February Celestial Calendar by Dave Mitsky
All times, unless otherwise noted, are UT (subtract five hours and, when appropriate, one calendar day for EST)
2/1 The Moon is 4.2 degrees southeast of Uranus at 7:00; the Lunar X (the Purbach or Werner Cross), an X-shaped clair-obscure illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to be fully formed at 10:32; Mars is at the descending node through the ecliptic plane at 18:00
2/2 The astronomical cross-quarter day (i.e., a day half way between a solstice and an equinox) known as Imbolc, Candlemas, or Groundhog Day occurs today; First Quarter Moon occurs at 1:42; asteroid 4 Vesta is 0.5 degree south of the Moon, with an occultation occurring in western Canada, Alaska, eastern Russia, Japan, China, the northern Philippines, southern Asia, and eastern Afghanistan, at 9:00
2/3 The Moon is 7.2 degrees southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 14:00
2/4 The Moon is 3.0 degrees north of the first-magnitude star Aldebaran (Alpha Tauri) at 7:00
2/5 The Moon is 1.4 degrees south of the bright open cluster M35 in Gemini at 23:00
2/7 The Moon is 8.9 degrees south of the first-magnitude star Castor (Alpha Geminorum) at 9:00; the Moon is 5.3 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 13:00; Mercury is at the ascending node through the ecliptic plane at 13:00
2/8 The Moon is 1.3 degrees north-northeast of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 12:00
2/9 Full Moon (known as the Hunger, Snow, or Storm Moon) occurs at 7:33
2/10 The Moon is 3.6 degrees north-northeast of the first-magnitude star Regulus (Alpha Leonis) at 0:00; Mercury is at greatest eastern elongation (18.2 degrees) at 14:00; the Moon is at perigee, subtending 33' 09" from a distance of 360,461 kilometers (223,980 miles), at 20:28
2/11 The equation of time, the difference between mean solar time (as indicated by clocks) and apparent solar time (as indicated by sundials), is at a minimum of -14.24 minutes at 22:00
2/12 Mercury is at perihelion (0.3075 astronomical units from the Sun) at 5:00
2/13 Saturn is at the descending node through the ecliptic plane at 3:00; asteroid 4 Vesta is stationary at 7:00; the Moon is 0.6 degree north of the asteroid 4 Vesta, with an occultation occurring in northern South America, the Caribbean, Central America, and North America with the exception of northeast Canada, at 10:00; the Moon is 7.0 degrees north-northeast of Spica at 16:00
2/15 Venus is at the ascending node through the ecliptic plane at 6:00; Mercury (magnitude +0.5) is 5.8 degrees west of Neptune (magnitude +8.0) at 21:00; Last Quarter Moon occurs at 22:18
2/16 Mercury is stationary in right ascension and begins retrograde motion at 10:00
2/17 Mercury stationary in longitude and begins retrograde motion at 1:00; the Sun enters Aquarius (longitude 327.9 degrees on the ecliptic) at 3:00; the Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to be visible at 13:27
2/18 The Moon is 0.8 degree north of Mars, with an occultation occurring in the Azores, the southern portion of Greenland, northern South America, the Caribbean, most of Central America, and North America with the exception of western Canada and Alaska, at 13:00
2/19 The Moon is at the descending node (longitude 277.3 degrees) at 0:00; the Sun’s longitude is 330 degrees at 5:00; the Moon is 0.9 degree south of Jupiter, with an occultation occurring in southern South America and Antarctica, at 20:00
2/20 The Moon is 1.7 degrees south of Saturn at 14:00; Mars is at its southernmost declination (-23.7 degrees) at 16:00
2/22 Mercury is at its northernmost latitude from the ecliptic plane (7.0 degrees) at 10:00
2/23 New Moon (lunation 1202) occurs at 15:32
2/24 The Moon is 8.1 degrees southeast of Mercury at 1:00; the Moon is 3.8 degrees southeast of Neptune at 19:00
2/26 Mercury is in inferior conjunction with the Sun (0.637 astronomical units from the Earth, latitude 6.6 degrees) at 2:00; Jupiter is at the descending node through the ecliptic plane at 3:00; the Moon is at apogee, subtending 29' 25" from a distance of 406,278 kilometers (252,450 miles), at 11:34
2/27 The Moon is 5.8 degrees southeast of Venus at 18:00
2/28 The Moon is 4.0 degrees south of Uranus at 12:00
Nicolas Copernicus (1473-1543), Galileo Galilei (1564-1642), Jacques Cassini (1677-1756), William Huggins (1824-1910), John Dreyer (1852-1926), Bernard Lyot (1897-1952), and Clyde Tombaugh (1906-1997) were born this month.
Nicolas Louis de Lacaille discovered the open cluster NGC 3228 in Vela on February 11, 1752. Nicolas Louis de Lacaille discovered the face-on barred spiral galaxy M83 in Hydra on February 23, 1752. Johann Bode discovered the globular cluster M53 in Coma Berenices on February 3, 1775. The planetary nebula M97 in Ursa Major was discovered by Pierre François André Méchain on February 16, 1781. Caroline Herschel discovered the open cluster NGC 2360 in Canis Major on February 26, 1783. William Herschel discovered the face-on barred spiral galaxy NGC 4027 in Corvus on February 7, 1785. William Herschel’s 40-foot-focal-length telescope saw first light on February 19, 1787. Clyde Tombaugh discovered Pluto on February 18, 1930. James Hey detected radio waves emitted by the Sun on February 27, 1942. Gerald Kuiper discovered the Uranian satellite Miranda (magnitude +15.8) on February 16, 1948. The first pulsar, PSR B1919+21, was discovered by Jocelyn Bell Burnell and Antony Hewish on February 24, 1967. Supernova 1987A was discovered by Ian Shelton, Oscar Duhalde, and Albert Jones on February 23, 1987.
The zodiacal light should be visible from a dark location in the west after evening twilight for two weeks starting on February 11th. Click on https://www.atoptics...ighsky/zod1.htm for more on the zodiacal light.
Information on passes of the ISS, the USAF’s X-37B, the HST, and other satellites can be found at http://www.heavens-above.com/
The Moon is 6.9 days old, is illuminated 37.9%, subtends 29.9', and is located in the constellation of Pisces at 0:00 UT on February 1st. The Moon attains its greatest northern declination (+23.2 degrees) for the month on February 7th and its greatest southern declination (-23.2 degrees) on February 19th. Longitudinal libration is at a maximum of +6.6 degrees on February 17th and at a minimum of -7.0 degrees on February 5th. Latitudinal libration is at a maximum of +6.6 degrees on February 26th and a minimum of -6.6 degrees on December 12th. New Moon occurs on February 23rd. The Moon is at perigee (a distance of 56.52 Earth-radii) on February 10th and is at apogee (a distance of 63.70 Earth-radii) on February 26th. The Moon is about one degree from Graffias (Beta Scorpii) on the morning of February 16th. The waning crescent Moon joins Mars, Jupiter, and Saturn in the southeastern sky on the mornings of February 18th, February 19th, and February 20th. The Lunar X occurs on February 1st and the Curtiss Cross on February 17th. From certain parts of the world, the Moon occults 4 Vesta, 3 Juno, Mars, and Jupiter on February 2nd, February 13th, February 18th, and February 19th respectively. Browse http://www.lunar-occ...ota/iotandx.htm for information on lunar occultation 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. Consult http://time.unitariu...moon/where.html or download http://www.ap-i.net/avl/en/start for current information on the Moon. See https://svs.gsfc.nasa.gov/4768 for a lunar phase and libration calculator and https://svs.gsfc.nasa.gov/4768 for the Lunar Reconnaissance Orbiter Camera (LROC) Quickmap. Click on https://www.calendar...r/2020/february for a lunar phase calendar for this month. Times and dates for the lunar crater light rays predicted to occur this month are available at http://www.lunar-occ...o/rays/rays.htm
The Sun is located in the constellation of Capricornus on February 1st. It enters Aquarius on February 16th.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on February 1: Mercury (magnitude -1.0, 5.6", 85% illuminated, 1.19 a.u., Capricornus), Venus (magnitude -4.1, 15.3", 73% illuminated, 1.09 a.u., Aquarius), Mars (magnitude +1.4, 4.8", 93% illuminated, 1.95 a.u., Ophiuchus), Jupiter (magnitude -1.9, 32.5", 100% illuminated, 6.07 a.u., Sagittarius), Saturn (magnitude +0.6, 15.1", 100% illuminated, 10.97 a.u., Sagittarius), Uranus (magnitude +5.8, 3.5", 100% illuminated, 20.17 a.u. on February 15th, Aries), Neptune (magnitude +8.0, 2.2", 100% illuminated, 30.85 a.u. on February 15th, Aquarius), and Pluto (magnitude +14.4, 0.1", 100% illuminated, 34.81 a.u. on February 15th, Sagittarius).
Mercury, Venus, and Neptune can be seen in the west and Uranus in the southwest in the evening sky. In the morning sky, Mars, Jupiter, and Saturn lie in the southeast.
Mercury, Venus, Mars, Jupiter, and Saturn all pass through the ecliptic during February.
Mercury is at the ascending node on February 7th. It reaches greatest eastern elongation on February 10th and perihelion on February 12th. This will be a short but respectable evening apparition of the planet for northern hemisphere observers with the planet positioned ten degrees above the horizon for the first two weeks of February. Mercury will shine at brighter than zero magnitude during the first half of the month. Mercury is stationary on February 16th and is at heliocentric latitude north on February 22th. The speediest planet will dim dramatically as it approaches inferior conjunction on the evening of February 25th (February 26th UT).
Venus increases 15 degrees in declination during the month, rising from nearly 35 degrees to slightly more than 41 degrees in altitude at sunset from 40 degrees north. It decreases in illumination from 73 to 63% but grows in angular size from 15 to 19 arc seconds. The brightest planet crosses the celestial equator on February 9th. On February 15th, it’s at the ascending node. The Moon passes six degrees north of Venus on February 27th. Venus sets approximately three and three-quarters hours after the Sun by the end of the month.
Mars passes the descending node of its orbit, moving to the south of the orbital plane of the Earth, and enters southern ecliptic latitudes on February 1st. The apparent diameter of the planet exceeds five arc seconds on February 10th. Mars enters Sagittarius on February 11th. Mars passes between M8 (the Lagoon Nebula) and M20 (the Trifid Nebula) on February 17th. The waning crescent Moon passes less than one degree north of Mars on February 18th. A short article on the occultation that will occur for much of the continental United States, Canada, and parts of Central America can be found on page 50 of the February 2020 issue of Sky & Telescope.
As February begins, Jupiter rises 90 minutes before sunrise. It brightens from magnitude -1.9 to magnitude -2.0 and increases in apparent diameter from 32.5 arc seconds to 34.1 arc seconds this month. The waning crescent Moon passes just less one degree to the south of Jupiter on February 19th. The gas giant planet is at the descending node on February 26th. 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 February 2020 issue of Sky & Telescope. Click on http://www.skyandtel...watching-tools/ or consult pages 50 and 51 of the February 2020 issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot.
The Ringed Planet crosses the ecliptic on February 13th. Saturn departs Sagittarius and enters Capricornus in the middle of the month. The waning crescent Moon passes less than two degrees south of Saturn on February 20th. As the month ends, Saturn’s ring system spans 35 arc seconds and is inclined 22 degrees from edge-on. For information on the satellites of Saturn, browse http://www.skyandtel...watching-tools/
Uranus is located about 12 degrees south of the second-magnitude star Hamal (Alpha Arietis). The ice giant sets around midnight local time early in the month and about two hours earlier as February draws to a close. Uranus and Venus are separated by about eight degrees on February 29th. Visit http://www.nakedeyep....com/uranus.htm for a finder chart.
Neptune lies six degrees west of Venus and 18 arc minutes west of the class M red giant star Phi Aquarii (magnitude 4.2) on February 1st. By February 10th, Neptune is positioned just 2.3 arc minutes north of the star. Mercury and Neptune are in quasiconjunction on February 15th. Neptune disappears from view by the middle of the month. Browse http://www.nakedeyep...com/neptune.htm for a finder chart.
Finder charts for Uranus and Neptune are also available online at https://s22380.pcdn....020_updated.pdf
See https://curtrenz.com/uranep.html for additional information on the two outer planets.
The dwarf planet Pluto is not visible this month.
A guide to planetary observing for the year by the British magazine The Sky at Night is posted at https://www.skyatnig...nets-night-sky/
For more on the planets and how to locate them, browse http://www.nakedeyeplanets.com/
Comet C/2017 T2 (PanSTARRS) is located a degree northwest of NGC 869 (the western half of the Double Cluster) on February 1st. By the middle of February, the comet is located a degree to the west of the open cluster Stock 2 (the Muscle Man Cluster). It can be found several degrees west of IC 1805 (the Heart Nebula) and IC 1848 (the Soul Nebula) as the month ends. Comet PanSTARRS may brighten to magnitude +8.8 by the end of February. An article and finder charts appear on pages 48 and 49 of the February 2020 issue of Sky & Telescope. Visit http://cometchasing.skyhound.com/ and http://www.aerith.ne...t/future-n.html for additional information on comets visible this month.
Asteroid 4 Vesta shines at eighth magnitude as it exits Aries and enters Taurus this month. The First Quarter Moon occults 4 Vesta on February 1st for observers in Alaska and western Canada. Asteroids brighter than magnitude +11.0 that reach opposition this month include 37 Fides (magnitude +10.1) on February 2nd and 30 Urania (magnitude +10.6) on February 29th. A finder chart for 37 Fides can be found on page 49 of the February 2020 issue of Sky & Telescope. Consult http://asteroidoccul.../2020_02_si.htm for information on asteroid occultation events taking place this month. Visit http://www.curtrenz.com/asteroids.html to learn more about a number of asteroids
A wealth of information on solar system celestial bodies is posted at http://www.curtrenz.com/astronomy.html and http://nineplanets.org/
The major meteor showers that will occur this year are discussed at https://www.skyandte...howers-in-2020/
Various events taking place within our solar system are discussed at http://www.bluewater...ed-4/index.html
Information on the celestial events transpiring each week can be found at http://astronomy.com/skythisweek and http://www.skyandtel...ky-at-a-glance/
A monthly podcast on various astronomical topics is available at https://www.skyandte...onomy-podcasts/
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from 2.1 to 3.4, on February 3rd, 6th, 9th, 11th, 14th, 17th, 20th, 23rd, 26th, and 29th. Consult page 50 of the February 2020 issue of Sky & Telescope for the times of the minima. The Demon Star is at minimum brightness for approximately two hours centered at 12:21 a.m. EST on February 6th (4:21 UT), at 9:10 p.m. EST on February 8th (2:10 UT on February 9th), at 10:55 p.m. EST on February 28th (3:55 UT on February 29th). For more on Algol, see http://stars.astro.i.../sow/Algol.html and http://www.solstatio...ars2/algol3.htm
Information on observing some of the more prominent Messier galaxies is available at http://www.cloudynig...ur-astronomers/
Finder charts for the Messier objects and other deep-sky objects are posted at https://freestarcharts.com/messier and https://freestarcharts.com/ngc-ic and https://www.cambridg...s_january-march
Telrad finder charts for the Messier Catalog and the SAC’s 110 Best of the NGC are posted at http://www.astro-tom...essier_maps.htm and http://sao64.free.fr...ataloguesac.pdf
Deep-sky object list generators can be found at https://dso-browser.com/ and http://www.virtualcolony.com/sac/ and http://tonightssky.com/MainPage.php
Free sky atlases can be downloaded at http://www.deepskywa...-atlas-full.pdf and https://allans-stuff.com/triatlas/
Forty binary and multiple stars for February: 41 Aurigae, Struve 872, Otto Struve 147, Struve 929, 56 Aurigae (Auriga); Nu-1 Canis Majoris, 17 Canis Majoris, Pi Canis Majoris, Mu Canis Majoris, h3945, Tau Canis Majoris (Canis Major); Struve 1095, Struve 1103, Struve 1149, 14 Canis Minoris (Canis Minor); 20 Geminorum, 38 Geminorum, Alpha Geminorum (Castor), 15 Geminorum, Lambda Geminorum, Delta Geminorum, Struve 1108, Kappa Geminorum (Gemini); 5 Lyncis, 12 Lyncis, 19 Lyncis, Struve 968, Struve 1025 (Lynx); Epsilon Monocerotis, Beta Monocerotis, 15 (S) Monocerotis (Monoceros); Struve 855 (Orion); Struve 1104, k Puppis, 5 Puppis (Puppis)
Notable carbon star for February: BL Orionis (Orion)
Fifty deep-sky objects for February: NGC 2146, NGC 2403 (Camelopardalis); M41, NGC 2345, NGC 2359, NGC 2360, NGC 2362, NGC 2367, NGC 2383 (Canis Major); M35, NGC 2129, NGC 2158, NGC 2266, NGC 2355, NGC 2371-72, NGC 2392, NGC 2420 (Gemini); NGC 2419 (Lynx); M50, NGC 2232, NGC 2237, NGC 2238, NGC 2244, NGC 2245, NGC 2251, NGC 2261, NGC 2264, NGC 2286, NGC 2301, NGC 2311, NGC 2324, NGC 2335, NGC 2345, NGC 2346, NGC 2353 (Monoceros); NGC 2169, NGC 2174, NGC 2194 (Orion); M46, M47, M93, Mel 71, NGC 2421, NGC 2423, NGC 2438, NGC 2439, NGC 2440, NGC 2467, NGC 2506, NGC 2509 (Puppis)
Top ten binocular deep-sky objects for February: M35, M41, M46, M47, M50, M93, NGC 2244, NGC 2264, NGC 2301, NGC 2360
Top ten deep-sky objects for February: M35, M41, M46, M47, M50, M93, NGC 2261, NGC 2362, NGC 2392, NGC 2403
Challenge deep-sky object for February: IC 443 (Gemini)
The objects listed above are located between 6:00 and 8:00 hours of right ascension.