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 Mars and Saturn are at heliocentric conjunction (longitude 297.1 degrees) at 18:00
6/2 The Moon is 6.8 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 8:00
6/3 The Moon is at perigee, subtending 32' 48" from a distance of 364,366 kilometers (226,406 miles), at 3:38; Venus is at inferior conjunction with the Sun (0.289 astronomical units from the Earth and latitude 0.19 degrees) at 18:00
6/4 A double Galilean satellite shadow transit (Ganymede’s shadow precedes Europa’s) begins at 11:21; Mercury is at its greatest eastern elongation (24 degrees) at 13:00
6/5 The Moon is 6.3 degrees north-northeast of the first-magnitude star Antares (Alpha Scorpii) at 12:00; a penumbral lunar eclipse visible from Europe, Africa, Asia, and Australia begins at 17:45; Venus is at the descending node through the ecliptic plane at 19:00; Full Moon, known as the Rose or Strawberry Moon, occurs at 19:12
6/6 The Moon is at the descending node (longitude 269.1 degrees) at 18:00; Mars is at western quadrature (90 degrees from the Sun) at 19:00
6/8 The Moon is 2.2 degrees southeast of Jupiter at 19:00; the Moon, Jupiter, and Saturn lie within a circle with a diameter of 5.1 degrees at 22:00
6/9 The Moon is 2.7 degrees southeast of Saturn at 4:00
6/11 A double Galilean satellite shadow transit (Europa’s shadow precedes Ganymede’s) begins at 14:33
6/12 The equation of time, which yields the difference between mean solar time and apparent solar time, equals 0 at 15:00; Mercury is at the descending node through the ecliptic plane at 19:00; Venus is 4.2 degrees north-northwest of the first-magnitude star Aldebaran (Alpha Tauri) at 21:00
6/13 The earliest sunrise of the year at latitude 40 degrees north occurs today; the Moon, Mars, and Neptune lie within a circle with a diameter of 4.2 degrees at 2:00; the Moon is 2.5 degrees southeast of Mars at 3:00; the Moon is 4.2 degrees southeast of Neptune at 4:00; Last Quarter Moon occurs at 6:24; Mars (magnitude -0.2) is 1.6 degrees southeast of Neptune (magnitude +7.9) at 13:00
6/14 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to be visible at 15:02
6/15 The Moon is at apogee, subtending 29' 32" from a distance of 404,595 kilometers (251,404 miles), at 00:57
6/17 The earliest morning twilight of the year at latitude 40 degrees north occurs today; the Moon is 3.6 degrees southeast of Uranus at 5:00; Mercury is stationary, with retrograde (western) motion to begin, at 20:00
6/18 A double Galilean satellite shadow transit (Ganymede’s shadow precedes Europa’s) begins at 18:33; the Moon is 6.6 degrees southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 23:00
6/19 The Moon is 0.7 degrees north of Venus, with an occultation taking place in northern Mongolia, northern and central Russia, northwestern Europe, Greenland, northern and eastern Canada, the Canary Islands, and the Azores, at 9:00; the Moon, Venus, and Aldebaran lie within a circle with a diameter of 4.9 degrees at 11:00; the Moon is 3.7 degrees north of Aldebaran at 17:00
6/20 The middle of the eclipse season (i.e., the Sun is at same longitude as the Moon’s ascending node of 89.2 degrees) occurs at 1:00; Venus is 8.9 degrees southeast of M45 at 12:00; the northern hemisphere summer solstice occurs at 21:44; the Sun’s longitude is 90 degrees at 21:44
6/21 The Moon is at the ascending node (longitude 89.1 degrees) at 4:00; an annular solar eclipse visible from parts of Africa, Asia, and the western Pacific begins at 3:46; New Moon (lunation 1206) occurs at 6:41; the Sun enters the constellation of Gemini, at longitude 90.4 degrees on the ecliptic, at 9:00; the Moon is 0.7 degrees southeast of the bright open cluster M35 in Gemini at 11:00
6/22 The Moon is 3.9 degrees north of Mercury at 8:00; the Moon is 8.1 degrees south of the first-magnitude star Castor (Alpha Geminorum) at 22:00
6/23 The Moon is 4.5 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 2:00; Mercury is at aphelion (0.4667 astronomical units from the Sun) at 4:00; Neptune is stationary at 18:00
6/24 The latest evening twilight of the year at latitude 40 degrees north occurs today; the Moon is 2.0 degrees north-northeast of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 3:00; Venus is stationary, with prograde (eastern) motion to begin, at 18:00
6/25 The Moon is 4.2 degrees north-northeast of the first-magnitude star Regulus (Alpha Leonis) at 18:00
6/27 The latest sunset of the year at latitude 40 degrees north occurs today
6/28 The Purbach Cross or Lunar X, an X-shaped clair-obscure illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to be fully formed at 1:52; asteroid 7 Iris (magnitude +7.9) is at opposition at 2:00; First Quarter Moon occurs at 8:16
6/29 The Moon is 6.8 degrees north-northeast of Spica at 14:00
6/30 The Moon is at perigee, subtending 32' 23" from a distance of 368,958 kilometers (229,260 miles), at 2:13
Giovanni Cassini (1625-1712), John Dollond (1706-1761), Charles Messier (1730-1817), William Lassell (1799-1880), George Ellery Hale (1868-1938), and Carolyn Shoemaker (1929) were born this month.
The British astronomer Edmund Halley discovered M13 on June 1, 1714. 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. Neptune was independently discovered by the British astronomer John Couch Adams on June 5, 1846. The Italian astronomer Giovanni Battista Donati discovered Comet C/1858 L1 (Donati), the first comet to be photographed, on June 2, 1858. A large storm on Saturn was observed by the American astronomer E. E. Barnard. The Tunguska event occurred on June 30, 1908. The largest known solar flare was recorded on June 27, 1984. The Georgian astronomer Givi Kimeridze discovered a Type Ia supernova in the spiral galaxy M58 on June 28, 1989. Namaka, a satellite of the dwarf planet Haumea, was discovered on June 30, 2005. Kerberos, Pluto’s fourth satellite, was discovered by the Hubble Space Telescope team on June 28, 2011.
The minor Boötid meteor shower (5 per hour) peaks on the morning of June 27th. The source of Boötid meteors is the periodic comet 7P/Pons-Winnecke. The radiant lies in northern Boötes at right ascension 14 hours 56 minutes, declination 48 degrees. Browse https://in-the-sky.o...20200627_10_100 for additional information.
Information on passes of the ISS, the USAF’s X-37B, the HST, Starlink, and other satellites can be found at http://www.heavens-above.com/
The Moon is 9.1 days old, is illuminated 69.2%, subtends 32.9 arc minutes, and is located in Virgo on June 1st at 0:00 UT. The Moon is at its greatest northern declination of +24.1 degrees on June 22nd and at its greatest southern declination of -24.0 degrees on June 8th. Longitudinal libration is at a maximum of +5.9 degrees on June 9th and a minimum of -5.1 degrees on June 22nd. Latitudinal libration is at a maximum of +6.9 degrees on June 14th and a minimum of -6.7 degrees on June 1st and -6.8 degrees on June 28th. Favorable librations for the following craters occur on the indicated dates: Scott on June 3rd, Helmholtz on June 4th, Gibbs on June 6th, and Desargues on June 17th. A penumbral lunar eclipse, the 67th of 71 in saros series 111, is visible from Australia, the Indian Ocean, Antarctica, Asia, Africa, Europe, the southern Atlantic Ocean, eastern South America, and the western Pacific Ocean begins at 17:45:51 UT1, reaches greatest eclipse at 19:25:05 UT1, and ends at 21:04:09 UT1 on June 5th. Click on http://www.eclipsewi...c2020-Fig02.pdf for additional information on this eclipse. The Moon is at perigee (a distance of 57.13 Earth-radii) on June 3rd and (a distance of 57.85 Earth-radii) on June 30th and at apogee (a distance of 63.44 Earth-radii) on June 15th. New Moon occurs on June 21st. The Moon occults Venus on June 19th from certain parts of the world. Browse http://www.lunar-occ...ota/iotandx.htm for information on occultation events. Visit https://saberdoesthe...does-the-stars/ for tips on spotting extreme crescent Moons and http://www.curtrenz.com/moon06.html for Full Moon data. Consult http://time.unitariu...moon/where.html or download http://www.ap-i.net/avl/en/start for current information on the Moon. See https://svs.gsfc.nasa.gov/4768 for a lunar phase and libration calculator and https://svs.gsfc.nasa.gov/4768 for the Lunar Reconnaissance Orbiter Camera (LROC) Quickmap. Click on https://www.calendar...endar/2020/june for a lunar phase calendar for this month. Times and dates for the lunar crater light rays predicted to occur this month are available at http://www.lunar-occ.../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 20th. There are 15 hours and one minute of daylight at latitude 40 degrees north on June 20th, the day of the summer solstice. An annular solar eclipse takes place on June 21st. The eclipse, the 36th of 70 in saros series 137, is visible from Africa, eastern Europe, Asia, extreme northern Australia, the Indian Ocean, and the Pacific Ocean. Greatest eclipse occurs in Pakistan and northern India at 6:40:05 UT1. See http://www.eclipsewi...c2020-Fig03.pdf for more on this event. At latitude 40 degrees north, the earliest sunrise occurs on June 13th and the latest sunset on June 27th. For an explanation of why this occurs, click on https://earthsky.org/?p=4027
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on June 1st: Mercury (+0.1, 7.6", 45% illuminated, 0.89 a.u., Gemini), Venus (not visible, 57.6", 0% illuminated, 0.29 a.u., Taurus), Mars (magnitude 0.0, 9.3", 85% illuminated, 1.01 a.u., Aquarius), Jupiter (magnitude -2.6, 44.7", 100% illuminated, 4.41 a.u., Sagittarius), Saturn (magnitude +0.4, 17.8", 100% illuminated, 9.34 a.u., Capricornus), Uranus on June 16th (magnitude +5.9, 3.4", 100% illuminated, 20.49 a.u., Aries), Neptune on June 16th (magnitude +7.9, 2.3", 100% illuminated, 29.84 a.u., Aquarius), and Pluto on June 16th (magnitude +14.3, 0.1", 100% illuminated, 33.31 a.u., Sagittarius).
Mercury is in the west in the evening sky. Venus and Uranus can be found in the east, Mars and Neptune in the southeast, and Jupiter and Saturn can be found in the south in the morning sky.
The Moon, Jupiter, and Saturn lie within a circle with a diameter of 5.1 degrees on June 8th. On June 13th, the Moon, Mars, and Neptune lie within a circle with a diameter of 4.2 degrees. The Moon, Venus, and Aldebaran lie within a circle with a diameter of 4.9 degrees on June 19th.
Mercury increases in apparent size from 7.6 to 12.0 arc seconds but dims in brightness from magnitude +0.1 to +3.0. It attains a greatest eastern elongation of 24 degrees on June 4th. On that date, the speediest planet will shine at magnitude +0.4, subtend 8 arc seconds, will be illuminated 36%, and will set nearly two hours after sunset. By June 13th, it will be illuminated only 19%. Mercury will be visible in the evening sky until the middle of June.
Venus is at inferior conjunction on June 3rd. It will pass just 0.2 degrees from the Sun. Afterwards, Venus enters the morning sky. The 51-arc-second-in-diameter, 8%-illuminated planet will be occulted by a waning crescent Moon from certain parts of the world on the morning of June 19th. Venus lies near Melotte 25 (the Hyades) and is eight degrees in altitude one hour before sunrise on June 30th.
During June, Mars brightens from magnitude 0.0 to magnitude -0.5 and grows in apparent size from 9.3 to 11.4 arc seconds. Its altitude increases from 28 degrees on June 1st to 39 degrees on June 30th for mid-northern hemisphere observers. By month’s end, it rises not long after 12:30 a.m. DST. Mars and Saturn are at heliocentric conjunction on June 1st. Mars is at western quadrature on June 6th. As a result, the planet is illuminated only 84% and appears distinctly gibbous. On June 10th, Mars subtends 10 arc seconds, a bit less than one half of its maximum angular size at opposition on October 6th. The Last Quarter Moon passes 2.5 degrees southeast of Mars on June 13th. On June 24th, the Red Planet departs Aquarius and enters southern Pisces. Syrtis Major, a dark triangular region on the surface of Mars, will be visible by late June. An article on observing Mars appears on pages 48 and 49 of the June issue of Sky & Telescope. Consult the Mars Profiler at https://skyandtelesc...ide-is-visible/ to identify Martian surface features.
This month Saturn increases in brightness from magnitude +0.4 to magnitude +0.2 and in apparent size from 17.8 arc seconds to 18.3 arc seconds, while its rings span 41 arc seconds and are inclined more than 20 degrees. It rises about 15 minutes after Jupiter rises. Saturn and Mars are at heliocentric conjunction on June 1st. The waxing crescent Moon passes south of Saturn on June 9th. Eighth-magnitude Titan passes due north of Saturn on June 14th and June 30th and due south of the planet on June 6th and June 22nd. Iapetus shines at magnitude 10.9 when it is 10.2 arc minutes due west of the planet. This peculiar satellite is located 54 arc minutes north of Saturn when it reaches superior conjunction on June 20th. For information on Saturn’s satellites, browse http://www.skyandtel...tching-tools/
Uranus emerges from morning twilight but remains a difficult target. The waning crescent Moon passes five degrees south of Uranus on June 17th. A finder chart is available at http://www.nakedeyep...tm#finderchart
Neptune lies 3.5 degree east-northeast of the fourth-magnitude star Phi Aquarii this month and close to a sixth-magnitude field star. Mars passes less than two degrees southeast of Neptune on the morning of June 13th. The Last Quarter Moon passes four degrees south of Neptune on June 13th. Neptune reaches a stationary point on June 23rd. See http://www.nakedeyep...htm#finderchart for a finder chart.
Pluto lies four arc minutes south of HIP 97251, a ninth-magnitude field star, on June 1st. The dwarf planet is located 41.3 arc minutes due south of Jupiter by June 29th. A finder chart can be found at page 243 of the RASC Observer’s Handbook 2020.
Comet C/2017 T2 (PanSTARRS) travels southeastward through Ursa Major and Canes Venatici this month. It passes less than a degree to the west of the spiral galaxy M109 in Ursa Major on June 16th. On June 23rd, the comet is located less than a degree west of the spiral galaxy M106 in Canes Venatici. Comet PanSTARRS T2 passes less than one degree west of a third spiral galaxy, NGC 4449, on June 27th. Visit http://cometchasing.skyhound.com/ and http://www.aerith.ne...t/future-n.html for information on comets visible this month.
Shining at tenth magnitude, asteroid 2 Pallas glides northwestward through Vulpecula this month. It passes less than two degrees north of Collinder 399 (the Coathanger asterism) during the second week of June. Asteroid 7 Iris shines at magnitude +8.9 when it reaches opposition in Sagittarius on June 28th. Asteroids brighter than magnitude +11.0 that reach opposition this month include 85 Io (magnitude +8.9) on June 12th and 56 Melete (magnitude +10.6) on June 28th. Information on asteroid occultations taking place this month is available at http://www.asteroido.../2020_06_si.htm
An article on the June morning planets can be seen at https://drive.google...W_FTzEqVZ2/view
For more on the planets and how to locate them, browse http://www.nakedeyeplanets.com/
The Distance, Brightness, and Apparent Size of Planets graphic (Home / Sun & Moon / Planets / Distance, Brightness, and Apparent Size of Planets) at https://www.timeandd...lanets/distance displays the apparent and comparitive sizes of the planets, along with their magnitudes and distances, on a given date and time.
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.