It passes one degree due south of the first magnitude star Regulus (Alpha Leonis) and about the same distance north of the fourth-magnitude star 31 Leonis on January 25th. A number of asteroid occultations visible from North America take place this month. Asteroid 1173 Anchises occults an 8.8-magnitude star in southern Gemini on the night of January 1st-January 2nd. Asteroid 115 Thyra occults a 9.0-magnitude star in northern Gemini on the night of January 21st-January 22nd. Thyra (magnitude +9.9) is at opposition on January 22nd. Asteroid 866 Fatme occults a 9.5-magnitude star in central Gemini on the evening of January 23rd (January 24th UT). Asteroid 329 Svea occults a 9.5-magnitude star on the border of Orion and Monoceros late on the evening of January 27th (January 28th UT). See asteroidoccultation.com/2016_01_si.htm for further information about these events. Consult www.curtrenz.com/asteroids.html to learn more about a number of asteroids.
Comet C/2013 US10 (Catalina) travels northward at more than two degrees per day through Boötes, Canes Venatici, and Ursa Major this month. The comet comes within half a degree of the first-magnitude star Arcturus (Alpha Boötis) on the morning of January 1st. It passes to the east of the spiral galaxy M51 in Canes Venatici on January 14th and just to the west of the spiral galaxy M101 in Ursa Major on January 16th and January 17th. A finder chart appears on page 45 of the December issue of Sky & Telescope. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html for information on comets visible this month and in the near future.
A wealth of information on solar system celestial bodies is posted at www.curtrenz.com/astronomy.html and nineplanets.org/
Information on the celestial events transpiring each week can be found at astronomy.com/skythisweek and www.skyandtelescope.com/observing/sky-at-a-glance/
Free star maps for January can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
With the exception of June, Aldebaran is occulted by the Moon from at least some location on Earth every month in 2016.
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 (C). 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, 12th, 15th, 18th, 21st, 24th, 27th, and 30th. Consult page 50 of the January issue of Sky & Telescope for the times of the minima. For more on Algol, see stars.astro.illinois.edu/sow/Algol.html and www.solstation.com/stars2/algol3.htm
Information pertaining to 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 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.
All times are UT (subtract five hours, and one calendar day when appropriate, for EST)
1/2 Last Quarter Moon occurs at 5:30; the Moon is at apogee, subtending 29' 33" from a distance of 404,277 kilometers (251,206 miles), at 11:53; the Earth is at perihelion (147,100,176 kilometers or 91,403,812 miles distant from the Sun) at 23:00
1/3 The Martian summer solstice occurs at 3:00; the Moon is 4.5 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 7:00; the Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to begin at 10:22; Mars is 1.4 degrees south-southwest of the Moon at 20:00
1/4 Mercury is at the ascending node at 2:00; the peak of the Quadrantid meteor shower (40 to 120 or more per hour) occurs at 8:00
1/5 The latest sunrise of 2016 at latitude 40 degrees north occurs today; Mercury is stationary in right ascension at 5:00; Pluto is in conjunction with the Sun at 22:00
1/7 Venus is 3.1 degrees south of the Moon at 1:00; Saturn is 3.3 degrees south of the Moon at 5:00; Uranus is at eastern quadrature at 12:00; Venus is 6.3 degrees north of the first-magnitude star Antares (Alpha Scorpii) at 16:00
1/8 The latest onset of morning twilight of 2016 at latitude 40 degrees north occurs today; Mercury is at perihelion (0.375 a.u. from the Sun) at 18:00; Jupiter is stationary in right ascension at 20:00
1/9 Venus is 0.08 degree north of Saturn, the second closest planetary appulse of 2016, at 4:00; Pluto is 3.1 degrees south of the moon at 19:00
1/10 New Moon (lunation 1151) occurs at 1:31; Mercury is 2.1 degrees south of the Moon at 18:00
1/13 Neptune is 2.2 degrees south-southeast of the Moon at 14:00
1/14 Mercury is in inferior conjunction at 14:00
1/15 The Moon is at perigee, subtending 32' 02" from a distance of 369,619 kilometers (229,671 miles), at 2:14
1/16 Uranus is 1.4 degrees north-northwest of the Moon at 7:00; First Quarter Moon occurs at 23:26; 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 22:56
1/18 Mercury is at its greatest heliocentric latitude north (7 degrees north of the ecliptic plane) at 23:00
1/19 Asteroid 2 Pallas is in conjunction with the Sun at 10:00
1/20 The Moon is 0.5 degree north-northwest of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation occurring in western Europe, southern Greenland, Canada, the United States, and northern Mexico, at 2:00; the Sun enters the constellation of Capricornus at 8:00
1/21 The Moon is 5.9 degrees south of the bright open cluster M35 in Gemini at 18:00
1/24 Full Moon (known as the Ice Moon, the Moon After Yule, the Old Moon, and the Wolf Moon) occurs in Gemini at 1:46; the Moon is 4.9 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 10:00
1/25 Comet C/2013 US10 (Catalina) is at opposition at 14:00; Mercury is stationary in right ascension at 19:00
1/26 The Moon is 2.4 degrees south-southwest of the first-magnitude star Regulus (Alpha Leonis) at 4:00
1/28 Jupiter is 1.3 degrees north-northeast of the Moon at 0:00; Venus is at its greatest declination south (-22.5 degrees) at 4:00
1/30 The Moon is at apogee, subtending 29' 45" from a distance of 404,553 kilometers (251,377 miles), at 9:00; Mercury is 0.5 degree north-northeast of Pluto at 15:00; the Moon is 4.8 degrees north-northeast of Spica at 15:00
Johannes Hevelius (1611-1687) was 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.
The Quadrantid meteor shower peaks on January 4th. The short-lived peak is predicted to occur during the early morning. A waning crescent Moon will be present but should not interfere greatly with watching the shower. This 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 48 of the January issue of Sky & Telescope or browse meteorshowersonline.com/quadrantids.html and earthsky.org/?p=4287 for more on the Quadrantids.
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 20.6-days old, is illuminated 61.6%, subtends 29.4 arc minutes, and is located in Virgo on January 1st at 0:00 UT. The Moon is at apogee on January 2nd and January 30th and at perigee on January 15th. The Moon attains its greatest northern declination (+18.3 degrees) for the month on January 22nd and its greatest southern declination (-18.4 degrees) on January 9th. Longitudinal libration is at a maximum of +4.9 degrees on January 24th and a minimum of -5.1 degrees on January 8th. Latitudinal libration is at a maximum of +6.6 degrees on January 21st and a minimum of -6.6 degrees on January 8th. The Moon, Mars, and Spica form a close triangle on the morning of January 3rd. At 4:00 UT on January 7th, the Moon, Venus, and Saturn lie within a 3.6-degree diameter circle, thus forming a trio. The 82%-illuminated waxing gibbous Moon occults Aldebaran on the evening of January 19th in North America. Consult lunar-occultations.com/iota/bstar/0120zc692.htm for further information. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons and 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 www.lunar-occultations.com/rlo/rays/rays.htm
The Sun is located in Sagittarius on January 1st. It enters Capricornus on January 20th.
Data (magnitude, apparent size, illumination, and distance from the Earth in astronomical units) for the planets and Pluto on January 1: Mercury (-0.4, 7.3", 49%, 0.92 a.u., Sagittarius), Venus (-4.0, 14.3", 77%, 1.17 a.u., Libra), Mars (+1.3, 5.6", 91%, 1.68 a.u., Virgo), Jupiter (-2.2, 39.0", 99%, 5.05 a.u., Leo), Saturn (+0.5, 15.3", 100%, 10.86 a.u., Ophiuchus), Uranus (+5.8, 3.5", 100%, 20.10 a.u. on December 16th, Pisces), Neptune (+7.9, 2.2", 100%, 30.68 a.u. on December 16th, Aquarius), Pluto (+14.3, 0.1", 100%, 33.99 a.u. on December 16th, Sagittarius).
During the evening, Mercury and Neptune lie in the southwest and Uranus in the south. At midnight, Jupiter is in the east. Mercury, Venus, and Saturn can be seen in the southeast, Mars in the south, and Jupiter in the southwest in the morning.
At midmonth, Venus rises at 5:00 a.m., Mars rises at 1:00 a.m., Jupiter rises at 10:00 p.m. and transits the meridian at 4:00 a.m., and Saturn rises at 4:00 a.m. local time for observers at latitude 40 degrees north.
The four brightest planets appear in the morning sky this month. A series of pairings between the Moon and Mars, the Moon and Venus, the Moon and Saturn, Venus and Saturn, Venus and Antares, Saturn and Antares, and the Moon and Antares take place in the morning sky during early January.
Mercury is visible during both evening twilight and morning twilight this month. From January 1st to January 9th, it is well-positioned in the evening sky. Mercury appears in the morning sky from January 20th to the end of the month. The speediest planet is at the ascending node on January 1st and is stationary on January 5th, with retrograde (westward) motion commencing, and January 25th, with direct (eastward) motion resuming. Perihelion occurs on January 8th. Mercury is in inferior conjunction on January 14th and attains greatest latitude north of the ecliptic plane on January 18th.
Venus shines brightly at magnitude -4.0 for most of the month. Venus lies three degrees south of the Moon on January 7th. The gap between Venus and Saturn decreases rapidly in early January. Venus is just 17 arc minutes away from the 63-times-fainter Saturn (magnitude +0.5) as the two planets rise in eastern North America on the morning of January 9th. Venus moves rapidly eastward during January, beginning the month slightly more than one degree from Acrab (Beta Scorpii) and ending it north of the Teapot’s handle in Sagittarius.
Earth is 0.983 a.u. distant from the Sun at perihelion on January 2nd. 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 increases 1.2 arc seconds in size and brightens by a half magnitude this month. It is 1.5 degrees south of the Moon on January 3rd. The Red Planet departs Capricornus and enters Aquarius on January 9th.
During January, Jupiter’s disk increases in size by 3.4 arc seconds to 42.4 arc seconds. It brightens from magnitude -2.2 to magnitude -2.4. Jupiter commences retrograde motion through eastern Leo on January 8th. The waning gibbous Moon passes 1.4 degrees south of Jupiter on the evening of January 27th (January 28th UT). Click on www.skyandtelescope.com/observing/interactive-sky-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. Data on Galilean satellite events is available online at www.shallowsky.com/jupiter/ and www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and on page 51 of the January issue of Sky & Telescope.
The north side of Saturn’s rings is visible again this year. The rings are tilted within one degree of 26 degrees throughout 2016. During January, the planet’s disk subtends over 15 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 is three degrees south of the Moon on January 7th. Saturn and Venus are at their closest in a decade on the morning of January 9th. For information on the satellites of Saturn, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
Uranus can be found two degrees south of the fourth-magnitude star Epsilon Piscium in southern Pisces.
Neptune is located in the southwestern sky at sunset. It lies about four degrees southwest of the fourth-magnitude star Lambda Aquarii. The eighth planet passes thirteen arc minutes due west of the seventh-magnitude star SAO 146230, which is situated between Lambda Aquarii and the fifth-magnitude star Sigma Aquarii, on January 19th, and five arc minutes due north of that star on January 26th.
See www.curtrenz.com/uranep.html for additional information on the two outer planets.
Finder charts for Uranus and Neptune can be found on page 49 of the September 2015 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 is in conjunction with the Sun on January 6th UT.
For more on the planets and how to locate them, browse www.nakedeyeplanets.com/
Asteroid 5 Astraea shines at ninth magnitude as it treks northwestward through Leo during January. It passes one degree due south of the first magnitude star Regulus (Alpha Leonis) and about the same distance north of the fourth-magnitude star 31 Leonis on January 25th. A number of asteroid occultations visible from North America take place this month. Asteroid 1173 Anchises occults an 8.8-magnitude star in southern Gemini on the night of January 1st-January 2nd. Asteroid 115 Thyra occults a 9.0-magnitude star in northern Gemini on the night of January 21st-January 22nd. Thyra (magnitude +9.9) is at opposition on January 22nd. Asteroid 866 Fatme occults a 9.5-magnitude star in central Gemini on the evening of January 23rd (January 24th UT). Asteroid 329 Svea occults a 9.5-magnitude star on the border of Orion and Monoceros late on the evening of January 27th (January 28th UT). See asteroidoccultation.com/2016_01_si.htm for further information about these events. Consult www.curtrenz.com/asteroids.html to learn more about a number of asteroids.
Comet C/2013 US10 (Catalina) travels northward at more than two degrees per day through Boötes, Canes Venatici, and Ursa Major this month. The comet comes within half a degree of the first-magnitude star Arcturus (Alpha Boötis) on the morning of January 1st. It passes to the east of the spiral galaxy M51 in Canes Venatici on January 14th and just to the west of the spiral galaxy M101 in Ursa Major on January 16th and January 17th. A finder chart appears on page 45 of the December issue of Sky & Telescope. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html for information on comets visible this month and in the near future.
A wealth of information on solar system celestial bodies is posted at www.curtrenz.com/astronomy.html and nineplanets.org/
Information on the celestial events transpiring each week can be found at astronomy.com/skythisweek and www.skyandtelescope.com/observing/sky-at-a-glance/
Free star maps for January can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
With the exception of June, Aldebaran is occulted by the Moon from at least some location on Earth every month in 2016.
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 (C). 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, 12th, 15th, 18th, 21st, 24th, 27th, and 30th. Consult page 50 of the January issue of Sky & Telescope for the times of the minima. For more on Algol, see stars.astro.illinois.edu/sow/Algol.html and www.solstation.com/stars2/algol3.htm
Information pertaining to 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 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.