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February 2021 Celestial Calendar

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#1 Dave Mitsky

Dave Mitsky


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Posted 01 February 2021 - 11:35 PM

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   Mars is at eastern quadrature (90 degrees from the Sun) at 10:00
2/2   Asteroid 18 Melpomene (magnitude +9.4) is at opposition in Cancer at 7:00
2/3   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; the Moon is 6.2 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 6:00; the Moon is at perigee, subtending 32' 17" from a distance of 370,116 kilometers (229,980 miles), at 19:03
2/4   Last Quarter Moon occurs at 17:37
2/5   The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to be visible at 21:42
2/6   Venus (magnitude -3.9) is 0.4 degrees southeast of Saturn (magnitude +0.7) at 8:00; Venus, Jupiter, and Saturn lie within a circle with a diameter of 5.4 degrees at 9:00; the Moon is 5.3 degrees north-northeast of the first-magnitude star Antares (Alpha Scorpii) at 12:00
2/7   The Moon is at the descending node (longitude 258.2 degrees) at 1:00; the Martian northern hemisphere vernal equinox occurs at 11:00
2/8   Mercury is at its northernmost latitude from the ecliptic plane (7.0 degrees) at 7:00; Mercury is at inferior conjunction with the Sun (0.652 astronomical units from Earth, latitude 7.0 degrees) at 14:00
2/9   Asteroid 2 Pallas is in conjunction with the Sun at 20:00
2/10 The Moon is 3.0 degrees south of Saturn at 11:00; the Moon, Venus, and Saturn lie within a circle with a diameter of 5.2 degrees at 16:00; the Moon is 3.0 degrees south of Venus at 20:00; the Moon, Venus, and Jupiter lie within a circle with a diameter of 3.6 degrees at 23:00
2/11 The Moon is 3.6 degrees southeast of Jupiter at 0:00; 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 -14.23 minutes at 3:00; the Moon is 8.0 degrees southeast of Mercury at 8:00; Venus is 0.4 degrees south of Jupiter at 12:00; New Moon (lunation 1214) occurs at 19:06
2/13 Mercury (magnitude +2.7) is 4.6 degrees north-northwest of Venus (magnitude -3.9) at 10:00; Mercury, Venus, and Jupiter lie within a circle with a diameter of 4.6 degrees at 11:00; the Moon is 4.0 degrees south of Neptune at 17:00; Mercury is 4.0 degrees north of Jupiter at 19:00
2/15 Mercury (magnitude +2.0) is 3.9 degrees north-northwest of Jupiter (magnitude -2.0) at 14:00
2/16 The Sun enters Aquarius (longitude 327.9 degrees on the ecliptic) at 9:00
2/17 The Moon is 2.8 degrees southeast of Uranus at 19:00
2/18 The Moon is at apogee, subtending 29' 32" from a distance of 404,467 kilometers (251,324 miles), at 10:22; the Sun's longitude is 330 degrees at 11:00
2/19 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 8:30; the Moon is 5.5 degrees southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 18:00; First Quarter Moon occurs at 18:47
2/20 Venus is at aphelion (0.7282 astronomical units from the Sun) at 8:00; the Moon is 4.9 degrees north of Aldebaran at 12:00; Mercury is stationary, with prograde or direct (eastward) motion to commence, at 13:00
2/22 The Moon is 0.4 degrees north of the bright open cluster M35 in Gemini at 8:00; asteroid 29 Amphitrite (magnitude +9.2) is at opposition in Leo at 16:00
2/23 Mercury is 4.1 degrees northeast of Saturn at 8:00; the Moon is 7.3 degrees south of the first-magnitude star Castor (Alpha Geminorum) at 21:00
2/24 The Moon is 3.7 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 2:00
2/25 The Moon is 2.6 degrees north-northeast of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 3:00
2/26 The Moon is 4.3 degrees north-northeast of the first-magnitude star Regulus (Alpha Leonis) at 18:00
2/27 The Full Moon (known as the Hunger, Snow, or Storm Moon) occurs at 8:17


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 in the west after evening twilight from a dark location during the first two weeks of February.  Click on https://www.atoptics...ighsky/zod1.htm for more on the zodiacal light.


The major meteor showers occurring this year are discussed at https://skyandtelesc...howers-in-2021/


Information on passes of the ISS, the USAF’s X-37B, the HST, Starlink, and other satellites can be found at http://www.heavens-above.com/


The Moon is 18.6 days old, is illuminated 89.4%, subtends 32.0', and is located in the constellation of Virgo at 0:00 UT on February 1st.  The Moon attains its greatest northern declination (+25.1 degrees) for the month on February 23rd and its greatest southern declination (-24.9 degrees) on February 9th.  Longitudinal libration is at a maximum of +4.6 degrees on February 12th and at a minimum of -6.3 degrees on February 24th.  Latitudinal libration is at a maximum of +6.6 degrees on February 14th and a minimum of -6.6 degrees on December 1st and -6.5 degrees on February 28th.  Favorable librations for the following lunar features occur on the indicated dates: Crater Hausen on February 1st, Crater Le Gentil on February 2nd, Crater Cabeus on February 3rd, and Crater Hayn on February 15th.  New Moon occurs on February 11th.  The Moon is at perigee (a distance of 58.03 Earth-radii) on February 3rd and is at apogee (a distance of 63.41 Earth-radii) on February 18th.  The Curtiss Cross occurs on February 5th and the Lunar X on February 19th.  The Moon will occult the fourth-magnitude star Omega Ophiuchi on the morning of February 6th, the bright open cluster M35 on the morning of February 22nd, and the fourth-magnitude star Kappa Geminorum on the evening of February 23rd, as described on page 50 of the February issue of Sky & Telescope.  Browse http://www.lunar-occ...ota/iotandx.htm for additional information on lunar occultation events.  Visit https://saberdoesthe...does-the-stars/ for tips on spotting extreme crescent Moons and https://curtrenz.com/moon.html for Full Moon and other lunar data.  Consult http://time.unitariu...moon/where.html for current information on the Moon.  Visit http://www.ap-i.net/avl/en/start to download the free Virtual Moon Atlas.  Browse https://skyandtelesc...ads/MoonMap.pdf for a lunar map.  See https://svs.gsfc.nasa.gov/4874 for a lunar phase and libration calculator and https://quickmap.lro...2vIBvAXwF1SizSg for the Lunar Reconnaissance Orbiter Camera (LROC) Quickmap.  Click on https://www.calendar...r/2021/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 +1.1, 8.8", 18% illuminated, 0.76 a.u., Capricornus), Venus (magnitude -3.9, 10.1", 98% illuminated, 1.65 a.u., Sagittarius), Mars (magnitude +0.4, 7.9", 89% illuminated, 1.19 a.u., Aries), Jupiter (magnitude -2.0, 32.5", 100% illuminated, 6.07 a.u., Capricornus), Saturn (magnitude +0.6, 15.2", 100% illuminated, 10.96 a.u., Capricornus), Uranus (magnitude +5.8, 3.5", 100% illuminated, 20.07 a.u. on February 15th, Aries), Neptune (magnitude +8.0, 2.2", 100% illuminated, 30.83 a.u. on February 15th, Aquarius), and Pluto (magnitude +14.4, 0.1", 100% illuminated, 35.07 a.u. on February 15th, Sagittarius). 


Mars and Uranus can be seen in the southwest and Neptune in the west in the evening sky.  Mars is in the west at midnight.  In the morning sky, Mercury, Venus, Jupiter and Saturn lie in the east. 


During February, four planets converge in the east at morning twilight.  Venus, Jupiter, and Saturn lie within a circle with a diameter of 5.4 degrees on February 6th.  On February 10th, the Moon, Venus, and Saturn lie within a circle with a diameter of 5.2 degrees and the Moon, Venus, and Jupiter lie within a circle with a diameter of 3.6 degrees.  Mercury, Venus, and Jupiter lie within a circle with a diameter of 4.6 degrees on February 13th.


Mercury is inferior conjunction on February 8th.  It also attains its greatest heliocentric latitude north on that day.  Mercury returns to the morning sky in the second half of February.  It's positioned three degrees west of Jupiter on the morning of February 28th.  Saturn lies 5.5 degrees to the west of Mercury on that date.  This will be the best morning apparition of the speediest planet for southern hemisphere observers this year. 


Venus changes little in apparent size or brightness this month.  Venus passes 0.4 degrees south of Saturn on February 6th and 0.4 degrees south of Jupiter on February 11th.


Mars is at eastern quadrature on February 1st.  As the distance between the Earth and Mars increases, observing surface features becomes very hard.  Syrtis Major, the most prominent albedo feature, may be visible with difficulty until local midnight during the first five days of the month.  The vernal equinox occurs in the Martian northern hemisphere on February 7th.  Mars enters Taurus on February 23rd.  The Red Planet passes approximately three degrees southwest of the bright open cluster M45 on February 28th.  On the same date, Mars is almost 1.5 astronomical units from the Earth and subtends only 6.4 arc seconds, while shining at just magnitude +0.9.


Jupiter emerges into morning twilight as a naked-eye object around February 19th.  Jupiter (magnitude -2.0) forms an isosceles triangle with Mercury (magnitude +0.3) and Saturn (magnitude +0.7) low in the east-southeast 30 minutes before sunrise on February 25th.


The Ringed Planet reenters the dawn sky around the middle of the month.  When Venus passes 0.4 degrees south of Saturn on February 6th, the two planets are just 11 degrees from the Sun.  On the morning of February 20th,


Saturn and Mercury are separated by 4.4 degrees as the two planets rise.  Jupiter forms a triangle with those two planets and is 7.7 degrees east of Saturn when it rises some 22 minutes later.


Uranus is located about 10.5 degrees south of the second-magnitude star Hamal (Alpha Arietis).  Uranus and Mars are separated by approximately 6.5 degrees as February begins.  A waxing crescent Moon passes three degrees south of Uranus on February 17th.  Visit http://www.nakedeyep....com/uranus.htm for a finder chart.


Neptune lies about two degrees northeast of the fourth-magnitude star Phi Aquarii on February 1st.  A slender waxing crescent Moon passes four degrees south of Neptune on February 13th. The eighth planet 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://skyandtelesc...W_WebFinder.pdf


See http://www.curtrenz.com/uranep.html for additional information on the two outer planets.


Click on http://www.skyandtel...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.


A summary on the planets for February can be found at https://skynews.ca/f...ts-at-a-glance/


The graphic at https://www.timeandd...lanets/distance displays the apparent and comparative sizes of the planets, along with their magnitudes and distances, for a given date and time.


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/2021 A2 (NEOWISE) travels northwestward from Puppis to Auriga during February.  The faint periodic comet 88P/Howell heads northeastward through Aquarius and Pisces.  It enters Cetus at the end of February.  Two other faint periodic comets, 17P/Holmes and 141P/Machholz 2, lie nearby in the vicinity of the Circlet of Pisces and Cetus respectively.  Visit http://cometchasing.skyhound.com/ and http://www.aerith.ne...t/future-n.html and https://cobs.si/ for information on these and other comets visible this month.


Asteroids 18 Melpomene and 60 Echo travel northwestward through southern Cancer this month on roughly parallel trajectories.  Asteroid 10 Echo passes just south of the open cluster M67 from February 5th through February 8th.  Asteroid 18 Melpomene lies about one degree north of M67 during that period.  Asteroids brighter than magnitude +11.0 that reach opposition this month include 60 Echo (magnitude +10.3) on February 1st, 18 Melpomene (magnitude +9.4) on February 2nd, and 29 Amphitrite (magnitude +9.2) on February 21st.  Finder charts for 18 Melpomene and 29 Amphitrite be found on page 49 of the February 2021 issue of Sky & Telescope.  Consult http://asteroidoccul.../2021_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/


Information on the celestial events transpiring each week can be found at http://astronomy.com/skythisweek and http://www.skyandtel...ky-at-a-glance/


An informative video discussing astronomical objects worthy of observing each month can be found at http://hubblesite.or...y/tonights_sky/


A monthly podcast on various astronomical topics is available at https://www.skyandte...onomy-podcasts/


Free star maps for the month can be downloaded at http://www.skymaps.com/downloads.html and http://www.telescope...thly-Star-Chart


An online interactive star chart appears at https://skyandtelesc...tive-sky-chart/


The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from 2.1 to 3.4, on February 1st, 4th, 7th, 10th, 12th, 15th, 18th, 21st, 24th, and 27th.  Consult page 50 of the February 2021 issue of Sky & Telescope for the times of the minima.  For more on Algol, see http://stars.astro.i.../sow/Algol.html and http://www.solstatio...ars2/algol3.htm


The Mira-type variable star R Virginis reaches it maxima of approximately sixth magnitude on February 24th.


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..._February-march


Telrad finder charts for the Messier Catalog and the SAC’s 110 Best of the NGC are posted at http://avila.star-sh...ssierTelrad.htm and http://www.custerobs...TIFdwMhiJElo8dY 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.


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