Post by Dave Mitsky on Feb 6, 2017 22:19:52 GMT
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 2.2 degrees north-northwest of the Moon at 3:00; Jupiter (magnitude +2.2) is 3.6 degrees north of the first-magnitude star Spica (magnitude +1.0) at 13:00
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; Uranus is 3 degrees north of the Moon at 8:00
2/3 Asteroid 1 Ceres (magnitude +8.9) is 1 degree south of the Moon in Pisces, with an occultation taking place in eastern Siberia, Alaska, northern Canada, and Greenland, at 2:00; 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 begin at 20:46
2/4 First Quarter Moon occurs at 4:19
2/5 The Moon is 9.3 degrees south-southeast of the bright open cluster M45 (the Pleiades or Subaru) at 5:00; the Moon is 0.2 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation taking place in the western portion of the Middle East, southern Europe, North Africa, the Caribbean, northern South America, and Central America, at 22:00
2/6 The Moon is at perigee, subtending 32' 24" from a distance of 368,816 kilometers (229,172 miles), at 14:02; Jupiter stationary in right ascension at 18:00
2/7 The Moon is 5.5 degrees south of the bright open cluster M35 in Gemini at 11:00; Mercury is at aphelion (0.4667 astronomical units from the Sun) at 14:00
2/9 The Moon is 10.0 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 0:00; the Moon is 3.6 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 23:00
2/11 Full Moon (known as the Hunger, Snow, or Storm Moon) occurs at 00:33; the moment of mid-eclipse of a deep penumbral lunar eclipse visible from the eastern Pacific Ocean, Asia, the Indian Ocean, Europe, Africa, the Middle East, the Atlantic Ocean, South America, and North America occurs at 0:44; the equation of time is at a minimum for the year (-14.24 minutes) at 4:00; the Moon is 0.8 degree south of the first-magnitude star Regulus (Alpha Leonis), with an occultation taking place in Australia, Wilkes Land, and New Zealand, at 14:00; the Moon is at the ascending node (ecliptic longitude 153.3 degrees) at 19:50
2/15 Jupiter is 2.7 degrees south of the Moon at 14:55
2/16 The Sun enters the constellation of Aquarius (ecliptic longitude 327.9 degrees) at 9:00
2/17 Jupiter at aphelion (5.4565 astronomical units from the Sun) at 4:00; Venus (magnitude -4.8) is at greatest brilliancy at 7:00
2/18 Asteroid 14 Irene (magnitude +8.5) is at opposition at 19:00; Last Quarter Moon occurs at 19:33; the Moon is at apogee, subtending 29' 33" from a distance of 404,376 kilometers (251,268 miles), at 21:14
2/19 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to begin at 23:01; the Moon is 9.8 degrees north of the first-magnitude star Antares (Alpha Scorpii) at 15:00
2/20 Asteroid 15 Eunomia (magnitude +8.9) is at opposition at 11:00; Venus is at perihelion (0.7184 astronomical units from the Sun) at 17:00
2/21 Saturn is 3.6 degrees south of the Moon at 0:00; the middle of the eclipse season (the Sun is at same ecliptic longitude as Moon’s descending node, 333.5 degrees) occurs at 22:00
2/22 Asteroid 9 Metis (magnitude +8.8) is at opposition at 2:00
2/23 Jupiter is 4.0 degrees north of Spica at 16:00
2/26 The Moon is at the descending node (ecliptic longitude 333.4 degrees) at 6:28; New Moon (lunation 1165) occurs at 14:58; the moment of greatest eclipse of an annular solar eclipse visible from southern Africa, the southern Atlantic Ocean, Argentina, Chile, and the southern Pacific Ocean, occurs at 14:54; Neptune is 0.14 degree south-southwest of the Moon at 21:00
2/27 Mars is at the ascending node at 5:00; Mars (magnitude +1.3) is 0.6 degree north of Uranus (magnitude +5.9) at 8:00; Mercury is at its greatest latitude south of the ecliptic plane (-7.0 degrees) at 21:00
2/28 Venus is 10 degrees north of Moon at 20:00
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.
Johann Bode discovered the globular cluster M53 in Coma Berenices on February 3, 1775. 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. Supernova 1987A was discovered by Ian Shelton, Oscar Duhalde, and Albert Jones on February 23, 1987. The first pulsar, PSR B1919+21, was discovered by Jocelyn Bell Burnell and Antony Hewish on February 24, 1967.
The zodiacal light should be visible in the west after evening twilight from a dark site beginning on February 13th.
Information on Iridium flares and passes of the ISS, the Tiangong-1, the Tiangong-2, the USAF’s X-37B, the HST, and other satellites can be found at www.heavens-above.com/
The Moon is 4.0 days old, is illuminated 17.3%, subtends 31.9', and is located in the constellation of Pisces at 0:00 UT on February 1st. A deep penumbral eclipse, number 59 of Saros 114, takes place on the evening of February 10th (February 11th UT). See eclipsewise.com/lunar/LEprime/2001-2100/LE2017Feb11Nprime.html or pages 48 and 49 of the February 2017 issue of Sky & Telescope for further information. The Moon is at apogee on February 18th and at perigee on February 6th. The Lunar X occurs on February 3rd and the Curtiss Cross on February 19th. New Moon occurs on February 26th. The synodic or lunar month beginning on January 28th and ending on February 26th is 29 days 14 hours and 51 minutes in length. The Moon occults 1Ceres on February 3rd, Aldebaran on February 5th, and Regulus on February 11th. Browse www.lunar-occultations.com/iota/ for information on this event and upcoming lunar occultations. Click on www.calendar-12.com/moon_calendar/2017/february for a February 2017 lunar calendar. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons. 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 the constellation of Capricornus on February 1st. It enters Aquarius on February 16th. An annular solar eclipse, number 29 in Saros 140, is visible from southern Africa, the southern Atlantic Ocean, Argentina, Chile, and the southern Pacific Ocean, on February 26th. Consult eclipsewise.com/solar/SEprime/2001-2100/SE2017Feb26Aprime.html for more on the eclipse.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on February 1: Mercury (magnitude -0.2, 5.6", 81% illuminated, 1.20 a.u., Sagittarius), Venus (magnitude -4.7, 30.8", 40% illuminated, 0.54 a.u., Pisces), Mars (magnitude +1.1, 5.1", 92% illuminated, 1.85 a.u., Pisces), Jupiter (magnitude -2.1, 39.0", 99% illuminated, 5.05 a.u., Virgo), Saturn (magnitude +0.5, 15.6", 100% illuminated, 10.69 a.u., Ophiuchus), Uranus (magnitude +5.9, 3.4", 100% illuminated, 20.49 a.u. on February 15th, Pisces), Neptune (magnitude +8.0, 2.2", 100% illuminated, 30.91 a.u. on February 15th, Aquarius), and Pluto (magnitude +14.2, 0.1", 100% illuminated, 34.03 a.u. on February 15th, Sagittarius).
Venus, Mars, and Neptune can be seen in the west and Uranus in the southwest in the evening sky. Jupiter is in the southeast at midnight. In the morning sky, Mercury and Saturn lie in the southeast and Jupiter in the southwest.
Mercury is present low in the morning sky for most of the month. It brightens from magnitude -0.2 to -1.2 while decreasing in apparent size from 5.6 to 4.9 arc seconds. Mercury is at aphelion on February 7th and is at greatest heliocentric latitude south on February 27th.
Venus becomes an increasingly larger crescent as it increases in apparent size by 15.4 arc seconds but decreases in illumination by 22% this month. On February 3rd, the brightest planet reaches a peak altitude of 40 degrees for observers at latitude 40 degrees north. Venus is at its greatest illuminated extent (i.e., maximum illuminated area in square arc seconds) on February 17th and is at perihelion on February 20th.
Mars decreases in apparent size from 5.1 to 4.6 arc seconds and dims to magnitude +1.3 during February. The Red Planet is in quasi-conjunction with Venus on February 1st. The two planets are separated by 5.4 degrees at the time. Mars (apparent size 4.6 arc seconds) is located within nine-tenths of a degree of Uranus (apparent size 3.4 arc seconds) from February 25th to February 27th.
Jupiter is stationary in right ascension and begins retrograde (westward) motion on February 6th. It is located 3.6 degrees due north of Spica on February 6th and 2.7 degrees south of the Moon on February 15th. Jupiter is at aphelion for the first time in 11.9 years on February 17th. Shadow transits by Io, Jupiter’s closest major satellite, take place starting at 1:53 a.m. EST (6:53 UT) on February 7th, 3:47 a.m. EST (8:47 UT) on February 14th, and at 5:40 a.m. EST (10:40 UT) on February 21st. Europa’s shadow will begin to cross Jupiter at 12:45 a.m. EST (5:45 UT) on February 19th and at 3:20 a.m. EST (8:20 UT) on February 26th Shadow transits by Ganymede take place on February 2nd beginning at 1:51 a.m. EST (6:51 UT) and on February 9th beginning at 5:49 a.m. EST (10:49 UT). 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 February 2017 issue of Sky & Telescope. Click on www.skyandtelescope.com/observing/interactive-sky-watching-tools/ or consult page 50 of the February 2017 issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot.
At mid-month, Saturn shines at magnitude +0.5. Its rings are inclined 27 degrees from edge-on and span 36 arc seconds. Saturn is 3.6 degrees south of the waning crescent Moon on the evening of February 20th. The Ringed Planet enters Sagittarius on February 23rd. It is situated less than four degrees from M20 (the Trifid Nebula) on February 28th. Saturn rises at approximately 2:30 a.m. local time by the end of February. For information on the satellites of Saturn, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
On February 1st, Uranus can be found in southeastern Pisces one degree east of the fifth-magnitude star Zeta Piscium. The seventh planet lies twice that distance from Zeta Piscium by the end of the month. Uranus is located three degrees south of the waxing Moon on February 2nd. On the evening of February 26th, Mars passes 34 arc minutes north of Uranus.
Neptune lies 1.2 degrees southwest of the fourth-magnitude star Lambda Aquarii. It disappears from view after the first week of February.
See www.curtrenz.com/uranep.html for additional information on the two outer planets.
Finder charts for Uranus and Neptune appear on page 50 of the October 2016 issue of Sky & Telescope. A finder chart for Uranus also appears on page 49 of the December 2016 issue of Sky & Telescope. Online finder charts for the two planets can be found at www.nakedeyeplanets.com/uranus.htm and www.nakedeyeplanets.com/neptune.htm and also at www.skyandtelescope.com/wp-content/uploads/WEB_UrNep16_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 not visible this month.
For more on the planets and how to locate them, browse www.nakedeyeplanets.com/
Comet 2P/Encke may brighten to seventh magnitude as it travels through Pisces this month. In the middle of February, the periodic comet lies less than one degree north of the fourth-magnitude star Omega Piscium. It then passes east and later south of that star. This will be the 63rd time Comet 2P/Encke has passed through the inner solar system since it was discovered to be a periodic comet in 1819. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html for additional information on Comet 2P/Encke and other comets visible this month.
During February, asteroid 4 Vesta travels northwestward through Gemini. The eighth-magnitude asteroid is located three degrees south of the first-magnitude star Pollux at the start of the month and four degrees southwest of that star as February ends. It lies about one half of a degree northwest of the fourth-magnitude star Kappa Geminorum on February 2nd and February 3rd. Asteroids brighter than magnitude +11.0 coming to opposition this month include 82 Alkmene on February 9th, 39 Laetitia on February 14th, 14 Irene on February 18th, 15 Eunomia on February 20th, and 9 Metis on February 22nd.
A wealth of current information on solar system celestial bodies is posted at www.curtrenz.com/astronomy.html and nineplanets.org/
Free star maps for February can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from 2.1 to 3.4, on February 3rd, 5th, 8th, 11th, 14th, 17th, 20th, 23rd, 25th, and 28th. Favorable dates for observing Algol at minimum brightness from the eastern United States include February 2nd (7:54 p.m. EST), February 19th (9:50 p.m. EST), and February 22nd (9:30 p.m. EST). Consult www.skyandtelescope.com/observing/interactive-sky-watching-tools/ or page 50 of the February 2017 issue of Sky & Telescope for the times of the eclipses. 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
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.
All times, unless otherwise noted, are UT (subtract five hours and, when appropriate, one calendar day for EST)
2/1 Mars is 2.2 degrees north-northwest of the Moon at 3:00; Jupiter (magnitude +2.2) is 3.6 degrees north of the first-magnitude star Spica (magnitude +1.0) at 13:00
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; Uranus is 3 degrees north of the Moon at 8:00
2/3 Asteroid 1 Ceres (magnitude +8.9) is 1 degree south of the Moon in Pisces, with an occultation taking place in eastern Siberia, Alaska, northern Canada, and Greenland, at 2:00; 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 begin at 20:46
2/4 First Quarter Moon occurs at 4:19
2/5 The Moon is 9.3 degrees south-southeast of the bright open cluster M45 (the Pleiades or Subaru) at 5:00; the Moon is 0.2 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation taking place in the western portion of the Middle East, southern Europe, North Africa, the Caribbean, northern South America, and Central America, at 22:00
2/6 The Moon is at perigee, subtending 32' 24" from a distance of 368,816 kilometers (229,172 miles), at 14:02; Jupiter stationary in right ascension at 18:00
2/7 The Moon is 5.5 degrees south of the bright open cluster M35 in Gemini at 11:00; Mercury is at aphelion (0.4667 astronomical units from the Sun) at 14:00
2/9 The Moon is 10.0 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 0:00; the Moon is 3.6 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 23:00
2/11 Full Moon (known as the Hunger, Snow, or Storm Moon) occurs at 00:33; the moment of mid-eclipse of a deep penumbral lunar eclipse visible from the eastern Pacific Ocean, Asia, the Indian Ocean, Europe, Africa, the Middle East, the Atlantic Ocean, South America, and North America occurs at 0:44; the equation of time is at a minimum for the year (-14.24 minutes) at 4:00; the Moon is 0.8 degree south of the first-magnitude star Regulus (Alpha Leonis), with an occultation taking place in Australia, Wilkes Land, and New Zealand, at 14:00; the Moon is at the ascending node (ecliptic longitude 153.3 degrees) at 19:50
2/15 Jupiter is 2.7 degrees south of the Moon at 14:55
2/16 The Sun enters the constellation of Aquarius (ecliptic longitude 327.9 degrees) at 9:00
2/17 Jupiter at aphelion (5.4565 astronomical units from the Sun) at 4:00; Venus (magnitude -4.8) is at greatest brilliancy at 7:00
2/18 Asteroid 14 Irene (magnitude +8.5) is at opposition at 19:00; Last Quarter Moon occurs at 19:33; the Moon is at apogee, subtending 29' 33" from a distance of 404,376 kilometers (251,268 miles), at 21:14
2/19 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to begin at 23:01; the Moon is 9.8 degrees north of the first-magnitude star Antares (Alpha Scorpii) at 15:00
2/20 Asteroid 15 Eunomia (magnitude +8.9) is at opposition at 11:00; Venus is at perihelion (0.7184 astronomical units from the Sun) at 17:00
2/21 Saturn is 3.6 degrees south of the Moon at 0:00; the middle of the eclipse season (the Sun is at same ecliptic longitude as Moon’s descending node, 333.5 degrees) occurs at 22:00
2/22 Asteroid 9 Metis (magnitude +8.8) is at opposition at 2:00
2/23 Jupiter is 4.0 degrees north of Spica at 16:00
2/26 The Moon is at the descending node (ecliptic longitude 333.4 degrees) at 6:28; New Moon (lunation 1165) occurs at 14:58; the moment of greatest eclipse of an annular solar eclipse visible from southern Africa, the southern Atlantic Ocean, Argentina, Chile, and the southern Pacific Ocean, occurs at 14:54; Neptune is 0.14 degree south-southwest of the Moon at 21:00
2/27 Mars is at the ascending node at 5:00; Mars (magnitude +1.3) is 0.6 degree north of Uranus (magnitude +5.9) at 8:00; Mercury is at its greatest latitude south of the ecliptic plane (-7.0 degrees) at 21:00
2/28 Venus is 10 degrees north of Moon at 20:00
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.
Johann Bode discovered the globular cluster M53 in Coma Berenices on February 3, 1775. 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. Supernova 1987A was discovered by Ian Shelton, Oscar Duhalde, and Albert Jones on February 23, 1987. The first pulsar, PSR B1919+21, was discovered by Jocelyn Bell Burnell and Antony Hewish on February 24, 1967.
The zodiacal light should be visible in the west after evening twilight from a dark site beginning on February 13th.
Information on Iridium flares and passes of the ISS, the Tiangong-1, the Tiangong-2, the USAF’s X-37B, the HST, and other satellites can be found at www.heavens-above.com/
The Moon is 4.0 days old, is illuminated 17.3%, subtends 31.9', and is located in the constellation of Pisces at 0:00 UT on February 1st. A deep penumbral eclipse, number 59 of Saros 114, takes place on the evening of February 10th (February 11th UT). See eclipsewise.com/lunar/LEprime/2001-2100/LE2017Feb11Nprime.html or pages 48 and 49 of the February 2017 issue of Sky & Telescope for further information. The Moon is at apogee on February 18th and at perigee on February 6th. The Lunar X occurs on February 3rd and the Curtiss Cross on February 19th. New Moon occurs on February 26th. The synodic or lunar month beginning on January 28th and ending on February 26th is 29 days 14 hours and 51 minutes in length. The Moon occults 1Ceres on February 3rd, Aldebaran on February 5th, and Regulus on February 11th. Browse www.lunar-occultations.com/iota/ for information on this event and upcoming lunar occultations. Click on www.calendar-12.com/moon_calendar/2017/february for a February 2017 lunar calendar. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons. 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 the constellation of Capricornus on February 1st. It enters Aquarius on February 16th. An annular solar eclipse, number 29 in Saros 140, is visible from southern Africa, the southern Atlantic Ocean, Argentina, Chile, and the southern Pacific Ocean, on February 26th. Consult eclipsewise.com/solar/SEprime/2001-2100/SE2017Feb26Aprime.html for more on the eclipse.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on February 1: Mercury (magnitude -0.2, 5.6", 81% illuminated, 1.20 a.u., Sagittarius), Venus (magnitude -4.7, 30.8", 40% illuminated, 0.54 a.u., Pisces), Mars (magnitude +1.1, 5.1", 92% illuminated, 1.85 a.u., Pisces), Jupiter (magnitude -2.1, 39.0", 99% illuminated, 5.05 a.u., Virgo), Saturn (magnitude +0.5, 15.6", 100% illuminated, 10.69 a.u., Ophiuchus), Uranus (magnitude +5.9, 3.4", 100% illuminated, 20.49 a.u. on February 15th, Pisces), Neptune (magnitude +8.0, 2.2", 100% illuminated, 30.91 a.u. on February 15th, Aquarius), and Pluto (magnitude +14.2, 0.1", 100% illuminated, 34.03 a.u. on February 15th, Sagittarius).
Venus, Mars, and Neptune can be seen in the west and Uranus in the southwest in the evening sky. Jupiter is in the southeast at midnight. In the morning sky, Mercury and Saturn lie in the southeast and Jupiter in the southwest.
Mercury is present low in the morning sky for most of the month. It brightens from magnitude -0.2 to -1.2 while decreasing in apparent size from 5.6 to 4.9 arc seconds. Mercury is at aphelion on February 7th and is at greatest heliocentric latitude south on February 27th.
Venus becomes an increasingly larger crescent as it increases in apparent size by 15.4 arc seconds but decreases in illumination by 22% this month. On February 3rd, the brightest planet reaches a peak altitude of 40 degrees for observers at latitude 40 degrees north. Venus is at its greatest illuminated extent (i.e., maximum illuminated area in square arc seconds) on February 17th and is at perihelion on February 20th.
Mars decreases in apparent size from 5.1 to 4.6 arc seconds and dims to magnitude +1.3 during February. The Red Planet is in quasi-conjunction with Venus on February 1st. The two planets are separated by 5.4 degrees at the time. Mars (apparent size 4.6 arc seconds) is located within nine-tenths of a degree of Uranus (apparent size 3.4 arc seconds) from February 25th to February 27th.
Jupiter is stationary in right ascension and begins retrograde (westward) motion on February 6th. It is located 3.6 degrees due north of Spica on February 6th and 2.7 degrees south of the Moon on February 15th. Jupiter is at aphelion for the first time in 11.9 years on February 17th. Shadow transits by Io, Jupiter’s closest major satellite, take place starting at 1:53 a.m. EST (6:53 UT) on February 7th, 3:47 a.m. EST (8:47 UT) on February 14th, and at 5:40 a.m. EST (10:40 UT) on February 21st. Europa’s shadow will begin to cross Jupiter at 12:45 a.m. EST (5:45 UT) on February 19th and at 3:20 a.m. EST (8:20 UT) on February 26th Shadow transits by Ganymede take place on February 2nd beginning at 1:51 a.m. EST (6:51 UT) and on February 9th beginning at 5:49 a.m. EST (10:49 UT). 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 February 2017 issue of Sky & Telescope. Click on www.skyandtelescope.com/observing/interactive-sky-watching-tools/ or consult page 50 of the February 2017 issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot.
At mid-month, Saturn shines at magnitude +0.5. Its rings are inclined 27 degrees from edge-on and span 36 arc seconds. Saturn is 3.6 degrees south of the waning crescent Moon on the evening of February 20th. The Ringed Planet enters Sagittarius on February 23rd. It is situated less than four degrees from M20 (the Trifid Nebula) on February 28th. Saturn rises at approximately 2:30 a.m. local time by the end of February. For information on the satellites of Saturn, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
On February 1st, Uranus can be found in southeastern Pisces one degree east of the fifth-magnitude star Zeta Piscium. The seventh planet lies twice that distance from Zeta Piscium by the end of the month. Uranus is located three degrees south of the waxing Moon on February 2nd. On the evening of February 26th, Mars passes 34 arc minutes north of Uranus.
Neptune lies 1.2 degrees southwest of the fourth-magnitude star Lambda Aquarii. It disappears from view after the first week of February.
See www.curtrenz.com/uranep.html for additional information on the two outer planets.
Finder charts for Uranus and Neptune appear on page 50 of the October 2016 issue of Sky & Telescope. A finder chart for Uranus also appears on page 49 of the December 2016 issue of Sky & Telescope. Online finder charts for the two planets can be found at www.nakedeyeplanets.com/uranus.htm and www.nakedeyeplanets.com/neptune.htm and also at www.skyandtelescope.com/wp-content/uploads/WEB_UrNep16_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 not visible this month.
For more on the planets and how to locate them, browse www.nakedeyeplanets.com/
Comet 2P/Encke may brighten to seventh magnitude as it travels through Pisces this month. In the middle of February, the periodic comet lies less than one degree north of the fourth-magnitude star Omega Piscium. It then passes east and later south of that star. This will be the 63rd time Comet 2P/Encke has passed through the inner solar system since it was discovered to be a periodic comet in 1819. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html for additional information on Comet 2P/Encke and other comets visible this month.
During February, asteroid 4 Vesta travels northwestward through Gemini. The eighth-magnitude asteroid is located three degrees south of the first-magnitude star Pollux at the start of the month and four degrees southwest of that star as February ends. It lies about one half of a degree northwest of the fourth-magnitude star Kappa Geminorum on February 2nd and February 3rd. Asteroids brighter than magnitude +11.0 coming to opposition this month include 82 Alkmene on February 9th, 39 Laetitia on February 14th, 14 Irene on February 18th, 15 Eunomia on February 20th, and 9 Metis on February 22nd.
A wealth of current information on solar system celestial bodies is posted at www.curtrenz.com/astronomy.html and nineplanets.org/
Free star maps for February can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from 2.1 to 3.4, on February 3rd, 5th, 8th, 11th, 14th, 17th, 20th, 23rd, 25th, and 28th. Favorable dates for observing Algol at minimum brightness from the eastern United States include February 2nd (7:54 p.m. EST), February 19th (9:50 p.m. EST), and February 22nd (9:30 p.m. EST). Consult www.skyandtelescope.com/observing/interactive-sky-watching-tools/ or page 50 of the February 2017 issue of Sky & Telescope for the times of the eclipses. 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
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.