June Celestial Calendar by Dave Mitsky
All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)
6/1 The Moon is 1.6 degrees north of Saturn at 1:00; Mercury is at the ascending node through the ecliptic plane at 18:00
6/2 The Moon is at apogee, subtending 29' 29" from a distance of 405,317 kilometers (251,852 miles), at 16:35
6/3 Mercury is 5.8 degrees north-northwest of the first-magnitude star Aldebaran (Alpha Tauri) at 11:00; the Moon is 3.1 degrees north of Mars at 11:00; the Moon is at the descending node (longitude 307.1degrees) at 12:37
6/5 Venus is 8.1 degrees south of the first-magnitude star Castor (Alpha Geminorum) at 21:00
6/6 Mercury is at superior conjunction with the Sun (1.322 astronomical units from the Earth) at 2:00; Mercury is at perihelion (0.3075 astronomical unit from the Sun) at 10:00; Venus is at its greatest latitude north of the ecliptic plane (3.4 degrees) at 15:00; Last Quarter Moon occurs at 18:32
6//7 The Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to be visible at 9:52
6/8 Venus is 4.7 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 9:00
6/9 Mars and Saturn are at heliocentric conjunction (heliocentric longitude 275.8 degrees) at 4:00
6/10 The Moon is 4.6 degrees south-southeast of Uranus at 6:00
6/12 The Moon is 8.8 degrees south-southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 8:00; the Moon is 1.2 degrees north of Aldebaran at 23:00
6/13 The equation of time, which is the difference between mean solar time and apparent solar time, is 0 at 4:00; New Moon (lunation 1181) occurs at 19:43; Mercury is 0.81degree north of the bright open cluster M35 in Gemini at 21:00
6/14 The earliest sunrise of the year at latitude 40 degrees north occurs today; the Moon is 3.8 degrees south of M35 at 11:00; the Moon is 4.6 degrees south of Mercury at 14:00; Mercury is at its greatest declination north (25.2 degrees) at 22:00; the Moon is at perigee, subtending 32' 14" from a distance of 359,503 kilometers (223,385 miles), at 23:53
6/15 Asteroid 29 Amphitrite (magnitude +9.5) is at opposition at 13:00
6/16 The Moon is 2.3 degrees south of Venus at 13:00; Mercury at its greatest latitude north of the ecliptic plane (7.0 degrees) at 15:00; the Moon is at the ascending node (longitude 126.5 degrees) at 17:52; the Moon is 1.2 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 20:00; asteroid 9 Metis (magnitude +9.7) is at opposition at 20:00
6/17 The earliest morning twilight of the year at latitude 40 degrees north occurs today
6/19 Neptune is stationary in right ascension, with retrograde (westward) motion to begin, at 9:00; asteroid 4 Vesta (magnitude +5.3) is at opposition at 10:00
6/20 Venus is 0.69 degree north-northeast of M44 at 10:00; the Purbach Cross or Lunar X, an X-shaped illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to be visible at 18:40
6/21 Sunrise takes place on the isolated lunar mountain Mons Pico at 3:19; summer solstice in the northern hemisphere occurs at 10:08; sunrise takes place on the isolated lunar mountain Mons Piton at 18:55; the Sun enters Gemini (longitude 90.43 degrees on the ecliptic) at 21:00
6/22 The Moon is 7.1 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 8:00
6/23 Mercury (magnitude -0.5) is 8.2 degrees south of the first-magnitude star Castor (Alpha Geminorum) at 7:00; the Moon is 4.0 degrees north-northeast of Jupiter at 21:00
6/24 The latest evening twilight of the year at latitude 40 degrees north occurs today
6/25 Mercury is 4.8 degrees south-southwest of the first-magnitude star Pollux (Beta Geminorum) at 1:00
6/26 The Moon is 8.9 degrees north of the first-magnitude star Antares (Alpha Scorpii) at 1:00; Mars is stationary in longitude at 21:00
6/27 The latest sunset of the year at latitude 40 degrees north occurs today; the Moon is 0.3 degree north of asteroid 4 Vesta, with an occultation taking place in the Galapagos Islands, Central America, southern Mexico, northern French Polynesia, Kiribati, and Micronesia, at 9:00; Saturn is at opposition (angular size 18.4", magnitude 0.0) at 13:00
6/28 The Moon is 1.8 degrees north of Saturn at 4:00; Full Moon (known as the Flower, Rose or Strawberry Moon) occurs at 4:53; Mars is stationary in right ascension, with retrograde (westward) motion to begin at 14:00
6/30 The Moon is at apogee, subtending 29' 26" from a distance of 406,061 kilometers (252,315 miles), at 2:43; the Moon is at the ascending node (longitude 306.0 degrees) at 16:45
Giovanni Cassini (1625-1712), Charles Messier (1730-1817), George Ellery Hale (1868-1938), and Carolyn Shoemaker (1929) were born this month.
The French astronomer Nicolas Louis de Lacaille discovered the globular cluster M55 on June 16, 1752. A transit of the Sun by Venus was observed by Austrian, British, and French astronomers from various parts of the world on June 6, 1761. The French astronomer Charles Messier discovered the globular cluster M14 on June 1st, 1764, the emission and reflection nebula M20 (the Trifid Nebula) on June 5, 1764, and the open cluster M23 on June 20, 1764. The globular cluster M62 was discovered by Charles Messier on June 7, 1771. The French astronomer Pierre Méchain discovered his first deep-sky object, the spiral galaxy M63 (the Sunflower Galaxy), on June 14, 1779. The German/English astronomer William Herschel discovered the globular cluster NGC 6288 on June 24, 1784. The Italian astronomer Giovanni Battista Donati discovered Comet C/1858 L1 (Donati), the first comet to be photographed, on June 2, 1858. The Tunguska event occurred on June 30, 1908. The Georgian astronomer Givi Kimeridze discovered a Type Ia supernova in the spiral galaxy M58 on June 28, 1989.
The minor Ophiuchid meteor shower (5 per hour) peaks on the morning of June 20th. Browse https://in-the-sky.o...20180620_10_100 for additional information.
Information on Iridium flares and passes of the ISS, 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 16.4 days old, is illuminated 95.4%, subtends 29.6 arc minutes, and is located in Leo on June 1st at 0:00 UT. The Moon is at its greatest northern declination of +20.7 degrees on June 15th and at its greatest southern declination of -20.7 degrees on June 1st. Longitudinal libration is at a maximum of +6.7 degrees on June 21st and a minimum of -7.4 degrees on June 9th. Latitudinal libration is at a maximum of +6.7 degrees on June 11th and a minimum of -6.7 degrees on June 23rd. New Moon occurs on June 13th. The shortest synodic month of the year starts with New Moon on June 13th and ends at New Moon on July 13th, lasting 29 days 7 hours and 5 minutes. The Moon is at apogee on June 2nd (distance 63.55 Earth-radii) and June 30th (distance 63.66 Earth-radii) and perigee on June 14th (distance 56.37 Earth-radii). The Moon occults asteroid 4 Vesta from certain parts of the world on June 27th. See http://www.lunar-occ...ota/iotandx.htm for information on lunar occultations taking place this month. Visit http://saberdoesthes...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-occ.../rays/rays.htm
The Sun is located in Taurus on June 1st. It enters Gemini on June 21st. The Sun reaches its farthest position north for the year on June 21st. There are 15 hours and one minute of daylight at latitude 40 degrees north on June 21st, the day of the summer solstice. At latitude 40 degrees north, the earliest sunrise occurs on June 14th and the latest sunset on June 27th.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on June 1st: Mercury (-1.7, 5.1", 97% illuminated, 1.31 a.u., Taurus), Venus (magnitude -3.9, 13.1", 80% illuminated, 1.27 a.u., Gemini), Mars (magnitude -1.2, 15.3", 91% illuminated, 0.61 a.u., Capricornus), Jupiter (magnitude -2.5, 44.1", 100% illuminated, 4.47 a.u., Libra), Saturn (magnitude +0.2, 18.2", 100% illuminated, 9.15 a.u., Sagittarius), Uranus on June 16th (magnitude +5.9, 3.4", 100% illuminated, 20.47 a.u., Aries), Neptune on June 16th (magnitude +7.9, 2.3", 100% illuminated, 29.78 a.u., Aquarius), and Pluto on June 16th (magnitude +14.2, 0.1", 100% illuminated, 32.66 a.u., Sagittarius).
Mercury is in the northwest, Venus is in the west, Jupiter is in the south, and Saturn is in the southeast in the evening sky. At midnight, Mars and Saturn lie in the southeast and Jupiter lies in the southwest. Mars can be found in the south, Saturn in the southwest, Uranus in the east, and Neptune in the southeast at dawn.
Mercury is at superior conjunction with the Sun on the night of June 5th/June 6th and is not visible again until mid-month. On June 14th, a very thin waxing crescent Moon and Mercury are nearly eight degrees apart very low in the west-northwest 30 minutes after sunset. Mercury is at its greatest heliocentric latitude north on June 16th. It sets 90 minutes after sunset by the end of the month.
Venus is easily visible at dusk for the entire month. It brightens from magnitude -3.9 to magnitude -4.1, increases in angular size from 13.1 arc seconds to 15.6 arc seconds, and decreases in illumination from 80% to 70%. Venus reaches its highest altitude at sunset (nearly 28 degrees for observers at latitude 40 degrees) for the year on June 6th. It enters Cancer on June 11th. The Moon passes two degrees south of the planet on June 16th. Venus passes through the far northern portion of M44 on the night of June 19th.
Mars rises around midnight as the month begins and around 10:30 p.m. local daylight time as June ends. During June, it brightens by almost a full magnitude, from magnitude -1.2 to magnitude -2.1, and grows in angular size from 15.3 arc seconds to 20.7 arc seconds. The waning gibbous Moon passes three degrees north of Mars on June 3rd. Two of the most prominent Martian surface features, the dark triangular region Syrtis Major and the bright Hellas basin, lie on the planet’s central meridian on the nights of June 6th through June 10th. The Red Planet ends its prograde (eastward) motion through Capricornus on June 28th.
Saturn rises not long after 10:00 p.m. local daylight time in early June. It is located 3.2 degrees south of the bright open cluster M25 and 1.9 degrees northwest of the bright globular cluster M22 on June 1st. The Ringed Planet’s retrograde motion carries it to a position approximately midway between M25 and the bright emission nebula M8 (the Lagoon Nebula) by June 31st. Saturn is visible for the entire night when it reaches opposition on June 27th. On that date, the planet shines at magnitude 0.0 and subtends 18.4 arc seconds at its equator, while its rings span 41.7 arc seconds and are inclined 25.7 degrees. The planet is located 22.5 degrees south of the celestial equator and is 75 light minutes (9.05 a.u.) from Earth at opposition. An article on Saturn at opposition appears on page 50 of the June 2018 issue of Sky & Telescope. The waning gibbous Moon passes less than two degrees north of Saturn on June 1st. On June 27th, the almost Full Moon passes less than two degrees from the planet. For information on Saturn’s satellites, browse http://www.skyandtel...atching-tools/
Uranus achieves an altitude of 20 degrees in the east as twilight ends in late June. The ice giant is situated in southwestern Aries, some twelve degrees south of the first-magnitude star Hamal (Alpha Arietis). Visit http://www.nakedeyep...htm#finderchart for a finder chart.
In early June, Neptune rises about 2:00 a.m. local daylight time. The eighth planet lies one degree west-southwest of the fourth-magnitude star Phi Aquarii. Browse http://www.nakedeyep...htm#finderchart for a finder chart.
Pluto resides in northeastern Sagittarius. A finder chart appears on page 48 and 49 of the July 2018 issue of Sky & Telescope and on page 243 of the RASC Observer’s Handbook 2018.
For more on the planets and how to locate them, browse http://www.nakedeyeplanets.com/
Comet C/2016 M1 (PanSTARRS) may shine at tenth magnitude as it travels southwestward through Sagittarius this month. It passes approximately 40 arc minutes from the eighth-magnitude globular cluster M54 on the nights of June 9th and June 10th and about twice that distance from the eighth-magnitude globular cluster M70 on the nights of June 12th and June 13th. Visit http://cometchasing.skyhound.com/ and http://www.aerith.ne...t/future-n.html for information on other comets visible this month.
Asteroid 4 Vesta (angular diameter 0.69", magnitude +5.3) reaches opposition in northwestern Sagittarius on June 19th. The brightest of all the asteroids travels southwestward through Sagittarius and into Ophiuchus this month. It passes south of the bright open cluster M23 in mid-June. A finder chart can be found on page 48 of the June 2018 issue of Sky & Telescope. Asteroid 4 Vesta should be visible without optical aid from a dark site. It will not be this bright again until 2031. The dwarf planet/asteroid 1 Ceres shines at ninth magnitude as it travels southeastward through Leo this month. It passes within 0.1 degree of the third-magnitude star Epsilon Leonis on June 3rd and the second-magnitude star Algieba (Gamma Leonis) on June 27th. Asteroid 29 Amphitrite (magnitude +9.5) is at opposition on June 15th and asteroid 9 Metis (magnitude +9.7) is at opposition on June 16th. Information on asteroid occultations taking place this month is available at http://www.asteroido.../2018_06_si.htm
Various events taking place within our solar system are discussed at http://www.bluewater...ed-4/index.html
Data on current supernovae can be found at http://www.rochester...y.org/snimages/
Information pertaining to observing some of the more prominent Messier galaxies can be found at http://www.cloudynig...ur-astronomers/
Forty binary and multiple stars for June: Struve 1812, Kappa Bootis, Otto Struve 279, Iota Bootis, Struve 1825, Struve 1835, Pi Bootis, Epsilon Bootis, Struve 1889, 39 Bootis, Xi Bootis, Struve 1910, Delta Bootis, Mu Bootis (Bootes); Struve 1803 (Canes Venatici); Struve 1932, Struve 1964, Zeta Coronae Borealis, Struve 1973, Otto Struve 302 (Corona Borealis); Struve 1927, Struve 1984, Struve 2054, Eta Draconis, 17-16 Draconis, 17 Draconis (Draco); 54 Hydrae (Hydra); Struve 1919, 5 Serpentis, 6 Serpentis, Struve 1950, Delta Serpentis, Otto Struve 300, Beta Serpentis, Struve 1985 (Serpens Caput); Struve 1831 (Ursa Major); Pi-1 Ursae Minoris (Ursa Minor); Struve 1802, Struve 1833, Phi Virginis (Virgo)
Notable carbon star for June: V Coronae Borealis
Fifty deep-sky objects for June: NGC 5466, NGC 5676, NGC 5689 (Bootes); M102 (NGC 5866), NGC 5678, NGC 5879, NGC 5905, NGC 5907, NGC 5908, NGC 5949, NGC 5963, NGC 5965, NGC 5982, NGC 5985, NGC 6015 (Draco); NGC 5694 (Hydra); NGC 5728, NGC 5791, NGC 5796, NGC 5812, NGC 5861, NGC 5878, NGC 5897 (Libra); M5, NGC 5921, NGC 5957, NGC 5962, NGC 5970, NGC 5984 (Serpens Caput); M101, NGC 5473, NGC 5474, NGC 5485, NGC 5585, NGC 5631 (Ursa Major); NGC 5566, NGC 5634, NGC 5701, NGC 5713, NGC 5746, NGC 5750, NGC 5775, NGC 5806, NGC 5813, NGC 5831, NGC 5838, NGC 5846, NGC 5850, NGC 5854, NGC 5864 (Virgo)
Top ten deep-sky objects for June: M5, M101, M102, NGC 5566, NGC 5585, NGC 5689, NGC 5746, NGC 5813, NGC 5838, NGC 5907
Top five deep-sky binocular objects for June: M5, M101, M102, NGC 5466, NGC 5907
Challenge deep-sky object for June: Abell 2065
The objects listed above are located between 14:00 and 16:00 hours of right ascension.