February 2014 Celestial Calendar c/o Dave Mitsky

[Big Dipper]

February 2014 Celestial Calendar & Observing Notes c/o Dave Mitsky
(calendar data also reproduced in our forum calendar).

All times unless otherwise noted are UT.

2/1 Mercury is 4 degrees south of the Moon at 7:00; Neptune is 5 degrees south of the Moon at 14:00
2/2 The astronomical cross-quarter day known as Imbolc or Candlemas occurs today
2/3 Mercury is at perihelion today; Uranus is 3 degrees south of the Moon at 23:00
2/6 Mercury is stationary at 7:00; a double Galilean shadow transit (Europa’s shadow follows Callisto’s shadow) begins at 10:23; First Quarter Moon occurs at 19:22
2/7 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 occur at 6:32
2/11 Jupiter is 5 degrees north of the Moon at 6:00
2/12 The Moon is at apogee, subtending 29 arc minutes from a distance of 406,231 kilometers (252,420 miles), at 5:00
2/14 Mercury is at its greatest heliocentric latitude north today; Venus is at its greatest heliocentric latitude north today; Full Moon (known as the Hunger, Snow, or Storm Moon) occurs at 23:53
2/15 Venus is at its greatest illuminated extent at 9:00; Mercury is in inferior conjunction at 20:00
2/19 The Moon is 1.6 degrees north of the first-magnitude star Spica (Alpha Virginis) at 15:00
2/20 Mars is 3 degrees north of the Moon at 0:00
2/21 Saturn is 0.3 degree north of the Moon, with an occultation visible from New Zealand, most of Australia, and Madagascar, at 22:00
2/22 Asteroid 2 Pallas (magnitude 7.0) is at opposition at 9:00; Last Quarter Moon occurs at 17:15
2/23 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to occur at 7:47; Neptune is in conjunction with the Sun at 18:00
2/26 Venus is 0.4 degree north of the Moon, with an occultation visible from southeast Asia, India, and central and western Africa, at 5:00
2/27 The Moon is at perigee, subtending 33 arc minutes from a distance of 360,440 kilometers (223,967 miles), at 20:00; Mercury is 3 degrees south of the Moon at 21:00; Mercury is stationary at 23:00

Nicolas Copernicus (1473-1543), Galileo Galilei (1564-1642), and Clyde Tombaugh (1906-1997) were born this month.

Clyde Tombaugh discovered Pluto on February 18, 1930. Gerald Kuiper discovered the Uranian satellite Miranda (magnitude 15.8) on February 16, 1948.

The zodiacal light is visible in the western sky after sunset from dark locations in early February and during the latter part of the month.

Information on Iridium flares and passes of the ISS, the Tiangong-1, the USAF’s X-37B, the HST, and other satellites can be found at http://www.heavens-above.com/

The Moon is 1.1 days old and is located in the constellation of Capricornus at 0:00 UT on February 1st. The Moon is at its greatest northern declination of +19.3 degrees on February 9th and its greatest southern declination of -19.2 degrees on February 24th. Longitudinal libration is at a maximum of +7.7 degrees on February 5th and a minimum of -6.9 degrees on February 21st. Latitudinal libration is at a maximum of +6.6 degrees on February 12th and a minimum of -6.7 degrees on February 26th. Large tides occur on February 1st and February 2nd. The Moon is at apogee on February 12th and at perigee on February 27th. Mare Marginis and Mare Symthii are visible in the early part of the month, due to a favorable libration. Browse http://www.lunar-occultations.com/iota/ for information on upcoming lunar occultations. Visit http://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 http://www.lunar-occultations.com/rlo/rays/rays.htm

The Sun is located in the constellation of Capricornus on February 1st.

Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on February 1: Mercury (magnitude -0.6, 7.1", 51% illuminated, 0.94 a.u., Aquarius), Venus (magnitude –4.8, 51.1", 13% illuminated, 0.33 a.u., Sagittarius), Mars (magnitude +0.2, 8.9", 91% illuminated, 1.06 a.u., Virgo), Jupiter (magnitude -2.6, 45.6", 100% illuminated, 4.33 a.u., Gemini), Saturn (magnitude +0.5, 16.6", 100% illuminated, 10.02 a.u., Libra), Uranus (magnitude +5.9, 3.4", 100% illuminated, 20.73 a.u. on February 15th, Pisces), Neptune (magnitude +8.0, 2.2", 100% illuminated, 30.95 a.u. on February 15th, Aquarius), and Pluto (magnitude +14.2, 0.1", 100% illuminated, 33.31 a.u. on February 15th, Sagittarius).

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

Mercury can be seen eleven degrees above the west-southwestern horizon one half hour after the Sun sets on February 1st. At that time, it’s illuminated 51% and shines at magnitude -0.6 but will rapidly decline in brightness and altitude as the month progresses. Mercury passes four degrees south of the Moon on the same day. Perihelion takes place on February 3rd. The speediest planet is stationary on February 6th. It is at inferior conjunction on February 15th. Mercury reappears in the morning sky at month’s end and is positioned three degrees south of an extremely thin crescent Moon on the morning of February 27th.

Venus is at its greatest illuminated extent and greatest brilliancy (magnitude -4.9) on February 15th. The brilliant planet will cast a shadow at dark sites. An occultation of Venus by the waning crescent Moon is visible from some locations in the eastern hemisphere on February 26th. During February, the crescent-shaped planet’s illumination grows from 13 to 36% but its apparent size shrinks from 51 to 33 arc seconds.

At the start of the month, Mars rises around 11:00 p.m. local time. The Martian northern hemisphere summer solstice occurs on February 15th. Mars exceeds ten seconds in size on that date. On the evening of February 20th, Mars is 3 degrees north of the Moon. Mars increases in brightness from magnitude +0.2 to magnitude -0.4 and in apparent size from 8.9 to 11.5 arc seconds this month.

As Jupiter retrogrades slowly through Gemini this month, it drops to magnitude -2.4 and declines in apparent size to 42.6 arc seconds. The gas giant is at its greatest altitude around 10:00 p.m. local time, as the month begins. Noteworthy shadow transits by Io and Callisto respectively take place on the mornings of February 4th, beginning at 12:19 a.m. EST, and February 6th, beginning at 4:06 a.m. EST. On February 5th, Io reappears from eclipse at 11:56 p.m. EST. Jupiter is five degrees north of the Moon on the night of February 11th. Consult page 51 of the February 2014 issue of Sky & Telescope or browse http://skyandtelescope.com/observing/objects/planets/article_107_1.asp in order to determine transit times of Jupiter’s central meridian by the Great Red Spot. Data on the Galilean satellites is available at http://skytonight.com/observing/objects/javascript/3307071.html# and page 52 of the February 2014 issue of Sky & Telescope.

Saturn's rings span 39 arc seconds and are inclined 23 degrees from edge-on this month. As the month begins, Saturn rises around 1:30 a.m. local time. Saturn reaches western quadrature on February 11th. This means that the shadow of the planet’s globe on its rings is especially noticeable. An occultation of Saturn by the Moon is visible from some parts of the southern hemisphere on February 21st. Eight-magnitude Titan is north of Saturn on February 11th and February 27th and south of the planet on February 2nd/3rd and February 18th/19th. On February 16th, Iapetus is located 2.2 arc minutes due north of Saturn and shines at eleventh magnitude. For further information on the satellites of Saturn, browse http://www.skyandtelescope.com/observing/objects/javascript/3308506.html

Uranus is just 20 degrees above the western horizon at evening twilight by the middle of the month. It sets by mid-evening. Sir William Herschel’s discovery is located about five degrees southwest of the fourth-magnitude star Delta Piscium. A finder chart for Uranus can be found at http://media.skyandtelescope.com/documents/Uranus-Neptune-2013.pdf

Neptune is in conjunction with the Sun on February 23rd and is not visible this month.

The dwarf planet Pluto is not readily observable during February.

For more on the planets and how to locate them, browse http://www.nakedeyeplanets.com/

No comets brighter than tenth magnitude are predicted for this month. Visit http://cometchasing.skyhound.com/ and http://www.curtrenz.com/comets for additional information on comets visible in February.

Asteroids 1 Ceres (magnitude 8.2) and 4 Vesta (magnitude 7.2) are separated by 4.1 degrees on February 1st. Both objects are located south of the fourth-magnitude star Tau Virginis. A finder chart can be found on page 50 of the February 2014 issue of Sky & Telescope. Asteroid 2 Pallas lies to the southeast of the second-magnitude star Alphard (Alpha Hydrae) when it reaches opposition on February 22nd. It shines at magnitude 7.3 as February begins and at magnitude 7.6 as April begins. A finder chart appears on page 51 of the March 2014 issue of Sky & Telescope. The main-belt asteroid 532 Herculina shines at tenth magnitude as it travels first northwestward, then northeastward through Taurus this month. It passes between the third-magnitude star Zeta Tauri and M1 (the Crab Nebula) on February 5th.

A wealth of current information on solar system celestial bodies is posted at http://www.curtrenz.com/astronomical

Browse http://astrocast.tv/ for an informative video on astronomical events taking place this month

Free star maps for February can be downloaded at http://www.skymaps.com/downloads.html and http://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, 6th, 9th, 12th, 15th, 18th, 20th, 23rd, and 26th. Consult http://www.skyandtelescope.com/observing/objects/variablestars/Minima_of_Algo... for the times of the eclipses. For more on Algol, see http://stars.astro.illinois.edu/sow/Algol.html and http://www.solstation.com/stars2/algol3.htm

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.