You can download a PDF version of the Celestial Calendar here.
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 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 occur at 1:36; First Quarter Moon occurs at 12:42
6/2 A double Galilean satellite shadow transit occurs at 7:42
6/3 Venus (magnitude -4.3) is 1.7 degrees south-southeast of Uranus (magnitude +5.9) at 5:00; Venus is at greatest western elongation (45.9 degrees) at 12:00
6/4 Jupiter is 2.2 degrees south-southwest of the Moon at 1:00; a double Galilean satellite shadow transit occurs at 2:21; Venus is at theoretical dichotomy (50% illuminated) at 6:00; Neptune is at western quadrature at 16:00; the Moon is 6.3 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 22:00
6/5 A double Galilean satellite shadow transit occurs at 20:49
6/6 Asteroid 1 Ceres is in conjunction with the Sun at 0:00; Mars is at greatest declination north (24.3 degrees) at 7:00
6/7 Mercury is 5.5 degrees south-southeast of the bright open cluster M45 (the Pleiades or Subaru) at 8:00
6/8 Mars is 0.01 degree north-northwest of the bright open cluster M35 in Gemini at 1:00; the Moon is at apogee, subtending 29' 24" from a distance of 406,400 kilometers (252,526 miles), at 22:21
6/9 A double Galilean satellite shadow transit occurs at 10:09; Full Moon (known as the Flower, Rose or Strawberry Moon) occurs at 13:10
6/10 Saturn is 3.1 degrees south of the Moon at 2:00; Jupiter is stationary in right ascension at 4:00
6/11 Mercury is 4.9 degrees north-northwest of the first-magnitude star Aldebaran (Alpha Tauri) at 21:00
6/12 Pluto is 2.3 degrees south of the Moon at 2:00; Comet C/2015 V2 (Johnson) is at perihelion (1.637 astronomical units from the Sun) at 8:00; Venus is at aphelion (0.7282 astronomical units from the Sun) at 21:00; the equation of time - the difference between apparent time and mean time - is 0 at 22:00; a double Galilean satellite shadow transit occurs at 23:27
6/14 The earliest sunrise of the year at latitude 40 degrees north occurs today; Mercury is at the ascending node through the ecliptic plane at 21:00
6/15 The Moon is at the descending node (longitude 326.0 degrees) at 2:40; Saturn (angular size 18.4", magnitude 0.0) is at opposition at 10:00
6/16 A double Galilean satellite shadow transit occurs at 12:46; Neptune is 0.7 degree north-northwest of the Moon, with an occultation occurring in the southern half of South America and western Antarctica at 3:00; Neptune is stationary in right ascension at 23:00
6/17 The earliest morning twilight of the year at latitude 40 degrees north occurs today; Last Quarter Moon occurs at 11:34
6/18 The Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to occur at 0:40
6/19 Mercury is at perihelion (0.3075 astronomical units from the Sun) at 13:00; Uranus is 3.9 degrees north-northwest of the Moon at 18:00
6/20 A double Galilean satellite shadow transit occurs at 2:04; Venus is 2.3 degrees north-northwest of the Moon at 22:00
6/21 Summer solstice in the northern hemisphere occurs at 4:24; Mercury is in superior conjunction with the Sun at 14:00; the Sun enters Gemini (longitude 90.41 degrees on the ecliptic) at 15:00
6/22 The Moon is 0.54 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation taking place in northwestern Africa, most of Europe, the Azores, southern Greenland, and most of North America, at 15:00
6/23 The Moon is at perigee, subtending 33' 23" from a distance of 357,938 kilometers (222,412 miles), at 10:52; asteroid 40 Harmonia (magnitude +9.3) is at opposition at 11:00; a double Galilean satellite shadow transit occurs at 15:24
6/24 The latest evening twilight of the year at latitude 40 degrees north occurs today; New Moon (lunation 1169) occurs at 2:31; Mercury is at its greatest declination north (24.7 degrees) at 8:00; Mercury is 5.3 degrees north of the Moon at 9:00; Mars is 4.4 degrees north of the Moon at 20:00
6/25 The Moon is 9.4 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 13:00
6/26 The Moon is 2.8 degrees south of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 11:00
6/27 The latest sunset of the year at latitude 40 degrees north occurs today; the Moon is at the ascending node (longitude 145.2 degrees) at 16:27
6/28 The Moon is 0.04 degree southwest of the first-magnitude star Regulus (Alpha Leonis), with an occultation taking place in Ecuador, Peru, the Galapagos Islands, Hawaii, and Micronesia, at 1:00; Mercury is 0.77 degree north of Mars at 19:00
6/29 Mercury is at its greatest latitude north of the ecliptic plane (7.0 degrees) at 18:00
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. The French astronomer Charles Messier discovered M20 (the Trifid Nebula) on June 5, 1764. Charles Messier discovered the open cluster M23 on June 20, 1764. The French astronomer Pierre Méchain discovered the spiral galaxy M63 (the Sunflower Galaxy) on June 14, 1779. The Italian astronomer Giovanni Battista Donati discovered Comet C/1858 L1 (Donati), the first comet to be photographed, on June 2, 1858.
The usually minor June Boötid Class III meteor shower may peak on the morning of June 24th. June Boötids are the slowest of all meteors, travelling at 18 kilometers (11 miles) per second. Browse http://www.popastro.com/meteor/activity/activity.php?id_pag=485 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 6.2 days old, is illuminated 44.6%, subtends 31.7 arc minutes, and is located in Leo on June 1st at 0:00 UT. The Moon is at its greatest northern declination of +19.3 degrees on June 24th and at its greatest southern declination of -19.4 degrees on June 11th. Longitudinal libration is at a maximum of +7.5 degrees on June 1st and +7.4 degrees on June 29th and a minimum of -7.6 degrees on June 17th. Latitudinal libration is at a maximum of +6.6 degrees on June 22nd and a minimum of -6.6 degrees on June 8th. New Moon occurs on June 24th UT. Large tides will take place for several days thereafter. The First Quarter Moon occults the binary star Rho Leonis (magnitude +3.8) from most of the United States and Canada on the morning of June 1st. The Moon lies approximately three degrees to the upper left of the second-magnitude star Acrab (Beta Scorpii) at dusk on June 7th. From certain parts of the world, the Moon occults Neptune on June 16th, Aldebaran on June 22nd, and Regulus on June 28th. It also occults the third-magnitude star Gamma Leonis for much of North America on the night of June 30th (July 1st UT). See http://www.lunar-occultations.com/iota/iotandx.htm for information on lunar occultations taking place this month. 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 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 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 (-0.4, 6.3", 66% illuminated, 1.07 a.u., Aries), Venus (magnitude -4.5, 24.5", 48% illuminated, 0.68 a.u., Pisces), Mars (magnitude +1.7, 3.7", 99% illuminated, 2.53 a.u., Taurus), Jupiter (magnitude -2.2, 40.7", 99% illuminated, 4.84 a.u., Virgo), Saturn (magnitude +0.1, 18.3", 100% illuminated, 9.07 a.u., Ophiuchus), Uranus on June 16th (magnitude +5.9, 3.4", 100% illuminated, 20.45 a.u., Pisces), Neptune on June 16th (magnitude +7.9, 2.3", 100% illuminated, 29.74 a.u., Aquarius) and Pluto on June 16th (magnitude +14.2, 0.1", 100% illuminated, 32.42 a.u., Sagittarius).
Mars is in the northwest, Jupiter is in the southwest, and Saturn is in the southeast in the evening sky. At midnight, Jupiter lies in the southwest and Saturn lies in the south. Mercury, Venus, and Uranus can be found in the east, Saturn in the southwest, and Neptune in the southeast at dawn.
Mercury can be seen with difficulty prior to dawn in early June. On June 1st, it is four degrees above the east-northeastern horizon 30 minutes before the Sun rises. The speediest planet is at perihelion on June 19th and is in superior conjunction on June 21st.
Venus is at greatest western elongation on June 3rd. On that date, it rises two hours before sunup and is greater than ten degrees above the eastern horizon an hour before the Sun rises. Venus departs Pisces and enters Aries on June 10th. A waning crescent Moon passes close to the brightest planet on the mornings of June 20th and June 21st. Venus passes into Taurus on June 28th and is situated some eight degrees from the Pleiades on June 30th.
Mars moves into Gemini on June 5th. During the second week of June, the Red Planet disappears into the glare of the Sun.
Saturn reaches opposition on June 15th. At midmonth, the Ringed Planet shines at magnitude +0.0 and spans 18.4 arc seconds. Its rings subtend 41.7 arc seconds and are inclined by 27 degrees, the most since 2003. Eighth-magnitude Titan is positioned north of Saturn on June 8th and June 24th. At 11:30 p.m. EDT on the night of opposition, Titan lies to the south of the planet, Dione is to the west, and Tethys, Enceladus, and Rhea are to the east. For more on Saturn’s satellites, browse http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/
During June, Uranus is low in the east as twilight ends. It lies 2.4 degrees northeast of Venus on June 1st and 1.8 degrees north of Venus on June 2nd. Uranus remains within two degrees of Venus through June 4th. The ice giant planet rises earlier with each passing night and is located one degree northwest of the fourth-magnitude star Omicron Piscium on June 30th. Visit http://bluewaterastronomy.info/resources/uranus-finder-chart-2017.png for a finder chart.
By month’s end, Neptune is positioned in the southeast at an altitude of about 40 degrees as morning twilight begins. The eighth planet lies between the fourth-magnitude stars Lambda and Phi Aquarii, about 15 arc minutes east of the sixth-magnitude star 81 Aquarii. Browse http://bluewaterastronomy.info/resources/neptune-finder-chart-2017.png for a finder chart.
Pluto resides in northern Sagittarius. A finder chart appears on page 243 of the RASC Observer’s Handbook 2017.
For more on the planets and how to locate them, browse http://www.nakedeyeplanets.com/
Comet C/2015 V2 (Johnson) may shine at sixth magnitude as it heads southwestward through Boötes and into Virgo. It passes to the east of the first-magnitude star Arcturus on the nights of June 3rd and June 4th. The comet’s closest approach to the Earth occurs on June 5th. Comet Johnson is at perihelion on June 12th. Ninth-magnitude Comet 41P/Tuttle–Giacobini–Kresák travels southward through Ophiuchus near the constellation’s eastern border. Comet C/2015 ER61 (PanSTARRS) may reach seventh magnitude as it heads eastward through Pisces. Visit http://cometchasing.skyhound.com/ and http://www.aerith.net/comet/future-n.html for additional information on these and other comets visible during June.
Asteroid 12 Victoria glides northeastward through Virgo, remaining within 2.5 degrees of the first-magnitude star Spica (Alpha Virginis) for the entire month. The 112-kilometer-wide asteroid passes just southeast of the seventh-magnitude star 56 Virginis on the nights of June 7th and June 8th. During June, 12 Victoria decreases in brightness from magnitude +10.5 to magnitude +11.0. Asteroid 324 Bamberga (magnitude +10.3) is at opposition on June 23rd. Asteroid 10 Hygiea (magnitude +9.1) is at opposition on June 30th. Information on asteroid occultations taking place this month is available at http://www.asteroidoccultation.com/2017_06_si.htm
Free star maps for June can be downloaded at http://www.skymaps.com/downloads.html and http://www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
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/
An article on observing RR Lyrae variable stars, with maxima dates and times for VX Herculis, XZ Draconis, and XZ Cygni appears on pages 48-50 of the June 2017 issue of Sky & Telescope.
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.