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July 2014 Celestial Calendar

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#1 Dave Mitsky

Dave Mitsky

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Posted 30 June 2014 - 01:44 AM

July Celestial Calendar by Dave Mitsky

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

7/1 Mercury is stationary at 14:00
7/2 Venus is 4 degrees north of the first-magnitude star Aldebaran (Alpha Tauri) at 10:00
7/4 The Earth is at aphelion (a distance of 152,093,481 kilometers or 94,506,462 miles from the Sun) at 0:00; Pluto (magnitude +14.1, apparent size 0.1") is at opposition at 8:00; 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 occur at 17:13
7/5 First Quarter Moon occurs at 11:59
7/6 Mercury is at its greatest heliocentric latitude south today; Mars is 0.2 degree south of the Moon, with an occultation occurring in the northern half of South America, the west coast of Central America, and the Hawaiian Islands, at 1:00; asteroid 4 Vesta is 0.2 degree south of asteroid 1 Ceres at 9:00
7/8 Saturn is 0.4 degree north of the Moon, with an occultation occurring in the South Georgia and Sound Sandwich Islands, the southern tip of South America, and French Polynesia, at 2:00
7/12 Full Moon, known as the Hay or Thunder Moon, occurs at 11:25; Mercury is at greatest western elongation (21 degrees) at 18:00; Mars is 1.4 degrees north of the first-magnitude star Spica (Alpha Virginis) at 23:00
7/13 The Moon is at perigee, subtending 33 arc minutes from a distance of 358,260 kilometers (222,612 miles), at 20:00
7/15 Mercury is 3 degrees south of the bright open cluster M35 in Gemini at 9:00; Neptune is 5 degrees south of the Moon at 17:00
7/18 Uranus is 1.4 degrees south of the Moon at 10:00
7/19 Last Quarter Moon occurs at 2:08
7/20 Venus is 1.5 degrees south of M35 at 11:00; the Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to occur at 19:59
7/21 Saturn is stationary at 15:00
7/22 Uranus is stationary at 9:00; the Moon is 1.8 degrees north of the first-magnitude star Aldebaran (Alpha Tauri), at 12:00
7/24 Venus is 4 degrees north of the Moon at 18:00; Jupiter is in conjunction with the Sun at 21:00
7/25 Mercury is at the ascending node today; Mercury is 5 degrees north of the Moon at 15:00
7/26 New Moon (lunation 1133) occurs at 22:42
7/28 The Moon is at apogee, subtending 29 arc minutes from a distance of 406,567 kilometers (252,629 miles), at 3:00
7/29 Mercury is at perihelion today; the Southern Delta Aquarid meteor shower (15 per hour) peaks at 9:00

Friedrich Bessel was born this month. The first photograph of a star, namely Vega, was taken on July 17, 1850. The first photograph of a total solar eclipse was taken on July 28, 1851.

Moonlight will not interfere with the July 29th peak of this year’s Southern Delta Aquarid meteor shower. The other minor meteor showers with southern radiants occurring this month are the Alpha Capricornids, the Piscis Austrinids, and the Northern Delta Aquarids.

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

The Moon is 3.7 days old and is located in Cancer on July 1st at 0:00 UT. At that time, it is illuminated 12.1%. The Moon is at its greatest northern declination of +18.9 degrees on July 23rd and its greatest southern declination of -19.0 degrees on July 10th. Longitudinal libration is at a maximum of +7.3 degrees on July 19th and a minimum of -7.6 degrees on July 7th. Latitudinal libration is at a maximum of +6.6 degrees on July 26th and a minimum of -6.6 degrees on July 12th. Large tides will occur on July 12th through July 15th. The First Quarter Moon occults Mars from some locations in South America and the Pacific on the evening of July 5th. Saturn is occulted by the waxing gibbous Moon on the evening of July 7th for observers in other parts of the southern hemisphere. See http://www.lunar-occ...ota/iotandx.htm for information on these and other 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 in July are available at http://www.lunar-occ...o/rays/rays.htm

The Sun is located in Gemini on July 1st. The Earth is farthest from the Sun on July 4th, when it is 3.3% more distant than it was at perihelion and 1.7% farther than its average distance.

Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on July 1st: Mercury (+2.5 magnitude, 10.5", 11% illuminated, 0.64 a.u., Taurus), Venus (-3.9 magnitude, 12.0", 85% illuminated, 1.39 a.u., Taurus), Mars (0.0 magnitude, 9.5", 88% illuminated, 0.99 a.u., Virgo), Jupiter (-1.8 magnitude, 31.7", 100% illuminated, 6.22 a.u., Gemini), Saturn (+0.4 magnitude, 17.9", 100% illuminated, 9.26 a.u., Libra), Uranus (+5.8 magnitude, 3.5", 100% illuminated, 19.87 a.u. on July 16, Pisces), Neptune (+7.8 magnitude, 2.3", 100% illuminated, 29.23 a.u. on July 16, Aquarius), and Pluto (+14.1 magnitude, 0.1", 100% illuminated, 31.69 a.u. on July 16, Sagittarius).

Mars is located in the southwest, Jupiter in the northwest, and Saturn in the south during the evening. At midnight, Mars is in the west, Saturn is in the southwest, and Neptune in the southeast. In the morning, Mercury can be found in the northeast, Venus in the east, Uranus in the southeast, and Neptune in the south.

Mercury is at its greatest heliocentric latitude south on July 6th. It reaches greatest western elongation on July 12th. On July 15th, Mercury passes three degrees south of the bright open cluster M35 in Gemini. The speediest planet is at the ascending node on July 25th. It reaches perihelion on July 29th. By month’s end, Mercury shrinks to an angular diameter of 5.3 arc seconds but increases in illumination from 11 to 92% and brightens from magnitude +2.5 to magnitude -1.4.

As it pulls away from the Earth this month, Venus increases in illuminated extent from 85 to 92%, while its angular size decreases from 12.0 to 10.8 arc seconds. Its brightness drops slightly to magnitude -3.8, the dimmest the planet will be for 2014. Mercury and Venus are separated by less than seven degrees from July 12th to July 20th. An appulse takes place on July 16th, when Mercury lies just over six degrees to the east of Venus. Venus lies 1.5 degrees south of M35 on July 20th.

Mars fades from magnitude 0.0 to +0.4 and shrinks to 7.9 arc seconds in apparent size, as it heads eastward through Virgo this month. It reaches eastern quadrature on July 19th. As a result, the planet displays a somewhat gibbous phase during July.

Jupiter disappears into the glare of the Sun early this month. It reaches conjunction with the Sun on July 24th.

During July, Saturn’s rings span 40 arc seconds and are inclined by this year’s minimum angle of 21 degrees. The disk of the planet subtends 18 arc seconds at the equator. Saturn is stationary in right ascension on July 21st and afterwards resumes direct or eastward motion. Saturn’s odd satellite Iapetus lies to the west of the planet and shines at tenth magnitude early this month. For further information on Saturn’s satellites, browse http://www.skyandtel...watching-tools/

Uranus can be found about two degrees south of the fourth-magnitude star Epsilon Piscium. The seventh planet is stationary on July 22nd. It then begins to retrograde, moving westward with respect to the fixed stars, a change in apparent motion that results from the faster-moving Earth overtaking Uranus.

Neptune is located 1.9 degrees northeast of the fifth-magnitude star Sigma Aquarii at the start of the month. As July draws to a close, the eighth planet’s retrograde motion brings it to within 1.4 degrees of the star. Neptune rises about 90 minutes sooner than Uranus does this month.

Finder charts for Uranus and Neptune can be found at http://d366w3m5tf081...s_Neptune_20...

Pluto reaches opposition on July 4th. The dwarf planet lies within 30 arc minutes of the fifth-magnitude star 29 Sagittarii this month. A finder chart is available on pages 50 and 51 of the June issue of Sky & Telescope and at http://www.bluewater...2014_2_810K.jpg

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

By the middle of July, Comet C/2012 K1 (PanSTARRS) will be lost in evening twilight. The comet may reach seventh magnitude, as it heads southwestward through northwestern Leo in the vicinity of the fourth-magnitude star Mu Leonis and the third-magnitude star Epsilon Leonis. Browse http://cometchasing.skyhound.com/ and http://www.aerith.ne...t/future-n.html for additional information on comets visible in July.

Asteroids 1 Ceres (magnitude +8.4) and 4 Vesta (magnitude +7.1) are on a southeastward course through north-central Virgo this month. They are separated by only 19 arc minutes on the evening of July 1st. By July 4th, the gap between the two "minor planets" decreases to only ten arc minutes. For more on this historically significant event, see the article on pages 50 and 51 of the July issue of Sky & Telescope. Asteroid 611 Valeria will occult an 8.7-magnitude star in Pisces on the morning of July 19th. Consult http://www.skyandtel...the-printed-... for further information. Data on other asteroid occultations taking place this month is available at http://www.asteroido.../2014_07_si.htm

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

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

Forty binary and multiple stars for July: Eta Draconis, 17 & 16 Draconis, Mu Draconis, Struve 2273, Nu-1 & Nu-2 Draconis, Psi Draconis (Draco); Kappa Herculis, Gamma Herculis, Struve 2063, 56 Herculis, Struve 2120, Alpha Herculis (Ras Algethi), Delta Herculis, Rho Herculis, Mu Herculis (Hercules); Rho Ophiuchi, Lambda Ophiuchi, 36 Ophiuchi, Omicron Ophiuchi, Burnham 126 (ADS 10405), Struve 2166, 53 Ophiuchi, 61 Ophiuchi (Ophiuchus); h5003 (Sagittarius); Xi Scorpii, Struve 1999, Beta Scorpii, Nu Scorpii, 12 Scorpii, Sigma Scorpii, Alpha Scorpii (Antares), h4926 (Scorpius); Struve 2007, 49 Serpentis, Struve 2031 (Serpens Caput); 53 Serpentis, Struve 2204, h4995, h2814 (Serpens Cauda); Epsilon Ursae Minoris (Ursa Minor)

Notable carbon star for July: T Draconis

Sixty-five deep-sky objects for July: NGC 6140, NGC 6236, NGC 6340, NGC 6395, NGC 6412, NGC 6503, NGC 6543 (Draco); IC 4593, M13, M92, NGC 6106, NGC 6166, NGC 6173, NGC 6181, NGC 6207, NGC 6210, NGC 6229, NGC 6482 (Hercules); B61, B62, B63, B64, B72, IC 4634, IC 4665, LDN 42, LDN 1773, M9, M10, M12, M14, M19, M62, M107, NGC 6284, NGC 6287, NGC 6293, NGC 6304, NGC 6309, NGC 6356, NGC 6366, NGC 6369, NGC 6384, NGC 6401, Tr 26 (Ophiuchus); NGC 6440, NGC 6445 (Sagittarius); B50, B55, B56, Cr 316, M4, M6, M7, M80, NGC 6144, NGC 6153, NGC 6192, NGC 6231, NGC 6242, NGC 6302, NGC 6337, NGC 6451 (Scorpius); NGC 6217, NGC 6324 (Ursa Minor)

Top ten binocular deep-sky objects for July: IC 4665, LDN 1773, M4, M6, M7, M10, M12, M13, M92, NGC 6231

Top ten deep-sky objects for July: M4, M6, M7, M10, M12, M13, M92, NGC 6210, NGC 6231, NGC 6543

Challenge deep-sky object for July: NGC 6380 (Scorpius)

The objects listed above are located between 16:00 and 18:00 hours of right ascension.


 






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