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  • 02 May 2017 9:38 PM | Anonymous

    May Celestial Calendar by Dave Mitsky

     

    All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)

     

    5/1   May Day or Beltane, a cross-quarter day; Mars (heliocentric longitude 83.1 degrees) and Saturn (heliocentric longitude 263.1 degrees) are at heliocentric opposition at 7:00; the Moon is 9.7 degrees south of the first-magnitude star Pollux (Beta Geminorum)  at 18:00

    5/2   Mercury is stationary in right ascension at 14:00; the Moon is 3.3 degrees south of the bright open star cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 18:00

    5/3   First Quarter Moon occurs at 2:47; the Lunar X (also known as the Werner or Purbach Cross), an X-shaped illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to begin at 10:10

    5/4   The Moon is 0.51 degree north-northeast of the first-magnitude star Regulus (Alpha Leonis), with an occultation occurring in New Zealand, Australia, southern New Guinea, Malaysia, and Indonesia,  at 10:00; the Moon is at the ascending node (longitude 150.5°) at 10:44

    5/5   The Martian vernal equinox occurs at 12:00; Mars (magnitude +1.6) is 6.2 degrees north of the first-magnitude star Aldebaran (Alpha Tauri) at 22:00

    5/6   The peak of the Eta Aquarid meteor shower (20 per hour for northern hemisphere observers) occurs at 2:00; Mercury is at aphelion (0.4667 astronomical units from the Sun) at 14:00

    5/7   Jupiter is 2.0 degrees south of the Moon at 21:00; Mercury is 2.0 degrees south of Uranus at 23:00

    5/8   Asteroid 3 Juno is stationary in Aquila at 8:00

    5/9   Venus is at descending node at 7:00

    5/10 Full Moon, known as the Milk or Planting Moon, occurs at 21:43; Uranus (magnitude +5.9) is 0.65 degree south-southeast of the asteroid 20 Massalia (magnitude +11.7) at 22:00

    5 /12 A double Galilean satellite shadow transit begins at 1:59; the Moon is 9.5 degrees north of Antares at 13:00; the Moon is at apogee, subtending 29' 25'' from a distance of 406,210 kilometers (252,407 miles), at 23:51

    5/13 The equation of time equals 3.65 minutes at 22:00

    5/14 The Sun enters Taurus (ecliptic longitude 53.45 degrees) at 1:00

    5/15 A double Galilean satellite shadow transit begins at 14:56

    5/17 Mercury is at greatest western elongation (26 degrees) at 23:00

    5/19 Last Quarter Moon occurs at 0:34; a double Galilean satellite shadow transit begins at 3:54; the Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to be at a midpoint at 13:17

    5/20 Neptune is 0.46 degree north of the Moon, with an occultation occurring in the Maldives, Madagascar, southern Africa, and the Falkland Islands, at 6:00

    5/22 Venus is 2.3 degrees north-northwest of the Moon at 14:00; a double Galilean satellite shadow transit begins at 16:50

    5/23 Uranus is 3.7 degrees north-northwest of the Moon at 7:00; asteroid 8 Flora is 0.25 degree north of the Moon at 11:00

    5/24 Mercury is 1.5 degrees north-northwest of the Moon at 2:00

    5/25 New Moon (lunation 1168) occurs at 19:45

    5/26 The Moon is at perigee, subtending 33' 27'' from a distance of 357,210 kilometers (221,958 miles), at 1:21; a double Galilean satellite shadow transit begins at 5:47; Mercury is at its greatest latitude south of the ecliptic plane (-7.0 degrees) at 20:00

    5/27 Mars is 5.3 degrees north of the Moon at 3:00; the Moon is 5.0 degrees south of the bright open star cluster M35 in Gemini at 15:00

    5/28 A double Galilean satellite shadow transit begins at 0:16

    5/29 A double Galilean satellite shadow transit begins at 18:45

    5/30 The Moon is 3.0 degrees south of M44 at 1:00
    5/31 The Moon is at the ascending node (longitude 147.6 degrees) at 11:58; the Moon is 0.26 degree south of Regulus, with an occultation occurring in Mauritius, central and most of southern Africa, the Cape Verde Islands, and eastern Brazil, at 17:00

     

    Nicolas Lacaille (1713-1762), Joseph Lockyer (1836-1920), Williamina Fleming (1857-1911), and Frank Drake (1930) were born this month.

     

    The German astronomers Gottfried and Maria Magarethe Kirch discovered the bright globular cluster M5 on May 5, 1702.  On May 1, 1759, the English amateur astronomers John Bevis and Nicholas Munckley observed Comet Halley on its first predicted return.  The Italian astronomer Annibale de Gasparis discovered asteroid 14 Irene on May 19, 1851.  Asteroid 14 Irene was discovered on May 19, 1851 by the English astronomer John Russell Hind.  The German astronomer Robert Luther discovered asteroid 26 Proserpina on May 6, 1853.  The Australian astronomer John Tebbutt discovered the Great Comet of 1861 on May 13.  The English astronomer Norman Pogson discovered asteroid 80 Sappho on May 2, 1864.  Norman Pogson discovered asteroid 87 Sylvia on May 16, 1866.  The 40-inch Clark refractor at the Yerkes Observatory saw first light on May 21, 1897.  The Griffith Observatory opened to the public on May 14, 1935.  Nereid, Neptune’s third-largest satellite, was discovered on May 1, 1949 by the Dutch-American astronomer Gerard Kuiper. 

     

    The broad peak of the Eta Aquarid meteor shower centered on May 6th is compromised by a waxing gibbous Moon.  Southern hemisphere observers are favored.  The observing window for those living at 40 degrees north is 2.25 hours.  Eta Aquarid meteors are debris from the famous periodic comet 1P/Halley.  See http://www.imo.net/2017-eta-aquariids-predictions-and-observations/ for additional information.

     

    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 http://www.heavens-above.com/

     

    The Moon is 4.5 days old, is illuminated 27.0%, subtends 32.9 arc minutes, and is located in Gemini on May 1st at 0:00 UT.  The Moon is at its greatest northern declination on May 28th (+19.4 degrees).  The Moon is at its greatest its greatest southern declination on May 15th (-19.3 degrees).  Longitudinal libration is at maximum (+6.8 degrees) on May 4th and at minimum (-7.9 degrees) on May 20th.  Latitudinal libration is at maximum (+6.5 degrees) on May 25th and at minimum (-6.6 degrees) on May 12th.  New Moon occurs on May 25th.  The year’s shortest lunar month, lasting 29 days 6 hours and 46 minutes, begins on that day.  Large tides will take place for a few days after New Moon.  The Moon occults Regulus twice this month from certain parts of the world.  Consult http://www.lunar-occultations.com/iota/bstar/0504zc1487.htm and http://www.lunar-occultations.com/iota/bstar/0531zc1487.htm for more on these events.  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 Aries on May 1st.  It enters Taurus on May 14th.

     

    Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on May 1st: Mercury (magnitude +2.5, 11.2", 10% illuminated, 0.60 a.u., Pisces), Venus (magnitude -4.7, 37.8", 27% illuminated, 0.44 a.u., Pisces), Mars (magnitude +1.6, 3.9", 98% illuminated, 2.40 a.u., Taurus), Jupiter (magnitude -2.4, 43.5", 100% illuminated, 4.53 a.u., Virgo), Saturn (magnitude +0.3, 17.8", 100% illuminated, 9.34 a.u., Sagittarius), Uranus on May 16th (magnitude +5.9, 3.4", 100% illuminated, 20.80 a.u., Pisces), Neptune on May 16th (magnitude +7.9, 2.3", 100% illuminated, 30.26 a.u., Aquarius), and Pluto on May 16th (magnitude +14.2, 0.1", 100% illuminated, 32.72 a.u., Sagittarius).

     

    In the evening, Mars is in the northeast and Jupiter in the southeast.  Jupiter is located in the southwest and Saturn in the southeast at midnight.  Mercury and Venus can be seen in the east, Saturn in the southwest, Uranus in the east, and Neptune in the southeast at dawn.

     

    Mercury, Venus, and Uranus are all located in Pisces as May begins.

     

    Mercury is stationary on May 2nd, is at aphelion on May 6th, is at greatest western elongation on May 17th, and is at greatest heliocentric latitude south on May 26th.  The speediest planet will be low in the eastern sky prior to sunrise for northern hemisphere observers and will be more easily visible at the end of the month, when it brightens to magnitude -0.3.

     

    During May, Venus shines prominently in the dawn sky.  It decreases in angular diameter from 37.8 arc minutes to 24.8 arc minutes but increases in illumination from 27% to 48% during the course of the month.  As the sun rises in late May, Venus will reach an altitude of about 23 degrees for observers at 40 degrees north.  The brightest planet is at the descending node on May 9th.  On May 22nd, Venus lies 2.3 degrees north-northwest of the Moon in the morning sky.

     

    May is the last month of this year when Mars will be visible.  It subtends a mere three arc seconds and shines approximately one half-magnitude fainter than the class K5 giant star Aldebaran this month.  The Red Planet passes some six degrees north of Aldebaran between May 5th and May 7th and lies about the same distance to the upper right of a young crescent Moon on the evening of May 26th.

     

    Jupiter decreases in brightness from magnitude -2.4 to magnitude -2.3 and shrinks in angular diameter from 43.5 arc seconds to 40.8 arc seconds during May.  Jupiter culminates after 11:00 p.m. local daylight time on May 1st and just after 9:00 p.m. local daylight time on May 31st.  The largest gas giant continues to retrograde through Virgo, heading towards the binary star Porrima (Gamma Virginis).  On the night of May 9th/May 10th between 1:00 and 1:30 a.m. EDT, Ganymede, Io, and Callisto form a straight line at angle of approximately 40 degrees to the equator of the planet.  Earlier that night Ganymede exits from eclipse by Jupiter’s shadow at 10:55 p.m. EDT and Europa is occulted at 11:45 p.m. EDT.  In the early morning, Io begins to transit Jupiter at 2:47 a.m. EDT and its shadow follows at 3:30 a.m. EDT.  At 3:36 a.m. EDT, Europa emerges from eclipse.  Io’s transit ends at 4:58 a.m. EDT and its shadow departs Jupiter’s disk at 5:41 a.m. EDT, ending an eventful night of satellite events.  Double Galilean satellite shadow transits take place on May 12th, May 15th, May 19th, May 22nd, May 26th, May 28th, and May 29th.  The ones occurring on May 12th, May 19th, May 26th, and May 28th are of interest to observers in eastern North America.  Browse http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ or http://www.projectpluto.com/jeve_grs.htm in order to determine transit times of Jupiter’s central meridian by the Great Red Spot (GRS).  GRS transit information also appears on pages 50 and 51 of the May 2017 issue of Sky & Telescope.  Data on the Galilean satellite events is available on page 51 of the May 2017 issue of Sky & Telescope and online at http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and http://www.projectpluto.com/jevent.htm

     

    At mid-month, Saturn shines at magnitude +0.2 and has an apparent equatorial diameter of 18.1 arc seconds.  Its rings are inclined by 26 degrees and subtend 41 arc seconds.  In early May, Saturn transits the meridian at about 4:00 a.m.  It lies about five degrees to the west of M20 (the Trifid Nebula) and the open star cluster M21 and five degrees southwest of the open star cluster M23.  The Ringed Planet’s retrograde motion causes it to depart Sagittarius and enter Ophiuchus on May 18th.  Eighth-magnitude Titan is positioned north of the planet on May 7th and May 23rd and south of it on May 15th and May 31st.  Saturn’s variably bright moon Iapetus shines at tenth magnitude when it is located nine arc minutes from Saturn at greatest western elongation on May 9th.  As it passes two arc minutes north of Saturn on May 29th, Iapetus drops in brightness to eleventh magnitude, since its dark hemisphere is then facing Earthward.  For further information on Saturn’s satellites, browse http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ 

     

    Uranus is lost in morning twilight until late May.  On the morning of May 31st, Venus and Uranus are separated by about three degrees.

     

    Neptune passes nine arc minutes south of the sixth-magnitude star 81 Aquarii, which is located 2.2 degrees east-northeast of the fourth-magnitude star Lambda Aquarii, on May 14th.  Neptune lies within 20 arc minutes of 81 Aquarii for the entire month.

     

    Pluto lies in northern Sagittarius and transits the meridian before dawn.

     

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

     

    Comet 41P/Tuttle–Giacobini–Kresák heads southward through Hercules and Lyra in May.  The periodic comet passes very close to the fourth-magnitude star Kappa Lyrae on May 4th.  Comet C/2015 V2 (Johnson) slides southward through eastern Boötes.  Comet C/2015 ER61 (PanSTARRS) passes northwestward through Aquarius and Pisces this month.  Visit http://cometchasing.skyhound.com/ and http://www.aerith.net/comet/weekly/current.html for information on these and other comets visible this month.

     

    Asteroid 4 Vesta travels southeastward through Cancer this month.  The eighth-magnitude minor planet passes just north of the sixth-magnitude star Lambda Cancri on April 8th and April 9th, just south of the sixth-magnitude star Upsilon Cancri on April 16th, and a few degrees north of the bright open cluster M44 on April 21st.  Asteroids brighter than magnitude +11.0 that reach opposition this month include 30 Urania on May 6th, 52 Europa on May 12th, 196 Philomela on May 16th, and 27 Euterpe on May 25th.  Information on asteroid occultations taking place this month is available at http://www.asteroidoccultation.com/2017_05_si.htm

     

    A wealth of information on solar system celestial bodies is posted at http://nineplanets.org/

     

    A free star map for May 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 May 2nd, 5th, 8th, 11th, 14th, 17th, 20th, 22nd, 25th, 28th, and 31st.  For more on Algol, see http://stars.astro.illinois.edu/sow/Algol.html and http://www.solstation.com/stars2/algol3.htm

     

    Information pertaining to observing some of the more prominent Messier galaxies can be found at http://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 http://www.virtualcolony.com/sac/ and http://tonightssky.com/MainPage.php

     

    Eighty binary and multiple stars for May: 1 Bootis, Struve 1782, Tau Bootis, Struve 1785, Struve 1812 (Bootes); 2 Canum Venaticorum, Struve 1624, Struve 1632, Struve 1642, Struve 1645, 7 Canum Venaticorum, Alpha Canum Venaticorum (Cor Caroli), h2639, Struve 1723, 17 Canum Venaticorum, Otto Struve 261, Struve 1730, Struve 1555, h1234, 25 Canum Venaticorum, Struve 1769, Struve 1783, h1244 (Canes Venatici); 2 Comae Berenices, Struve 1615, Otto Struve 245, Struve 1633, 12 Comae Berenices, Struve 1639, 24 Comae Berenices, Otto Struve 253, Struve 1678, 30 Comae Berenices, Struve 1684, Struve 1685, 35 Comae Berenices, Burnham 112, h220, Struve 1722, Beta Comae Berenices, Burnham 800, Otto Struve 266, Struve 1748 (Coma Berenices); h4481, h4489, Struve 1604, Delta Corvi, Burnham 28, h1218, Struve 1669 (Corvus); H N 69, h4556 (Hydra); Otto Struve 244, Struve 1600, Struve 1695, Zeta Ursae Majoris (Mizar), Struve 1770, Struve 1795, Struve 1831 (Ursa Major); Struve 1616, Struve 1627, 17 Virginis, Struve 1648, Struve 1658, Struve 1677, Struve 1682, Struve 1689, Struve 1690, 44 Virginis, Struve 1719, Theta Virginis, 54 Virginis, Struve 1738, Struve 1740, Struve 1751, 81 Virginis, Struve 1764, Struve 1775, 84 Virginis, Struve 1788 (Virgo)

     

    Notable carbon star for May: SS Virginis

     

    One hundred and sixty-five deep-sky objects for May: NGC 5248 (Bootes); M3, M51, M63, M94, M106, NGC 4111, NGC 4138, NGC 4143, NGC 4151, NGC 4214, NGC 4217, NGC 4244, NGC 4346, NGC 4369, NGC 4449, NGC 4485, NGC 4490, NGC 4618, NGC 4631, NGC 4656, NGC 4868, NGC 5005, NGC 5033, NGC 5297, NGC 5353, NGC 5354, Up 1 (Canes Venatici); Mel 111, M53, M64, M85, M88, M91, M98, M99, M100, NGC 4064, NGC 4150, NGC 4203, NGC 4212, NGC 4251, NGC 4274, NGC 4278, NGC 4293, NGC 4298, NGC 4302, NGC 4314, NGC 4350, NGC 4414, NGC 4419, NGC 4448, NGC 4450, NGC 4459, NGC 4473, NGC 4474, NGC 4494, NGC 4559, NGC 4565, NGC 4651, NGC 4689, NGC 4710, NGC 4725, NGC 4874, NGC 5053 (Coma Berenices); NGC 4027, NGC 4038-9, NGC 4361 (Corvus); M68, M83, NGC 4105, NGC 4106, NGC 5061, NGC 5101, NGC 5135 (Hydra); M40, NGC 4036, NGC 4041, NGC 4051, NGC 4062, NGC 4085, NGC 4088, NGC 4096, NGC 4100, NGC 4144, NGC 4157, NGC 4605, NGC 5308, NGC 5322 (Ursa Major); M49, M58, M59, M60, M61, M84, M86, M87, M89, M90, M104, NGC 4030, NGC 4073, NGC 4168, NGC 4179, NGC 4206, NGC 4215, NGC 4216, NGC 4224, NGC 4235, NGC 4260, NGC 4261, NGC 4267, NGC 4281, NGC 4339, NGC 4343, NGC 4365, NGC 4371, NGC 4378, NGC 4380, NGC 4387, NGC 4388, NGC 4402, NGC 4429, NGC 4435, NGC 4438, NGC 4517, NGC 4526, NGC 4535, NGC 4536, NGC 4546, NGC 4550, NGC 4551, NGC 4567, NGC 4568, NGC 4570, NGC 4593, NGC 4596, NGC 4636, NGC 4638, NGC 4639, NGC 4643, NGC 4654, NGC 4666, NGC 4697, NGC 4698, NGC 4699, NGC 4753, NGC 4754, NGC 4760, NGC 4762, NGC 4866, NGC 4900, NGC 4958, NGC 5044, NGC 5054, NGC 5068, NGC 5077, NGC 5084, NGC 5087, NGC 5147, NGC 5170, NGC 5247, NGC 5363, NGC 5364 (Virgo)

     

    Top ten deep-sky objects for May: M3, M51, M63, M64, M83, M87, M104, M106, NGC 4449, NGC 4565

     

    Top ten deep-sky binocular objects for May: M3, M51, M63, M64, M84, M86, M87, M104, M106, Mel 111

     

    Challenge deep-sky object for May: 3C 273 (Virgo)

     

    The objects listed above are located between 12:00 and 14:00 hours of right ascension.

  • 20 Apr 2017 7:27 AM | Anonymous
    Join the International Dark-Sky Association for seven days of celebration, learning and action!

    Created in 2003 by high-school student Jennifer Barlow, International Dark Sky Week has grown to become a worldwide event and a key component of Global Astronomy Month. Each year it is held in April around Earth Day and Astronomy Day. This year celebrations begin Saturday, April 22 Earth Day!), and run through Friday, April 28 (click here for resources to use during the week).


    In explaining why she started the week, Barlow said, “I want people to be able to see the wonder of the night sky without the effects of light pollution. The universe is our view into our past and our vision into the future. … I want to help preserve its wonder.”


    International Dark Sky Week draws attention to the problems associated with light pollution and promotes simple solutions available to mitigate it. [Read More]

  • 06 Apr 2017 6:23 PM | Anonymous

    Astronomers have detected an atmosphere around the super-Earth GJ 1132b. This marks the first detection of an atmosphere around an Earth-like planet other than Earth itself, and thus a significant step on the path towards the detection of life on an exoplanet. The team, which includes researchers from the Max Planck Institute for Astronomy, used the 2.2 m ESO/MPG telescope in Chile to take images of the planet's host star GJ 1132, and measuring the slight decrease in brightness as the planet and its atmosphere absorbed some of the starlight while passing directly in front of their host star. Read More

  • 01 Apr 2017 9:21 AM | Anonymous

    All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)


    4/1   The Moon is 0.35 degree north-northwest of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation taking place in Japan, China, Mongolia, India, Saudi Arabia, and northeast Africa, at 9:00; Mercury is at greatest eastern elongation (19.0 degrees) at 10:00

    4/2   Mercury is at greatest heliocentric latitude north (7.0 degrees) at 19:00; the Moon is 5.4 degrees south of the bright open cluster M35 in Gemini at 23:00;

    4/3   First Quarter Moon occurs at 18:39;  the Lunar X (also known as the Werner or Purbach 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 22:21

    4/4   The Moon is 9.9 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 12:00

    4/5   The Moon is 3.5 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 12:00

    4/6   Saturn is stationary in right ascension at 5:00

    4/7   The Moon is 0.7 degree south-southwest of the first-magnitude star Regulus (Alpha Leonis), with an occultation taking place in far southern South America, the Antarctic Peninsula, and southern Polynesia, at 5:00; the Moon is at the ascending node (longitude 152.7 degrees) at 9:16; Jupiter (magnitude -2.5, 44.2" in apparent size) is at opposition at 22:00

    4/10 Mercury is stationary in right ascension at 1:00; Jupiter is 2.0 degrees south of the Moon at 21:00 

    4/11 Full Moon, known as the Egg or Grass Moon, occurs at6:08; the Moon is 6.1 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 10:00

    4/13 Venus is stationary in right ascension at 0:00; the periodic comet 41P/Tuttle-Giacobini-Kresák is at perihelion at 23:00

    4/14 Uranus is in conjunction with the Sun at 6:00

    4/15 The Moon 9.6 degrees north of Antares at 7:00; the equation of time equals zero at 10:00; the Moon is at apogee, subtending29' 28''from a distance of 405,474 kilometers(251,950 miles), at 10:05

    4/16 Saturn is 3.2 degrees south of the Moon at 19:00

    4/18 Pluto is 2.5 degrees south of the Moon at 14:00; the Sun enters the constellation of Aries at 22:00

    4/19 Last Quarter Moon occurs at 9:57

    4/20 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to begin at 1:27; Mercury is in inferior conjunction with the Sun at 6:00; Pluto is stationary in right ascension at 11:00; the periodic comet 103P/Hartley is at perihelion at 12:00

    4/21 Mars is 3.5 degrees south-southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 20:00; the Moon is at the descending node (longitude 331.5 degrees) at 22:32

    4/22 The peak of the Lyrid meteor shower (20 per hour) occurs at 12:00; Neptune is 0.21degrees northwest of the Moon, with an occultation taking place in central Polynesia, southeast Melanesia, New Zealand, and most of Australia, at 20:00

    4/23 Venus is 4.9 degrees north-northwest of the Moon at 21:00

    4/24 The Moon is 0.8 degree north of asteroid 2 Pallas, with an occultation taking place in Ireland, Iceland, Greenland, and most of North America, at 16:00 

    4/25 Uranus is 3.5 degrees north-northwest of the moon at 18:00;  Mercury is 4.3 degrees north-northeast of the Moon at 20:00; the Moon, Mercury, and Uranus all lie within a circle of diameter 4.3 degrees at 20:00

    4/26 Mercury is at the descending node through the ecliptic plane at 5:00; New Moon (lunation 1167) occurs at 12:17

    4/27 The Moon is at perigee, subtending33' 15''from a distance of 359,329 kilometers(223,275 miles), at 16:15

    4/28 The moon is 9.1 degrees south-southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 2:00; Comet C/2015 V2 (Johnson) is at opposition at 2:00; Mars is 5.7 degrees north of the moon at 9:00; Mercury (magnitude +3.0) is 0.09 degree southeast of Uranus (magnitude +5.9) at 12:00; the Moon is 0.49 degree north of Aldebaran, with an occultation taking place in northern Africa, Europe, far southern Greenland, eastern Canada, Cuba, and North America, at 18:00

    4/30 May Eve, a cross-quarter day; Venus is at greatest illuminated extent at 4:00; the Moon is 5.2 degrees south of the bright open cluster M35 in Gemini at 6:00



    Christiaan Huygens (1629-1695) was born this month.


    Johann Koehler discovered the elliptical galaxies M50 and M60 on April 11, 1779.  Caroline Herschel discovered C/1790 H1 (Herschel) on April 18, 1790.  The first photograph of the Sun was taken on April 2, 1845.  The first radar signal was bounced off of the Sun on April 7, 1959.  The Hubble Space Telescope was placed in orbit on April 25, 1990.  The Compton Gamma Ray Observatory achieved orbit on April 7, 1991.


    The Lyrid meteor shower peaks on the morning of April 22nd during a waning crescent Moon.  A typical zenithal hourly rate is about 20 meteors per hour but short outbursts have occurred occasionally.  The radiant lies between the Keystone of Hercules and Lyra.  For more on this year’s Lyrids, see http://earthsky.org/?p=158735 and http://www.skyandtelescope.com/astronomy-news/meteor-showers-in-2017/


    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 http://www.heavens-above.com/


    The Moon is 3.9 days old, is illuminated 20.0%, subtends 30.1', and is located in Taurus at 0:00 UT on April 1st.  The Moon is at its greatest northern declination of +18.9 degrees on April 3rd and +19.0 degrees on April 30th and its greatest southern declination of -19.0 degrees on April 18th.  Longitudinal libration is at a maximum of +5.6 degrees on April 6th and a minimum of -7.4 degrees on April 22nd.  Latitudinal librationis at a maximum of +6.7 degrees on April 1st and +6.6 degrees on April 28th and a minimum of -6.7 degrees on April 15th.  New Moon occurs on April 26th.  Very large tides occur for several days thereafter.  The Moon can be seen occulting Aldebaran from various parts of the world twice this month, on April 1st and April 28th.  Consult http://www.lunar-occultations.com/iota/bstar/bstar.htm for additional information on these events.  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 Pisces on April 1.  It enters Aries on April 18th.


    Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on April 1: Mercury (-0.2 magnitude, 7.5", 43% illuminated, 0.90 a.u., Pisces),Venus (-4.2, 57.9", 2% illuminated, 0.29 a.u., Pisces),Mars (+1.5 magnitude, 4.2", 96%illuminated, 2.23 a.u., Aries), Jupiter (-2.5 magnitude, 44.2", 100% illuminated, 4.46a.u., Virgo), Saturn (+0.4 magnitude, 17.0", 100% illuminated, 9.77a.u., Sagittarius), Uranus (+5.9 magnitude, 3.4", 100% illuminated, 20.93 a.u. on April 16th, Pisces), Neptune (+7.9 magnitude, 2.2", 100% illuminated, 30.68 a.u. on April 16th, Aquarius), and Pluto (+14.2 magnitude, 0.1", 100% illuminated, 33.16 a.u. on April 16th, Sagittarius). 


    Mercury and Mars are located in the west and Jupiter in the southeast in the evening.  At midnight, Jupiter is in the south.  Venus and Neptune can be found in the east, Jupiter in the west, and Saturn in the south in the morning sky.


    Mercury, Venus, Uranus, and the Sun are all located in Pisces on April 1st.


    Mercury is at greatest eastern elongation on April 1st, reaches its greatest latitude north of the ecliptic plane on April 2nd, and is stationary on April 10th.  It is in inferior conjunction on April 20th and is at the descending node through the ecliptic plane on April 26th.


    As April progresses, Venus grows increasingly more prominent in the morning sky.  On April 13th, it reaches its second stationary point in the Circlet of Pisces and thereafter resumes prograde motion.  The Moon passes five degrees north of Venus on April 23rd.  Venus decreases in apparent size from 57.9 to 38.5 arc seconds and increases in illumination from 2 to 26% over the course of the month.


    Mars sets shortly after 10:00 p.m. local daylight time this month.  It shrinks in apparent size to less than four arc seconds.  Mars departs Aries and enters Taurus on April 12th.  The Red Planet passes less than four degrees south of M45 (the Pleiades) on April 19th and April 20th and lies between the M45 and Melotte 25 (the Hyades) during the final week of April.


    Jupiter reaches opposition on April 7th.  Jupiter is two degrees south of the Moon on April 10th.  Jupiter shrinks in apparent diameter from 44.2 to 43.6 arc seconds and decreases in brightness from magnitude -2.5 to magnitude -2.4 during the course of the month.  On April 2nd, Io’s shadow falls on the planet at 11:31 p.m. EDTEight minutes later the satellite begins to transit Jupiter’s disk.  On April 9th, Io reappears from eclipse by Jupiter’s shadow at 6:18 a.m. EDT.  Io begins to transit the planet again at 1:22 a.m. EDT on April 10th, followed by its shadow three minutes later.  Europa is occulted by Jupiterat 3:52 a.m. EDT

    on April 14th.  Data on other Galilean satellite events is available at http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and page 51 of the April issue of Sky & Telescope.  For information on transits of Jupiter’s central meridian by the Great Red Spot, consult and page 50 of the April 2017 issue of Sky & Telescope.  


    As April begins, Saturn rises at approximately 1:30 a.m. local daylight time.  The planet rises around 11:30 p.m. local daylight time, brightens to magnitude +0.3, and subtends 17.8 arc seconds by the end of the month.  At mid-month, its rings span 39 arc seconds and are tilted more than 26 degrees with respect to the Earth.  Saturn is stationary in right ascension on April 6th and commences retrograde (western) motion thereafter.  It is situated within four degrees of the open clusters M21 and M23 and the nebulae M 8 (the Lagoon Nebula) and M20 (the Trifid Nebula) for the duration of the month.  The waning gibbous Moon passes three degrees north of the Ringed Planet on April 16th.  Titan, Saturn’s largest satellite, is north of the planet on April 6th and April 22nd and south of it on April 13th and April 29th.  For further information on Saturn’s satellites, browse http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ 

     

    Uranus is in conjunction with the Sun on April 14th and consequently is not visible this month.


    By the end of April, Neptune lies very low in the east at dawn.  Southern hemisphere observers have a more favorable view due to the angle of ecliptic.


    The dwarf planet Pluto is fairly high in the sky in northwestern Sagittarius during morning twilight.


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


    Asteroids 16 Psyche and 29 Amphitrite are located in southern Leo just this month.  The ninth- and tenth-magnitude asteroids are just northeast of Rho Leonis on April 1st and are less than one half of a degree apart.  A 9.5-magnitude star lies between the two asteroids.  Psyche heads northwestward and Amphitrite westward and then southeastward through Leo as April unfolds.  Asteroids brighter than magnitude +11.0 that reach opposition this month include 105 Artemis (magnitude +10.5) on April 3rd, 416 Vaticana (magnitude +10.9) on April 8th, 63 Ausonia (magnitude +10.1) on April 11th, 230 Athamantis (magnitude +10.6) on April 13th, and 12 Victoria (magnitude +9.8) on April 19th.  The thirteenth-magnitude asteroid 599 Luisa occults an 8.5-magnitude star in Scorpius for observers in certain parts of the Eastern Seaboard for as much as 11 seconds on the morning of April 10th.  The event is visible along a track extending from Maine to northern Florida.  The eleventh-magnitude asteroid 105 Artemis may occult an 8.9-magnitude star in Virgo for as much as 10 seconds on the morning of April 11th from parts of Arizona, Nevada, Utah, Idaho, Montana, and western Canada.  Click on http://www.asteroidoccultation.com/2017_04_si.htm for further information on these and other asteroid occultations taking place this month.  See http://www.curtrenz.com/asteroids.html for additional current information on asteroids.


    Comet 41P/Tuttle-Giacobini-Kresák may reach fifth magnitude this month as it passes through Draco and Hercules.  The periodic comet comes closest to the Earth on April 1st and reaches perihelion on April 13th.  Visit http://cometchasing.skyhound.com/ and http://www.aerith.net/comet/weekly/current.html for information on this month’s comets.


    A wealth of current information on solar system celestial bodies is posted at http://www.curtrenz.com/astronomy.html and http://nineplanets.org/

     

     

    A free star map for April can be downloaded at http://www.skymaps.com/downloads.html and http://www.telescope.com/content.jsp?pageName=Monthly-Star-Chart

     

    The fifth-magnitude G-type main-sequence star 61 Virginis - http://www.solstation.com/stars/61vir2co.jpg - is a sun-like star at a distance of 28 light years.  It hosts three exoplanets and is visible to the naked-eye.


    The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from 2.1 to 3.4, on April 1st, 4th, 7th, 9th, 12th, 15th, 18th, 21st, 24th, 27th, and 29th.  Consult http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ 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

     

    Information pertaining to observing some of the more prominent Messier galaxies can be found at http://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 http://www.virtualcolony.com/sac/ and http://tonightssky.com/MainPage.php

     

    Seventy-five binary and multiple stars for April: h4481 (Corvus); Aitken 1774, Gamma Crateris, Jacob 16, Struve 3072, h4456, Burnham 1078 (Crater); h4311, Burnham 219, N Hydrae, h4455, h4465 (Hydra); 31 Leonis, Alpha Leonis (Regulus), h2520, Struve 1417, 39 Leonis, Struve 1421, Gamma Leonis (Algieba), Otto Struve 216, 45 Leonis, Struve 1442, Struve 1447, 49 Leonis, Struve 1482, 54 Leonis, Struve 1506, Chi Leonis, 65 Leonis, Struve 1521, Struve 1527, Struve 1529, Iota Leonis, 81 Leonis, 83 Leonis, Tau Leonis, 88 Leonis, 90 Leonis, Struve 1565, Struve 1566, 93 Leonis, h1201, S Leonis (Leo); h2517, Struve 1405, Struve 1432, 33 Leo Minoris, Struve 1459, 40 Leo Minoris, Struve 1492 (Leo Minor); Struve 1401, Struve 1441, Struve 1456, Struve 1464, 35 Sextantis, 40 Sextantis, 41 Sextantis (Sextans); Struve 1402, Struve 1415, Struve 1427, Struve 1462, Struve 1486, Struve 1495, Struve 1510, Struve 1520, Xi Ursae Majoris, Nu Ursae Majoris, Struve 1541, 57 Ursae Majoris, Struve 1544, Struve 1553, Struve 1561, Struve 1563, 65 Ursae Majoris, Otto Struve 241 (Ursa Major).


    Notable carbon star for April: V Hydrae (Hydra)


    One hundred deep-sky objects for April: NGC 4024, NGC 4027 (Corvus); NGC 3511, NGC 3513, NGC 3672, NGC 3887, NGC 3892, NGC 3955, NGC 3962, NGC 3981 (Crater); NGC 3091, NGC 3109, NGC 3145, NGC 3203, NGC 3242, NGC 3309, NGC 3585, NGC 3621, NGC 3717, NGC 3904, NGC 3936 (Hydra); M65, M66, M95, M96, M105, NGC 3098, NGC 3162, NGC 3177, NGC 3185, NGC 3190, NGC 3226, NGC 3227, NGC 3300, NGC 3346, NGC 3367, NGC 3377, NGC 3384, NGC 3389, NGC 3412, NGC 3437, NGC 3489, NGC 3495, NGC 3507, NGC 3521, NGC 3593, NGC 3607, NGC 3608, NGC 3626, NGC 3628, NGC 3630, NGC 3640, NGC 3646, NGC 3655, NGC 3681, NGC 3684, NGC 3686, NGC 3691, NGC 3810, NGC 3842, NGC 3872, NGC 3900, NGC 4008 (Leo); NGC 3245, NGC 3254, NGC 3277, NGC 3294, NGC 3344, NGC 3414, NGC 3432, NGC 3486, NGC 3504 (Leo Minor); NGC 2990, NGC 3044, NGC 3055, NGC 3115, NGC 3156, NGC 3166, NGC 3169, NGC 3246, NGC 3423 (Sextans); IC 750, M97, M108, M109, NGC 3079, NGC 3184, NGC 3198, NGC 3310, NGC 3359, NGC 3610, NGC 3665, NGC 3675, NGC 3738, NGC 3877, NGC 3898, NGC 3941, NGC 3953, NGC 3998, NGC 4026 (Ursa Major).


    Top ten deep-sky objects for April: M65, M66, M95, M96, M97, M105, M108, NGC 3115, NGC 3242, NGC 3628

     

    Top ten binocular deep-sky objects for April: M65, M66, M95, M96, M97, M105, M108, M109, NGC 3115, NGC 3242

     

    Challenge deep-sky object for April: Leo I (Leo)

     

    The objects listed above are located between 10:00 and 12:00 hours of right ascension.



  • 12 Mar 2017 4:56 PM | Anonymous

    The A.L. last year instituted a progressive format for various levels of Master Observer. It was designed to guide observers through various programs, some required, others optional. As a result there are:

    1. Observer Award (minimum 5 programs)
    2. Master Observer Award (minimum 10 programs)
    3. Advanced Observer Award (minimum 15 programs)
    4. Master Observer Silver Award (minimum 20 programs)
    5. Master Observer Gold Award and (minimum 30 programs)
    6. Master Observer Platinum Award (minimum 40 programs)


    All are explained on their web site, esp. which programs are required and which to choose from for each level.


    For any members wishing guidance through the myriad of programs, this may be of help. Others may just choose whatever fancies them and not be bothered with too much structure. That's OK too.

  • 12 Mar 2017 4:26 PM | Anonymous

    March Celestial Calendar by Dave Mitsky


    All times, unless otherwise noted, are UT (subtract five hours and, when appropriate, one calendar day for EST and four hours for EDT as of March 12th)

    3/1   Venus is 9.7 degrees north-northwest of the Moon at 2:00; Uranus is 3.4 degrees north-northwest of the Moon at 18:00; the Moon, Mars, and Uranus lie within a circle with a diameter of 4.2 degrees at 20:00; Mars is 4.1 degrees north-northwest of the Moon at 21:00
    3/2   Neptune is in conjunction with the Sun at 3:00; Venus is stationary in right ascension at 14:00;   asteroid 1 Ceres is 0.8 degree north of the Moon, with an occultation visible from South Georgia, the Antarctic peninsula, and the southern half of South America, at 3:00
    3/3   The Moon is at perigee, subtending 32' 23" from a distance of 369,063 kilometers (229,325 miles), at 7:33; asteroid 29 Amphitrite (magnitude +9.1) is at opposition at 12:00
    3/4   The Moon is 9.3 degrees south-southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 10:00; Mercury is 1.0 degree south-southeast of Neptune at 12:00
    3/5   The 45%-illuminated Moon is 0.25 degree north-northwest of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation visible from the western Caribbean, Central America, most of the continental United States, Hawaii, Micronesia, and the Solomon Islands, at 3:00; 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 occur at 9:56; First Quarter Moon occurs at 11:32
    3/6   The Moon is 5.5 degrees south of the bright open cluster M35 in Gemini at 17:00
    3/7   Mercury is in superior conjunction with the Sun at 0:00; asteroid 4 Vesta is stationary at 3:00
    3/8   The Moon is 10.1 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 7:00; asteroid 41 Daphne (magnitude +9.6) is at opposition at 7:00
    3/9   The Moon is 3.6 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 7:00
    3/10 Comet 2P/Encke is at perihelion (0.3359 astronomical unit from the Sun) at 2:00; the Moon is 0.8 degrees south-southwest of the first-magnitude star Regulus (Alpha Leonis) at 22:00;
    3/11 The Moon is at the ascending node (longitude 153.4 degrees) at 4:20; the Sun enters Pisces, at longitude 351.6 degrees on the ecliptic, at 23:00
    3/12 Daylight Saving Time (DST) begins today; Full Moon (known as the Crow, Lenten, and Sap Moon) occurs at 14:54
    3/14 Venus is at its greatest latitude north of the ecliptic plane (3.4 degrees) at 6:00; Jupiter is 2.3 degrees south-southwest of the Moon at 22:00
    3/15 The Moon is 6.1 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 3:00; asteroid Pallas is in conjunction with the Sun at 3:00
    3/17 Saturn is at western quadrature (i.e., 90 degrees from the Sun) at 22:00
    3/18 The Moon is at apogee, subtending 29' 32" from a distance of 404,649 kilometers (251,438 miles), at 17:25; Mercury (magnitude -1.3) is 8.5 degrees south-southeast of Venus  (magnitude -4.2)  at 18:00; Mercury is at the ascending node at 22:00; the Moon is 9.8 degrees north of the first-magnitude star Antares (Alpha Scorpii) at 23:00
    3/20 Saturn is 3.4 degrees south of the Moon at 10:49; the vernal equinox occurs at 11:29; Last Quarter Moon occurs at 15:58
    3/21 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to be at a midpoint at 12:42
    3/25 Venus is in inferior conjunction with the Sun at 10:00; the Moon is at the descending node (longitude 333.1degrees) at 15:43
    3/26 Neptune is 0.01 degree east-northeast of the Moon, with an occultation visible from southwest Asia, Oman, Yemen, northern Madagascar, South Africa, and Ascension Island, at 8:00; Mercury (magnitude -0.8) is 2.1degrees north-northwest of Uranus (magnitude +5.9) at 10:00
    3/27 Venus is 10.7 degrees north-northwest of the Moon at 19:00
    3/28 New Moon (lunation 1166) occurs at 2:58
    3/29 Uranus is 3.4 degrees north-northwest of the Moon at 5:00; Mercury is 6.3 degrees north-northwest of the Moon at 11:00
    3/30 The Moon is at perigee, subtending 32' 50" from a distance of 363,854 kilometers (226,088 miles), at 12:32; Mars is 5.3 degrees north-northwest of the Moon at 16:00
    3/31 The Moon is 9.2 degrees south-southeast of M45 at 17:00 

    Nicolas-Louis de Lacaille (1713-), Caroline Herschel (1750-), Josef von Fraunhofer (1787-), John Herschel (1792-1871), Percival Lowell (1855-1916), Albert Einstein (1879-1955), and Walter Baade (1893-1960) were born this month.

    Titan, Saturn’s largest satellite, was discovered on March 25, 1655 by the Dutch astronomer Christiaan Huygens.  The English astronomer Edward Pigott discovered the spiral galaxy M63 (the Black Eye Galaxy) on March 23, 1779.  The English astronomer Sir William Herschel discovered Uranus on March 13, 1781.  Asteroid 4 Vesta was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on March 29, 1807.  The first photograph of the Moon was taken on March 23, 1840.  The Czech astronomer Luboš Kohoutek discovered Comet C/1973 E1 (Kohoutek) on March 7, 1973.  The rings of Uranus were discovered on March 10, 1977.  The Spanish amateur astronomer Francisco Garcia Diaz Garcia discovered supernova SN 1993 in the spiral galaxy M81 (Bode's Galaxy) on March 28th, 1993.

    The zodiacal light may be visible in the western sky after sunset from dark locations during the second half of March.

    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 http://www.heavens-above.com/

     
    The Moon is 2.4 days old, is illuminated 7.1%, subtends 32.3’, and is located in the constellation of Cetus at 0:00 UT on March 1st.  It's at its greatest northern declination of +18.9 degrees on March 7th and its greatest southern declination of -18.9 degrees on March 21st.  Longitudinal libration is at a maximum of +4.7 degrees on March 11th and a minimum of -6.4 degrees on March 25th.   Latitudinal libration is at a maximum of +6.8 degrees on March 5th and a minimum of -6.8 degrees on March 18th.  The Moon, Mars, and Uranus lie within a circle with a diameter of 4.2 degrees on March 1st.  New Moon occurs on March 28th.  The Moon will occult Aldebaran on March 4th (March 5th UT) for most of the Caribbean, Central America, and the continental United States.  A grazing occultation will take place in some portions of southern Canada, most of the states bordering Canada, and some of the northeastern states.  The Hyads θ1 and θ2 Tauri will also be occulted, as will some of the other bright stars in Melotte 20 (the Hyades).  Consult http://www.lunar-occ...bstar/bstar.htm and http://occultations....aran/2017march/ for information on these lunar occultation events.  Visit http://saberdoesthes...does-the-stars/ for tips on spotting extreme crescent Moons.  Click on http://www.calendar-...ndar/2017/march for a March lunar calendar.  Times and dates for the lunar light rays predicted to occur this month are available at http://www.lunar-occ...o/rays/rays.htm

    The Sun is in Aquarius on March 1st at 0:00 UT.  The Sun crosses the celestial equator at 10:29 on March 20th, bringing spring to the northern hemisphere. 

    Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on March 1st: Mercury (magnitude -1.3, 4.9", 99%, 1.38 a.u., Aquarius), Venus (magnitude -4.8, 46.9", 17% illuminated, 0.36 a.u., Pisces), Mars (magnitude +1.3, 4.6", 94% illuminated, 2.04 a.u., Pisces), Jupiter (magnitude -2.3, 42.1", 100% illuminated, 4.68 a.u., Virgo), Saturn (magnitude +0.5, 16.2", 100% illuminated, 10.28 a.u., Sagittarius), Uranus (magnitude +5.9, 3.4", 100% illuminated, 20.81 a.u. on March 16th, Pisces), Neptune (magnitude +8.0, 2.2", 100% illuminated, 30.92 a.u. on March 16th, Aquarius), and Pluto (magnitude +14.2, 0.1", 100% illuminated, 33.67 a.u. on March 16th, Sagittarius).

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

    Mercury is in superior conjunction on March 7th.  The speediest planet undergoes its best evening apparition of 2017 for observers at mid-northern latitudes during the second half of March.  It is at perihelion on March 23rd.  Mercury (magnitude -0.8) passes about two degrees to the right of Uranus (magnitude +5.9) on the evening of March 25th.

    Venus is stationary in central Pisces and begins retrograde motion on March 2nd.  It is at greatest heliocentric latitude north on March 14th.  Venus is eight degrees north of the Sun at inferior conjunction on March 25th, which makes the brightest planet observable during both morning and evening twilight for a period of a few days.

    Mars is located two degrees northeast of Uranus and four degrees northwest of the waxing crescent Moon on March 1st.  Mars exits Pisces and enters Aries on March 8th.

    Jupiter retrogrades through central Virgo this month but remains within four to six degrees of Spica.  The King of the Planets brightens from magnitude -2.3 to magnitude -2.5 and increases in apparent size by two arc seconds.  The Moon passes two degrees north of the planet on March 14th.  Shadow transits by Io take place on the mornings of March 2nd, March 9th, March 16th, and March 25th.  Europa’s shadow crosses Jupiter on the nights of March 15th/16th and March 22nd/23rd and on the morning of March 30th.  Shadow transits by Ganymede occur on the nights of March 9th/10th and March 16th/17th.  Callisto passes due south of Jupiter on the morning of March 13th.  Data on these and other Galilean satellite events is available online at http://www.shallowsky.com/jupiter/ and http://www.skyandtel...watching-tools/ and on page 51 of the March issue of Sky & Telescope.  Click on http://www.skyandtel...watching-tools/ or consult page 50 of the March issue of Sky & Telescope to determine transit times of the central meridian by the Great Red Spot.


    Saturn rises in western Sagittarius at approximately 2:30 a.m. local time on March 1st.  Saturn is located less than five degrees from M8 (the Lagoon Nebula), M20 (the Trifid Nebula), and the open cluster M23 for the entire month.  At mid-month, the planet’s disc spans 17 arc seconds at the equator, while its rings measure 38 arc seconds and are tilted by 26 degrees.  Saturn is at western quadrature on March 17th, a situation that enhances views of the shadows of the planet’s globe and rings.  The Last Quarter Moon passes threes degrees to the north of the Ringed Planet on the morning of March 20th.  Click on http://www.curtrenz.com/saturn for a wealth of information on Saturn.  For information on the major satellites of Saturn, browse http://www.skyandtel...watching-tools/

    Uranus is four degrees north of the Moon on March 1st.  The seventh planet disappears into evening twilight in late March.

    Neptune is in conjunction with the Sun on March 2nd and will not be visible again until April.

    A finder chart for Uranus appears on page 50 of the October 2016 issue and page 49 of the December 2016 issue of Sky & Telescope.  Online finder charts can be found at http://www.nakedeyep....com/uranus.htm.

    Click on http://www.skyandtel...watching-tools/ for JavaScript utilities that will illustrate the positions of the five brightest satellites of Uranus.

    See http://www.curtrenz.com/uranep.html for additional information on Uranus.

    Pluto is not a viable target this month.

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

    Comet 41P/Tuttle-Giacobini-Kresak may brighten to binocular visibility as it travels northeastward through Ursa Major this month.  The periodic comet is at perihelion on March 10th and passes within one degree north of the second-magnitude star Dubhe (Alpha Ursae Majoris) on the evening of March 27th.  Comet 41P will come closer to our planet in March than any time since 1858.   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 travels eastward through northern Gemini this month.  The main belt asteroid decreases in brightness from magnitude +7.1 to magnitude +7.6 during March.  It lies about one degree south of the fourth-magnitude star Upsilon Geminorum on March 27th.  Asteroids brighter than magnitude +11.0 coming to opposition this month include 29 Amphitrite (magnitude +9.1) on March 3rd, 16 Psyche (magnitude +10.3) on March 3rd , 41 Daphne (magnitude +9.6) on March 8th, and 409 Aspasia (magnitude +10.8) on March 29th.  The 15.2-magnitude asteroid 1343 Nicole occults HIP 46938, a 6.3-magnitude star located in western Leo less than one degree northeast of Lambda Leonis, for up to 3.4 seconds on the night of March 10th/11th.  A map of the occultation track and other information is available at http://asteroidoccul...3_52460_Map.gif and http://asteroidoccul...460_Summary.txt

    A wealth of current information on solar system celestial bodies is posted at http://nineplanets.org/

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


    The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from 2.1 to 3.4, on March 3rd, 6th, 9th, 12th, 15th, 17th, 20th, 23rd, 26th, and 29th.  Consult http://www.skyandtel...watching-tools/ for the times of the eclipses.  Favorable dates for observing Algol at mid-eclipse from the eastern United States include March 15th (12:24 a.m. EDT or 4:24 UT) and March 17th (9:14 p.m. EDT or 1:14 UT March 18th).  For more on Algol, see http://stars.astro.i.../sow/Algol.html.


    It is possible to observe all 109 (or 110) Messier objects during a single night around the time of the vernal equinox, if the Moon phase and local latitude are favorable.  For information on running a so-called Messier Marathon, browse http://messier.seds....n/marathon.html and http://www.richardbe...t/marathon.html

    Information pertaining to observing some of the more prominent Messier galaxies can be found at http://www.cloudynig...ur-astronomers/

    Thirty binary and multiple stars for March: Struve 1173, Struve 1181, Struve 1187, Zeta Cancri, 24 Cancri, Phi-2 Cancri, Iota-1 Cancri, Struve 1245, Iota-2 Cancri, 66 Cancri, Struve 1327 (Cancer); Struve 1270, Epsilon Hydrae, 15 Hydrae, 17 Hydrae, Theta Hydrae, 27 Hydrae, Struve 1347, Struve 1357, Struve 1365 (Hydra); 3 Leonis, Struve 1360, 6 Leonis, Omicron Leonis (Leo); Struve 1274, Struve 1282, Struve 1333, 38 Lyncis, Struve 1369 (Lynx); h4046 (Puppis)

    Notable carbon star for March: T Cancri (Cancer)

     
    Thirty-five deep-sky objects for March:
    M44, M67, NGC 2775 (Cancer); Abell 33, M48, NGC 2610, NGC 2642, NGC 2811, NGC 2835, NGC 2855, NGC 2935, NGC 2992, NGC 3052, NGC 3078 (Hydra); NGC 2903, NGC 2916, NGC 2964, NGC 2968, NGC 3020 (Leo); NGC 2859, NGC 3003, NGC 3021 (Leo Minor); NGC 2683 (Lynx); NGC 2567, NGC 2571 (Puppis); M81, M82, NGC 2639, NGC 2654, NGC 2681, NGC 2685, NGC 2742, NGC 2768, NGC 2787, NGC 2841, NGC 2880, NGC 2950, NGC 2976, NGC 2985 (Ursa Major)

     
    Top ten binocular deep-sky objects for March: M44, M48, M67, M81, M82, NGC 2571, NGC 2683, NGC 2841, NGC 2903, NGC 2976

    Top ten deep-sky objects for March: M44, M48, M67, M81, M82, NGC 2654, NGC 2683, NGC 2835, NGC 2841, NGC 2903


    Challenge deep-sky object for March: Abell 30 (Cancer)

    The objects listed above are located between 8:00 and 10:00 hours of right ascension.

  • 08 Mar 2017 12:21 PM | Anonymous

    This article originally appeared on the International Dark-Sky Association website January, 6 2017.


    Participating in dark sky activities gives kids first-hand, meaningful experiences that help them understand the obstacles we face in protecting our dark skies.  Creating fun opportunities engages and empowers the decision makers of tomorrow. Below is a list of ways you can enjoy dark skies with kids!read more...

  • 01 Mar 2017 10:27 PM | Anonymous

    Predicted Dates of Maxima and Minima of 381 Long Period Variables for 2017


    AAVSO Bulletin 80 - Predicted Dates of Maxima and Minima of Long Period Variables for 2017 - uses the same configurable format that was introduced with Bulletin 74 in 2011. Most of the information that was included in earlier numbers of the Bulletin is included in this new format, along with more information and links to external resources. Read more...

  • 13 Feb 2017 6:27 PM | Anonymous
    In the desert, the Earth boils and stars fill the sky. By day, you can see plumes of geothermal steam rising in every direction, pouring from vents in the ground and disappearing into the crisp, dry air. Read more...
  • 09 Feb 2017 9:23 PM | Anonymous

    It’s hard to comprehend the sheer size of objects in space , but let’s give it a try! This ESOcast takes a close look at the sizes of stars we see every night we’re out observing.

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