Post by Dave Mitsky on Sept 5, 2015 2:25:25 GMT
September Celestial Calendar by Dave Mitsky
All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)
9/1 Neptune (magnitude +7.8, apparent size 2.4") is at opposition at 4:00; Uranus is 1.1 degrees north of the Moon, with an occultation taking place in most of New Zealand and parts of Antarctica, at 16:00
9/4 Mercury is at its greatest eastern elongation (27 degrees) at 10:00
9/5 The Moon is 0.5 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation taking place in northwestern Asia, western Russia, Europe, and eastern North America, at 6:00; Last Quarter Moon occurs at 9:54; Venus is stationary at 9:00
9/6 Asteroid Metis (magnitude +8.8) is at opposition at 3:00
9/7 The Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to occur at 3:50
9/10 Venus is 3 degrees south of the Moon at 6:00; Mars is 5 degrees north of the Moon at 23:00
9/13 A partial solar eclipse visible from southern Africa, the southern Indian Ocean, and Antarctica begins at 4:41; New Moon (lunation 1147) occurs at 6:41
9/14 The Moon is at apogee, subtending 29' 20" from a distance of 406,464 kilometers (252,565 miles), at 11:00
9/15 Mercury is 5 degrees south of the Moon at 6:00; asteroid 1 Ceres is stationary at 18:00
9/17 Mercury is stationary at 13:00
9/19 Mercury is at its greatest heliocentric latitude south today; Saturn is 3 degrees south of the Moon at 3:00
9/20 The Lunar X (the Purbach or Werner Cross), an X-shaped illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to occur at 13:56
9/21 First Quarter Moon occurs at 8:59
9/23 The autumnal equinox occurs in the northern hemisphere at 8:21
9/24 Mars is 0.8 degree north of the first-magnitude star Regulus (Alpha Leonis) at 17:00; Pluto is stationary at 19:00
9/26 Neptune is 3 degrees south of the Moon at 10:00
9/28 The Moon is at perigee, subtending 33' 50" from a distance of 356,877 kilometers (221,753 miles), at 2:00; a total lunar eclipse begins at 2:11 and ends at 3:23; Full Moon (known as the Barley, Corn, or Fruit Moon), the largest of 2015 and this year’s Harvest Moon, occurs at 2:51
9/29 Uranus is 1.0 degree north of the Moon, with an occultation taking place in the southern portion of Madagascar, South Africa, and parts of Antarctica, at 1:00; asteroid 4 Vesta (magnitude +6.0) is at opposition at 3:00
9/30 Mercury is in inferior conjunction at 15:00
Karl Harding discovered asteroid 3 Juno on September 1, 1804. E. E. Barnard discovered Jupiter’s fifth satellite, fourteenth-magnitude Amalthea, using the 36-inch refractor at the Lick Observatory on September 9, 1892. On September 19, 1848, William Bond discovered Saturn’s fourteenth-magnitude satellite Hyperion, the first irregular moon to be discovered. Neptune was discovered by Johann Gottfried Galle on September 23, 1846, using Urbain Le Verrier’s calculations of its position.
The minor meteor shower known as the Epsilon Perseids, which has a maximum hourly rate of just 5 per hour, peaks on the evening of September 9th. The radiant is located near the second-magnitude star Algol (Beta Persei) at 03h15m, +40 degrees.
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 www.heavens-above.com/
The zodiacal light, or the false dawn, is visible about two hours before sunrise from a dark site during the latter part of September. Articles on the zodiacal light appear at www.atoptics.co.uk/highsky/zod1.htm and oneminuteastronomer.com/6645/zodiacal-light/
The Moon is 17.4 days old, is illuminated 92.8%, and is located in Cetus on September 1st at 0:00 UT. A perigean Full Moon, a so-called supermoon, occurs on the night of September 27th (September 28th UT). Large tides occur on September 1st, 2nd, 3rd, 28th, 29th, and 30th. A total lunar eclipse occurs on the night of September 27th. Partial eclipse begins at 9:07 p.m. EDT and ends at 12:27 a.m. EDT. Totality begins at 10:11 p.m. EDT and ends at 11:23 EDT. Greatest eclipse takes place at 10:47 a.m. EDT. Refer to pages 56-59 of the September issue of Astronomy, pages 26-29 of the September issue of Sky & Telescope, or www.eclipsewise.com/lunar/LEnews/TLE2015Sep28/TLE2015Sep28.html for more on this event. The Moon is at its greatest northern declination (+18.2 degrees) on September 6th and its greatest southern declination (-18.1 degrees) on September 21st. Longitudinal libration is at a maximum of +7.4 degrees on September 6th and a minimum of -7.5 degrees on September 21st. Latitudinal libration is at a maximum of +6.8 degrees on September 6th and a minimum of -6.8 degrees on September 21st. The Last Quarter Moon occults the first-magnitude star Aldebaran on September 5th. Consult www.lunar-occultations.com/iota/iotandx.htm or page 51 of the September issue of Sky & Telescope for further information. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons and www.curtrenz.com/moon06.html for Full Moon data. Times and dates for the lunar light rays predicted to occur in June are available at www.lunar-occultations.com/rlo/rays/rays.htm
The Sun is located in Leo on September 1st. A partial solar eclipse that's visible from southern Africa, the southern Indian Ocean, and Antarctica takes place on September 13th. Click on www.eclipsewise.com/solar/SEprime/2001-2100/SE2015Sep13Pprime.html for additional information. The Sun crosses the celestial equator from north to south at 8:21 UT on September 23rd, the date of the autumnal equinox.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on September 1st: Mercury (magnitude +0.1, 6.8", 60% illuminated, 0.99 a.u., Virgo), Venus (magnitude -4.5, 51.5", 9% illuminated, 0.32 a.u., Cancer), Mars (magnitude +1.8, 3.7", 98% illuminated, 2.51 a.u., Cancer), Jupiter (magnitude -1.7, 30.8", 100% illuminated, 6.40 a.u., Leo), Saturn (magnitude +0.5, 16.4", 100% illuminated, 10.11 a.u., Libra), Uranus (magnitude +5.7, 3.7", 100% illuminated, 19.08 a.u. on September 16th, Pisces), Neptune (magnitude +7.8, 2.4", 100% illuminated, 29.00 a.u. on September 16th, Aquarius), and Pluto (magnitude +14.2, 0.1", 100% illuminated, 32.59 a.u. on September 16th, Sagittarius).
This month Mercury is located in the west, Saturn in the southwest, and Neptune in the southeast during the evening. At midnight, Uranus can be found in the southeast and Neptune in the south. Venus, Mars, and Jupiter are in the east and Uranus is in the southwest in the morning sky.
For observers at latitude 40 degrees north at midmonth, Mercury is visible during evening twilight, Venus rises at 4:00 a.m. local time, Mars rises at 4:00 a.m. local time, Jupiter rises at 5:00 a.m. local time, and Saturn sets at 10:00 p.m. local time.
Mercury lies low in the west just after sunset this month. Southern hemisphere observers are favored for this month’s evening apparition of the planet. Mercury reaches a greatest eastern elongation of 27 degrees on September 4th but will remain close to the horizon, setting approximately 50 minutes after the Sun, due to the angle of the ecliptic. The speediest planet is 5 degrees south of the Moon on September 15th and is stationary on September 17th. On September 19th, Mercury is at its greatest heliocentric latitude south. It is in inferior conjunction on September 30th.
During September, Venus shrinks in apparent size from 52 to 33 arc seconds but grows in illumination from 9 to 34%. Venus is stationary on September 5th and is three degrees south of the Moon on September 10th. On September 21st, Venus attains maximum brightness (magnitude -4.8), as the planet reaches its greatest illuminated extent. The brightest planet exits Cancer and enters Leo on September 24th.
Mars departs Cancer and enters Leo on September 4th. The Red Planet is five degrees north of the Moon on September 10th. Mars passes than a degree north of the first-magnitude star Regulus on September 24th.
Jupiter reappears in the morning sky by the middle of September. It increases slightly in apparent diameter to 31.4 arc seconds and rises two hours before the Sun by month’s end. Browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/ to determine transit times of the central meridian by the Great Red Spot. Data on the Galilean satellites is available at d366w3m5tf0813.cloudfront.net/wp-content/uploads/WebJphenTab2015.pdf and www.shallowsky.com/jupiter/
Saturn sets about 10:00 p.m. local daylight time this month. Its rings span 37 arc seconds and are tilted 24.3 degrees with respect to the Earth. The distance between Saturn and Graffias (Beta Scorpii) decreases from four to two degrees this month. The Ringed Planet is 3 degrees south of the Moon on September 19th. Eighth-magnitude Titan, Saturn’s largest satellite, is due north of Saturn on September 7th and September 23rd and is due south on September 15th. For further information on Saturn’s satellites, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
Uranus is located 0.5 degree due south of the fifth-magnitude star Zeta Piscium at the start of September. By the end of the month, the gap widens to 1.2 degrees and Uranus lies to the southwest of the star.
Neptune (magnitude +7.8, apparent size 2.4") reaches opposition at midnight on the night of August 31st for American observers and is well-positioned for observation in September. The eighth planet lies approximately halfway between the fourth-magnitude star Lambda Aquarii and the fifth-magnitude star Sigma Aquarii. It passes 3.6 arc minutes due north of a seventh-magnitude star on September 4th.
Finder charts for Uranus and Neptune can be found on page 49 of the September issue of Sky & Telescope and online at www.nakedeyeplanets.com/uranus.htm and www.nakedeyeplanets.com/neptune.htm and at www.skyandtelescope.com/wp-content/uploads/WEB_UrNep_Finders.pdf
Finder charts for Pluto are available on pages 52 and 53 of the July issue of Sky & Telescope and page 47 of the July issue of Astronomy and online at www.bluewaterastronomy.info/resources/MapsCharts/planets-2015/22pluto_2015_1.pdf
For more on the planets and how to locate them, see www.nakedeyeplanets.com/
The periodic comet 67P/Churyumov-Gerasimenko, the target of the Rosetta mission, may be bright enough to observe in the morning sky this month. It passes one degree south of the sixth-magnitude star Lambda Cancri on September 10th. On the mornings of September 16th and September 17th, the comet passes about two degrees north of the bright open cluster M44 (the Beehive). It’s located 0.4 degree north of the fifth-magnitude star Gamma Cancri on September 17th. Another periodic comet, 141P/Machholz, comes within one degree of 67P/Churyumov-Gerasimenko on the morning of September 1st but bright moonlight will make observing the event very difficult. The remarkable C/2014 Q2 (Lovejoy) is still a potential target as it moves through Boötes. For further information on comets visible in September, browse cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html
Asteroid Metis (magnitude +8.8) is at opposition in Aquarius on the night of September 5th. Asteroid 4 Vesta (magnitude +6.0) is at opposition in Cetus on the night of September 28th. Asteroids 22 Kalliope, 13 Egeria, and 45 Eugenia all shine at eleventh-magnitude as they reach opposition on September 8th, September 13th, and September 16th respectively. Noteworthy asteroid occultations occur this month on September 1st (849 Ara), September 3rd (112 Iphigenia), and September 23rd (51 Nemausa) for observers living in various parts of North America. Data on these and other asteroid occultations taking place this month is available at www.asteroidoccultation.com/2015_09_si.htm and www.poyntsource.com/New/Global.htm
Free star maps for August can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
On September 22nd, the eclipsing variable star Algol (Beta Persei) shines at minimum brightness (magnitude +3.4) for approximately two hours on centered on 11:20 p.m. EDT.
Eighty binary and multiple stars for September: 12 Aquarii, Struve 2809, Struve 2838 (Aquarius); Alpha Capricorni, Sigma Capricorni, Nu Capricorni, Beta Capricorni, Pi Capricorni, Rho Capricorni, Omicron Capricorni, h2973, h2975, Struve 2699, h2995, 24 Capricorni, Xi Capricorni, Epsilon Capricorni, 41 Capricorni, h3065 (Capricornus); Kappa Cephei, Struve 2751, Beta Cephei, Struve 2816, Struve 2819, Struve 2836, Otto Struve 451, Struve 2840, Struve 2873 (Cepheus); Otto Struve 394, 26 Cygni, h1470, h1471, Omicron Cygni, Struve 2657, 29 Cygni, 49 Cygni, 52 Cygni, 59 Cygni, 60 Cygni, 61 Cygni, Struve 2762 (Cygnus); Struve 2665, Struve 2673, Struve 2679, Kappa Delphini, Struve 2715, Struve 2718, Struve 2721, Struve 2722, Struve 2725 (in the same field as Gamma Delphini), Gamma Delphini, 13 Delphini, Struve 2730, 16 Delphini, Struve 2735, Struve 2736, Struve 2738 (Delphinus); 65 Draconis, Struve 2640 (Draco); Epsilon Equulei, Lambda Equulei, Struve 2765, Struve 2786, Struve 2793 (Equuleus); 1 Pegasi, Struve 2797, h1647, Struve 2804, Struve 3112, 3 Pegasi, 4 Pegasi, Kappa Pegasi, h947, Struve 2841, Struve 2848 (Pegasus); h1462, Struve 2653, Burnham 441, Struve 2655, Struve 2769 (Vulpecula)
Notable carbon star for September: LW Cygni
Forty-five deep-sky objects for September: M2, M72, M73, NGC 7009 (Aquarius); M30, NGC 6903, NGC 6907 (Capricornus); B150, B169, B170, IC 1396, NGC 6939, NGC 4343, B361, Ba6, Be87, Cr 421, Do9, IC 1369, IC 4996, IC 1516, LDN 906, M29, M39, NGC 6866, NGC 6871, NGC 6888, NGC 6894, NGC 6910, NGC 6960, NGC 6992, NGC 7000, NGC 7008, NGC 7026, NGC 7027, NGC 7039, NGC 7063, NGC 7086 (Cygnus); NGC 6891, NGC 6905, NGC 6934, NGC 7006 (Delphinus); NGC 7015 (Equuleus); M15 (Pegasus); NGC 6940 (Vulpecula)
Top ten binocular deep-sky objects for September: IC 1396, LDN 906, M2, M15, M29, M30, M39, NGC 6939, NGC 6871, NGC 7000
Top ten deep-sky objects for September: IC 1396, M2, M15, M30, NGC 6888, NGC 6946, NGC 6960, NGC 6992, NGC 7000, NGC 7009
Challenge deep-sky object for September: Abell 78 (Cygnus)
The objects listed above are located between 20:00 and 22:00 hours of right ascension.
All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)
9/1 Neptune (magnitude +7.8, apparent size 2.4") is at opposition at 4:00; Uranus is 1.1 degrees north of the Moon, with an occultation taking place in most of New Zealand and parts of Antarctica, at 16:00
9/4 Mercury is at its greatest eastern elongation (27 degrees) at 10:00
9/5 The Moon is 0.5 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation taking place in northwestern Asia, western Russia, Europe, and eastern North America, at 6:00; Last Quarter Moon occurs at 9:54; Venus is stationary at 9:00
9/6 Asteroid Metis (magnitude +8.8) is at opposition at 3:00
9/7 The Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to occur at 3:50
9/10 Venus is 3 degrees south of the Moon at 6:00; Mars is 5 degrees north of the Moon at 23:00
9/13 A partial solar eclipse visible from southern Africa, the southern Indian Ocean, and Antarctica begins at 4:41; New Moon (lunation 1147) occurs at 6:41
9/14 The Moon is at apogee, subtending 29' 20" from a distance of 406,464 kilometers (252,565 miles), at 11:00
9/15 Mercury is 5 degrees south of the Moon at 6:00; asteroid 1 Ceres is stationary at 18:00
9/17 Mercury is stationary at 13:00
9/19 Mercury is at its greatest heliocentric latitude south today; Saturn is 3 degrees south of the Moon at 3:00
9/20 The Lunar X (the Purbach or Werner Cross), an X-shaped illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to occur at 13:56
9/21 First Quarter Moon occurs at 8:59
9/23 The autumnal equinox occurs in the northern hemisphere at 8:21
9/24 Mars is 0.8 degree north of the first-magnitude star Regulus (Alpha Leonis) at 17:00; Pluto is stationary at 19:00
9/26 Neptune is 3 degrees south of the Moon at 10:00
9/28 The Moon is at perigee, subtending 33' 50" from a distance of 356,877 kilometers (221,753 miles), at 2:00; a total lunar eclipse begins at 2:11 and ends at 3:23; Full Moon (known as the Barley, Corn, or Fruit Moon), the largest of 2015 and this year’s Harvest Moon, occurs at 2:51
9/29 Uranus is 1.0 degree north of the Moon, with an occultation taking place in the southern portion of Madagascar, South Africa, and parts of Antarctica, at 1:00; asteroid 4 Vesta (magnitude +6.0) is at opposition at 3:00
9/30 Mercury is in inferior conjunction at 15:00
Karl Harding discovered asteroid 3 Juno on September 1, 1804. E. E. Barnard discovered Jupiter’s fifth satellite, fourteenth-magnitude Amalthea, using the 36-inch refractor at the Lick Observatory on September 9, 1892. On September 19, 1848, William Bond discovered Saturn’s fourteenth-magnitude satellite Hyperion, the first irregular moon to be discovered. Neptune was discovered by Johann Gottfried Galle on September 23, 1846, using Urbain Le Verrier’s calculations of its position.
The minor meteor shower known as the Epsilon Perseids, which has a maximum hourly rate of just 5 per hour, peaks on the evening of September 9th. The radiant is located near the second-magnitude star Algol (Beta Persei) at 03h15m, +40 degrees.
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 www.heavens-above.com/
The zodiacal light, or the false dawn, is visible about two hours before sunrise from a dark site during the latter part of September. Articles on the zodiacal light appear at www.atoptics.co.uk/highsky/zod1.htm and oneminuteastronomer.com/6645/zodiacal-light/
The Moon is 17.4 days old, is illuminated 92.8%, and is located in Cetus on September 1st at 0:00 UT. A perigean Full Moon, a so-called supermoon, occurs on the night of September 27th (September 28th UT). Large tides occur on September 1st, 2nd, 3rd, 28th, 29th, and 30th. A total lunar eclipse occurs on the night of September 27th. Partial eclipse begins at 9:07 p.m. EDT and ends at 12:27 a.m. EDT. Totality begins at 10:11 p.m. EDT and ends at 11:23 EDT. Greatest eclipse takes place at 10:47 a.m. EDT. Refer to pages 56-59 of the September issue of Astronomy, pages 26-29 of the September issue of Sky & Telescope, or www.eclipsewise.com/lunar/LEnews/TLE2015Sep28/TLE2015Sep28.html for more on this event. The Moon is at its greatest northern declination (+18.2 degrees) on September 6th and its greatest southern declination (-18.1 degrees) on September 21st. Longitudinal libration is at a maximum of +7.4 degrees on September 6th and a minimum of -7.5 degrees on September 21st. Latitudinal libration is at a maximum of +6.8 degrees on September 6th and a minimum of -6.8 degrees on September 21st. The Last Quarter Moon occults the first-magnitude star Aldebaran on September 5th. Consult www.lunar-occultations.com/iota/iotandx.htm or page 51 of the September issue of Sky & Telescope for further information. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons and www.curtrenz.com/moon06.html for Full Moon data. Times and dates for the lunar light rays predicted to occur in June are available at www.lunar-occultations.com/rlo/rays/rays.htm
The Sun is located in Leo on September 1st. A partial solar eclipse that's visible from southern Africa, the southern Indian Ocean, and Antarctica takes place on September 13th. Click on www.eclipsewise.com/solar/SEprime/2001-2100/SE2015Sep13Pprime.html for additional information. The Sun crosses the celestial equator from north to south at 8:21 UT on September 23rd, the date of the autumnal equinox.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on September 1st: Mercury (magnitude +0.1, 6.8", 60% illuminated, 0.99 a.u., Virgo), Venus (magnitude -4.5, 51.5", 9% illuminated, 0.32 a.u., Cancer), Mars (magnitude +1.8, 3.7", 98% illuminated, 2.51 a.u., Cancer), Jupiter (magnitude -1.7, 30.8", 100% illuminated, 6.40 a.u., Leo), Saturn (magnitude +0.5, 16.4", 100% illuminated, 10.11 a.u., Libra), Uranus (magnitude +5.7, 3.7", 100% illuminated, 19.08 a.u. on September 16th, Pisces), Neptune (magnitude +7.8, 2.4", 100% illuminated, 29.00 a.u. on September 16th, Aquarius), and Pluto (magnitude +14.2, 0.1", 100% illuminated, 32.59 a.u. on September 16th, Sagittarius).
This month Mercury is located in the west, Saturn in the southwest, and Neptune in the southeast during the evening. At midnight, Uranus can be found in the southeast and Neptune in the south. Venus, Mars, and Jupiter are in the east and Uranus is in the southwest in the morning sky.
For observers at latitude 40 degrees north at midmonth, Mercury is visible during evening twilight, Venus rises at 4:00 a.m. local time, Mars rises at 4:00 a.m. local time, Jupiter rises at 5:00 a.m. local time, and Saturn sets at 10:00 p.m. local time.
Mercury lies low in the west just after sunset this month. Southern hemisphere observers are favored for this month’s evening apparition of the planet. Mercury reaches a greatest eastern elongation of 27 degrees on September 4th but will remain close to the horizon, setting approximately 50 minutes after the Sun, due to the angle of the ecliptic. The speediest planet is 5 degrees south of the Moon on September 15th and is stationary on September 17th. On September 19th, Mercury is at its greatest heliocentric latitude south. It is in inferior conjunction on September 30th.
During September, Venus shrinks in apparent size from 52 to 33 arc seconds but grows in illumination from 9 to 34%. Venus is stationary on September 5th and is three degrees south of the Moon on September 10th. On September 21st, Venus attains maximum brightness (magnitude -4.8), as the planet reaches its greatest illuminated extent. The brightest planet exits Cancer and enters Leo on September 24th.
Mars departs Cancer and enters Leo on September 4th. The Red Planet is five degrees north of the Moon on September 10th. Mars passes than a degree north of the first-magnitude star Regulus on September 24th.
Jupiter reappears in the morning sky by the middle of September. It increases slightly in apparent diameter to 31.4 arc seconds and rises two hours before the Sun by month’s end. Browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/ to determine transit times of the central meridian by the Great Red Spot. Data on the Galilean satellites is available at d366w3m5tf0813.cloudfront.net/wp-content/uploads/WebJphenTab2015.pdf and www.shallowsky.com/jupiter/
Saturn sets about 10:00 p.m. local daylight time this month. Its rings span 37 arc seconds and are tilted 24.3 degrees with respect to the Earth. The distance between Saturn and Graffias (Beta Scorpii) decreases from four to two degrees this month. The Ringed Planet is 3 degrees south of the Moon on September 19th. Eighth-magnitude Titan, Saturn’s largest satellite, is due north of Saturn on September 7th and September 23rd and is due south on September 15th. For further information on Saturn’s satellites, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
Uranus is located 0.5 degree due south of the fifth-magnitude star Zeta Piscium at the start of September. By the end of the month, the gap widens to 1.2 degrees and Uranus lies to the southwest of the star.
Neptune (magnitude +7.8, apparent size 2.4") reaches opposition at midnight on the night of August 31st for American observers and is well-positioned for observation in September. The eighth planet lies approximately halfway between the fourth-magnitude star Lambda Aquarii and the fifth-magnitude star Sigma Aquarii. It passes 3.6 arc minutes due north of a seventh-magnitude star on September 4th.
Finder charts for Uranus and Neptune can be found on page 49 of the September issue of Sky & Telescope and online at www.nakedeyeplanets.com/uranus.htm and www.nakedeyeplanets.com/neptune.htm and at www.skyandtelescope.com/wp-content/uploads/WEB_UrNep_Finders.pdf
Finder charts for Pluto are available on pages 52 and 53 of the July issue of Sky & Telescope and page 47 of the July issue of Astronomy and online at www.bluewaterastronomy.info/resources/MapsCharts/planets-2015/22pluto_2015_1.pdf
For more on the planets and how to locate them, see www.nakedeyeplanets.com/
The periodic comet 67P/Churyumov-Gerasimenko, the target of the Rosetta mission, may be bright enough to observe in the morning sky this month. It passes one degree south of the sixth-magnitude star Lambda Cancri on September 10th. On the mornings of September 16th and September 17th, the comet passes about two degrees north of the bright open cluster M44 (the Beehive). It’s located 0.4 degree north of the fifth-magnitude star Gamma Cancri on September 17th. Another periodic comet, 141P/Machholz, comes within one degree of 67P/Churyumov-Gerasimenko on the morning of September 1st but bright moonlight will make observing the event very difficult. The remarkable C/2014 Q2 (Lovejoy) is still a potential target as it moves through Boötes. For further information on comets visible in September, browse cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html
Asteroid Metis (magnitude +8.8) is at opposition in Aquarius on the night of September 5th. Asteroid 4 Vesta (magnitude +6.0) is at opposition in Cetus on the night of September 28th. Asteroids 22 Kalliope, 13 Egeria, and 45 Eugenia all shine at eleventh-magnitude as they reach opposition on September 8th, September 13th, and September 16th respectively. Noteworthy asteroid occultations occur this month on September 1st (849 Ara), September 3rd (112 Iphigenia), and September 23rd (51 Nemausa) for observers living in various parts of North America. Data on these and other asteroid occultations taking place this month is available at www.asteroidoccultation.com/2015_09_si.htm and www.poyntsource.com/New/Global.htm
Free star maps for August can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart
On September 22nd, the eclipsing variable star Algol (Beta Persei) shines at minimum brightness (magnitude +3.4) for approximately two hours on centered on 11:20 p.m. EDT.
Eighty binary and multiple stars for September: 12 Aquarii, Struve 2809, Struve 2838 (Aquarius); Alpha Capricorni, Sigma Capricorni, Nu Capricorni, Beta Capricorni, Pi Capricorni, Rho Capricorni, Omicron Capricorni, h2973, h2975, Struve 2699, h2995, 24 Capricorni, Xi Capricorni, Epsilon Capricorni, 41 Capricorni, h3065 (Capricornus); Kappa Cephei, Struve 2751, Beta Cephei, Struve 2816, Struve 2819, Struve 2836, Otto Struve 451, Struve 2840, Struve 2873 (Cepheus); Otto Struve 394, 26 Cygni, h1470, h1471, Omicron Cygni, Struve 2657, 29 Cygni, 49 Cygni, 52 Cygni, 59 Cygni, 60 Cygni, 61 Cygni, Struve 2762 (Cygnus); Struve 2665, Struve 2673, Struve 2679, Kappa Delphini, Struve 2715, Struve 2718, Struve 2721, Struve 2722, Struve 2725 (in the same field as Gamma Delphini), Gamma Delphini, 13 Delphini, Struve 2730, 16 Delphini, Struve 2735, Struve 2736, Struve 2738 (Delphinus); 65 Draconis, Struve 2640 (Draco); Epsilon Equulei, Lambda Equulei, Struve 2765, Struve 2786, Struve 2793 (Equuleus); 1 Pegasi, Struve 2797, h1647, Struve 2804, Struve 3112, 3 Pegasi, 4 Pegasi, Kappa Pegasi, h947, Struve 2841, Struve 2848 (Pegasus); h1462, Struve 2653, Burnham 441, Struve 2655, Struve 2769 (Vulpecula)
Notable carbon star for September: LW Cygni
Forty-five deep-sky objects for September: M2, M72, M73, NGC 7009 (Aquarius); M30, NGC 6903, NGC 6907 (Capricornus); B150, B169, B170, IC 1396, NGC 6939, NGC 4343, B361, Ba6, Be87, Cr 421, Do9, IC 1369, IC 4996, IC 1516, LDN 906, M29, M39, NGC 6866, NGC 6871, NGC 6888, NGC 6894, NGC 6910, NGC 6960, NGC 6992, NGC 7000, NGC 7008, NGC 7026, NGC 7027, NGC 7039, NGC 7063, NGC 7086 (Cygnus); NGC 6891, NGC 6905, NGC 6934, NGC 7006 (Delphinus); NGC 7015 (Equuleus); M15 (Pegasus); NGC 6940 (Vulpecula)
Top ten binocular deep-sky objects for September: IC 1396, LDN 906, M2, M15, M29, M30, M39, NGC 6939, NGC 6871, NGC 7000
Top ten deep-sky objects for September: IC 1396, M2, M15, M30, NGC 6888, NGC 6946, NGC 6960, NGC 6992, NGC 7000, NGC 7009
Challenge deep-sky object for September: Abell 78 (Cygnus)
The objects listed above are located between 20:00 and 22:00 hours of right ascension.