Post by Dave Mitsky on Sept 13, 2022 4:30:27 GMT
September 2022 Celestial Calendar by Dave Mitsky
All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)
9/3 The Lunar X, also known as the Werner or Purbach Cross, an X-shaped clair-obscur illumination effect involving various ridges and crater rims located between the craters La Caille, Blanchinus, and Purbach, is predicted to be visible at 7:11; First Quarter Moon occurs at 18:08
9/4 Venus is at perihelion today
9/5 Venus is 0.8 degrees north of the first-magnitude star Regulus (Alpha Leonis) at 1:00
9//7 Mars is 4.3 degrees north of the first-magnitude star Aldebaran (Alpha Tauri) at 12:00; asteroid 3 Juno (magnitude +7.8) is at opposition in Aquarius at 17:00; the Moon is at perigee, subtending 32' 47" from a distance of 364,494 kilometers (226,485 miles), at 18:19
9/8 The Moon is 4 degrees south of Saturn at 11:00
9/9 The Moon is 4 degrees north of Mars at 1:00; Mercury is stationary at 20:00
9/10 Full Moon (known as the Barley, Corn, or Fruit Moon, and this year's Harvest Moon) occurs at 9:59; the Moon is 3 degrees south of Neptune at 19:00
9/11 The Moon is 1.8 degrees south of Jupiter at 15:00
9/13 Mercury is at its greatest heliocentric latitude south today
9/14 The Moon is 0.8 degrees north of Uranus, with an occultation taking place in northwestern Alaska, the northernmost portion of Canada, Greenland, most of Russia, portions of the Middle East, Europe, and most of northern Africa, at 23:00
9/16 Neptune (magnitude +7.8, angular diameter 2.4") is at opposition at 23:00
9/17 The Moon is 4 degrees north of Mars at 2:00; Last Quarter Moon occurs at 21:52
9/19 The Curtiss Cross, an X-shaped clair-obscur illumination effect located between the craters Parry and Gambart, is predicted to be visible at 6:45; the Moon is at apogee, subtending 29' 32" from a distance of 404,555 kilometers (251,379 miles), at 14:43
9/20 The Moon is 1.9 degrees south of the first magnitude star Pollux (Beta Geminorum) at 8:00
9/23 The northern hemisphere autumnal equinox occurs at 1:04; Mercury reaches inferior conjunction at 7:00
9/25 New Moon (lunation 1234) occurs at 21:54
9/26 Venus is at its greatest heliocentric latitude north today; Jupiter (magnitude -2.9, angular diameter 49.8") is at opposition at 20:00
Jean-Dominique Maraldi discovered the globular cluster M15 on September 7, 1746. On September 11, 1746, Jean-Dominique Maraldi discovered the globular cluster M2. Nicolas-Louis de Lacaille discovered NGC 104 (47 Tucanae), the second largest and brightest globular cluster, on September 14th, 1751. William Herschel discovered the barred spiral galaxy NGC 7753 on September 12, 1784. William Herschel discovered the Saturnian satellite Mimas on September 17, 1789. Comet C/1793 S2 (Messier) was discovered by Charles Messier on September 27th, 1793. Karl Harding discovered asteroid 3 Juno on September 1, 1804. Neptune was discovered by Johann Gottfried Galle on September 23, 1846, using Urbain Le Verrier’s calculations of its position. On September 19, 1848, William Bond discovered Saturn’s fourteenth-magnitude satellite Hyperion, the first irregular moon to be discovered. On September 13, 1850, John Russell Hind discovered the asteroid 12 Victoria. E. E. Barnard discovered Jupiter’s fifth satellite, fourteenth-magnitude Amalthea, using the 36-inch refractor at the Lick Observatory, on September 9, 1892.
Only very minor meteor showers occur this month.
Information on passes of the ISS, the USAF’s X-37B, the HST, Starlink, and other satellites can be found at www.heavens-above.com/
The Moon is 4.5 days old, is illuminated 20.2%, subtends 31.3 arc minutes, and is located in Virgo on September 1st at 00:00 UT. The Moon is at its greatest northern declination on September 19th (+27.3 degrees) and its greatest southern declination on September 6th (-27.1 degrees). Longitudinal libration is at a maximum of +6.4 degrees on September 13th and a minimum of -5.3 degrees on September 1st and -4.5 degrees on September 27th. Latitudinal libration is at a maximum of +6.6 degrees on September 8th and a minimum of -6.7 degrees on September 22nd. Favorable librations for the following lunar features occur on the indicated dates: Crater Byrd on September 8th, Crater Cusanus on September 9th, Mare Humboldtianum on September 10th, and Crater Bailly on September 22nd. Full Moon occurs on September 10th. New Moon (i.e., the dark of the Moon) occurs on September 25th. The Moon passes near the first-magnitude star Antares (Alpha Scorpii) at 17:00 on September 3rd, the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 22:00 on September 15th, the first-magnitude star Aldebaran (Alpha Tauri) at 16:00 on September 16th, the bright open cluster M35 in Gemini at 13:00 on September 18th, the first-magnitude star Castor (Alpha Geminorum) at 3:00 on September 20th, the first-magnitude star Pollux (Beta Geminorum) at 8:00 on September 20th, the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 13:00 on September 21st, the first-magnitude star Regulus (Alpha Leonis) at 9:00 on September 23rd, the first-magnitude star Spica (Alpha Virginis) at 14:00 on September 27th, and the first-magnitude star Antares (Alpha Scorpii) again at 23:00 on September 30th. Browse www.lunar-occultations.com/iota/iotandx.htm for information on lunar occultation events. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons and curtrenz.com/moon.html for Full Moon and other lunar data. Browse skyandtelescope.org/wp-content/uploads/MoonMap.pdf and nightsky.jpl.nasa.gov/docs/ObserveMoon.pdf for simple lunar maps. Click on astrostrona.pl/moon-map for an excellent online lunar map. Visit www.ap-i.net/avl/en/start to download the free Virtual Moon Atlas. Consult time.unitarium.com/moon/where.html for current information on the Moon and www.fourmilab.ch/earthview/lunarform/lunarform.html for information on various lunar features. See svs.gsfc.nasa.gov/4874 for a lunar phase and libration calculator and quickmap.lroc.asu.edu/?extent=-90,-25.2362636,90,25.2362636&proj=10&layers=NrBsFYBoAZIRnpEoAsjYIHYFcA2vIBvAXwF1SizSg for the Lunar Reconnaissance Orbiter Camera (LROC) Quickmap. Click on www.calendar-12.com/moon_calendar/2022/september 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 www.lunar-occultations.com/rlo/rays/rays.htm
The zodiacal light, or the false dawn, is visible about two hours before sunrise from a dark site for two weeks beginning on September 23rd. It can be seen in Leo, Cancer, Gemini, and Taurus. Articles on the zodiacal light appear at www.atoptics.co.uk/highsky/zod1.htm and oneminuteastronomer.com/6645/zodiacal-light/
The Sun is located in Leo on September 1st. It enters Virgo on September 16th. The Sun crosses the celestial equator from north to south at 1:04 UT on September 23rd (9:04 p.m. EDT on September 22nd), the date of the northern hemisphere 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 +0.3, 7.8", 46% illuminated, 0.86 a.u., Virgo), Venus (magnitude -3.9., 10.1", 97% illuminated, 1.66 a.u., Virgo), Mars (magnitude -0.1, 9.8", 85% illuminated, 0.96 a.u., Leo), Jupiter (magnitude -2.9, 48.7", 100% illuminated, 4.05 a.u., Capricornus), Saturn (magnitude +0.3, 18.7", 100% illuminated, 8.90 a.u., Capricornus), Uranus (magnitude +5.7, 3.7", 100% illuminated, 19.10 a.u. on September 16th, Aries), Neptune (magnitude +7.8, 2.4", 100% illuminated, 28.91 a.u. on September 16th, Aquarius), and Pluto (magnitude +14.3, 0.1", 100% illuminated, 34.05 a.u. on September 16th, Sagittarius).
During the month of September, Jupiter and Neptune are located in the east, Saturn is located in the southeast, and Mercury is located in the west, in the evening. At midnight, Mars and Uranus can be found in the east, Jupiter in the southeast, and Saturn and Neptune in the south. Venus is in the east, Mars is in the south, Uranus is in the southwest, and Jupiter and Neptune are in the west in the morning sky.
Mercury is not well-placed for northern hemisphere observers this month. The speediest planet is stationary on September 9th and is at its greatest heliocentric latitude south on September 13th. It reaches inferior conjunction on September 23rd.
Venus is at perihelion on September 4th. It passes less than one degree north of Regulus on September 5th and reaches greatest heliocentric latitude north on September 26th. The brightest planet can be seen during bright early morning twilight early in September. However, its elongation from the Sun drops to ten degrees by September 15th and to six degrees by the end of the month. A waning crescent Moon lies nine degrees from Venus on September 24th.
Mars brightens from magnitude -0.1 to magnitude -0.6 and increases in apparent size from 9.8 to 10.7 arc seconds during September. The following Martian surface features are well-placed not long after midnight: the Tharsis Ridge on September 1st, Valles Marineris on September 8th, Hellas Basin and Syrtis Major on September 14th, Mare Cimmerium and Syrtis Major on September 22nd, and Mare Sirenum on September 30th. The apparent diameter of Mars exceeds 10 arc seconds on September 4th. The Red Planet passes approximately four degrees north of Aldebaran on September 9th UT. The Last Quarter Moon passes four degrees to the north of Mars on September 17th. The apparent brightness of Mars exceeds magnitude -0.5 on September 26th.
Jupiter shines at magnitude -2.9, subtends 49.9 arc seconds, is 33 light minutes from the Earth, and lies within one arc minute of the celestial equator when it reaches opposition on September 26th. This will be the closest opposition since October 8,1963. Jupiter’s retrograde motion is at a maximum and the Galilean satellites are at their brightest and widest apparent separation at opposition. At opposition transits of the satellites and their shadows occur almost simultaneously. The shadows precede the satellites prior to opposition and follow them after opposition. Callisto lies due south of Jupiter on the night of September 4th/5th. The just past Full gibbous Moon passes less than two degrees south of the Jupiter on September 11th. An article on observing Jupiter can be found on pages 48 and 49 of the September 2022 issue of Sky & Telescope. Information on Great Red Spot transit times and Galilean satellite events is available on pages 50 and 51 of the September 2022 issue of Sky & Telescope and online at www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and shallowsky.com/jupiter/
This month Saturn fades from magnitude +0.3 to magnitude +0.5 and shrinks in apparent size from 18.7 arc seconds to 18.1 arc seconds. The apparent tilt of the gas giant planet’s rings increases to 15 degrees by September’s end. Saturn is approximately 20 degrees in altitude by 9:00 p.m. local daylight time early in the month. The waxing gibbous Moon passes four degrees south of the Ringed Planet on September 8th. See pages 46 to 51 of the September 2022 issue of Astronomy for an article on Saturn. Titan, Saturn’s largest and brightest satellite, shines at magnitude +8.5. Titan is due north of the planet on September 6th and September 22nd and due south of it on September 14th and September 30th. The odd satellite Iapetus shines at twelfth magnitude when it is reaches eastern elongation on September 15th. It is almost nine are minutes east of Saturn at that time. For further information on Saturn’s satellites, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
Uranus lies in the middle of a triangle of sixth-magnitude stars, one of which is 43 Arietis, this month. The waning gibbous Moon passes less than one degree north of Uranus and occults it from some locations on September 14th. Visit www.nakedeyeplanets.com/uranus.htm for a finder chart. Five of the brightest Uranian satellites (Miranda, Ariel, Umbriel, Titania, and Oberon) can be located using the Sky & Telescope interactive observing tool at skyandtelescope.org/observing/interactive-sky-watching-tools/the-elusive-moons-ofuranus/
Neptune is located almost five degrees east of the fourth-magnitude star Phi Aquarii as September begins. The ice giant planet lies less than four degrees east of the star at the end of the month. It passes within 1.5 arc minutes of a sixth-magnitude star on September 23rd. Neptune subtends 2.4 arc seconds, shines at magnitude +7.8, and lies at a distance of 4.0 light hours when it reaches opposition on September 16th. See www.nakedeyeplanets.com/neptune.htm for an online finder chart. A finder chart for Neptune appears on page 49 of the September 2022 issue of Sky & Telescope. Triton, Neptune's brightest satellite, can be located using the Sky & Telescope interactive observing tool at skyandtelescope.org/observing/interactive-sky-watching-tools/sky-telescopes-triton-tracker/
Pluto is located low in eastern Sagittarius. Finder charts are available at pages 48 and 49 of the July 2022 issue of Sky & Telescope and on page 239 of the RASC Observer’s Handbook 2022.
For more on the planets and how to locate them, see www.nakedeyeplanets.com/
The Distance, Brightness, and Apparent Size of Planets graphic at www.timeanddate.com/astronomy/planets/distance displays the apparent and comparative sizes of the planets, along with their magnitudes and distances, on a given date and time.
Comet C/2017 K2 (PanSTARRS) continues to head southward through Scorpius and into Lupus. It passes just to the west of Rho Scorpii on September 19th and September 20th. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html and cobs.si/ for additional information on comets visible this month.
Asteroid 4 Vesta shines at sixth-magnitude as it travels southwestward through Aquarius and into Capricornus. Asteroid 3 Juno shines at magnitude +7.8 when it reaches opposition in Aquarius on September 7th. The twelfth-largest asteroid lies with one degree of the fourth-magnitude star Lambda Aquarii from September 20th to September 24th. A finder chart appears on page 49 of the September 2022 issue of Sky & Telescope. Other asteroids brighter than magnitude +11.0 that reach opposition this month include 216 Kleopatra (magnitude +9.9) in Pegasus on September 11th and 128 Nemesis (magnitude +10.8) in Aquarius on September 17th. Data on asteroid occultations taking place this month is available at www.asteroidoccultation.com/2022_09_si.htm and www.poyntsource.com/New/Global.htm
A wealth of current information on solar system celestial bodies is posted at nineplanets.org/ and www.curtrenz.com/astronomy.html
Information on the celestial events transpiring each week can be found at stardate.org/nightsky and astronomy.com/skythisweek and www.skyandtelescope.com/observing/sky-at-a-glance/
An online data generator for various astronomical events is available at astronomynow.com/almanac/
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in brightness from magnitude +2.1 to magnitude +3.4, on September 2nd, 5th, 8th, 11th, 14th, 17th, 20th, 22nd, 25th, and 28th. Consult skyandtelescope.org/observing/the-minima-of-algol/ or page 50 of the September 2022 issue of Sky & Telescope for the minima times. On the morning of September 15th, Algol shines at minimum brightness (magnitude +3.4) for approximately two hours centered at 12:42 a.m. EDT (4:42 UT September 15th). It does the same at 9:31 p.m. EDT (1:31 UT September 18th) on the night of September 17th. For more on Algol, see stars.astro.illinois.edu/sow/Algol.html and www.solstation.com/stars2/algol3.htm
Free star maps for this month can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart and www.whatsouttonight.com/
Weather and observing conditions forecasts are available at www.cleardarksky.com/csk/index.html
Data on current supernovae can be found at www.rochesterastronomy.org/snimages/
Finder charts for the Messier objects and other deep-sky objects are posted at freestarcharts.com/messier and freestarcharts.com/ngc-ic and www.cambridge.org/turnleft/seasonal_skies_july-september
Telrad finder charts for the Messier Catalog are posted at www.custerobservatory.org/docs/messier2.pdf and www.star-shine.ch/astro/messiercharts/messierTelrad.htm
Telrad finder charts for the SAC’s 110 Best of the NGC are available at sao64.free.fr/observations/catalogues/cataloguesac.pdf
Information pertaining to observing some of the more prominent Messier galaxies can be found at www.cloudynights.com/topic/358295-how-to-locate-some-of-the-major-messier-galaxies-and-helpful-advice-for-novice-amateur-astronomers/
Freeware sky atlases can be downloaded at www.deepskywatch.com/files/deepsky-atlas/Deep-Sky-Hunter-atlas-full.pdf and www.cloudynights.com/articles/cat/articles/observing-skills/free-mag-7-star-charts-r1021 and allans-stuff.com/triatlas/
Author Phil Harrington offers an excellent freeware planetarium program for binocular observers known as TUBA (Touring the Universe through Binoculars Atlas), which also includes information on purchasing binoculars, at www.philharrington.net/tuba.htm
Stellarium and Cartes du Ciel are two excellent freeware planetarium programs that are available at stellarium.org/ and www.ap-i.net/skychart/en/start
Deep-sky object list generators can be found at www.virtualcolony.com/sac/ and telescopius.com/?fromdsobrowser and www.tonightssky.com/MainPage.php
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
Fifty 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 6946, NGC 6951, NGC 7023, NGC 7160, NGC 7142 (Cepheus); B343, B361, Ba6, Be87, Cr 421, Do9, IC 4996, M29, M39, NGC 6866, NGC 6871, NGC 6888, NGC 6894, NGC 6910, NGC 6960, NGC 6992, NGC 6994, NGC 6995, NGC 7000, NGC 7008, NGC 7026, NGC 7027, NGC 7039, NGC 7048, 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)
9/3 The Lunar X, also known as the Werner or Purbach Cross, an X-shaped clair-obscur illumination effect involving various ridges and crater rims located between the craters La Caille, Blanchinus, and Purbach, is predicted to be visible at 7:11; First Quarter Moon occurs at 18:08
9/4 Venus is at perihelion today
9/5 Venus is 0.8 degrees north of the first-magnitude star Regulus (Alpha Leonis) at 1:00
9//7 Mars is 4.3 degrees north of the first-magnitude star Aldebaran (Alpha Tauri) at 12:00; asteroid 3 Juno (magnitude +7.8) is at opposition in Aquarius at 17:00; the Moon is at perigee, subtending 32' 47" from a distance of 364,494 kilometers (226,485 miles), at 18:19
9/8 The Moon is 4 degrees south of Saturn at 11:00
9/9 The Moon is 4 degrees north of Mars at 1:00; Mercury is stationary at 20:00
9/10 Full Moon (known as the Barley, Corn, or Fruit Moon, and this year's Harvest Moon) occurs at 9:59; the Moon is 3 degrees south of Neptune at 19:00
9/11 The Moon is 1.8 degrees south of Jupiter at 15:00
9/13 Mercury is at its greatest heliocentric latitude south today
9/14 The Moon is 0.8 degrees north of Uranus, with an occultation taking place in northwestern Alaska, the northernmost portion of Canada, Greenland, most of Russia, portions of the Middle East, Europe, and most of northern Africa, at 23:00
9/16 Neptune (magnitude +7.8, angular diameter 2.4") is at opposition at 23:00
9/17 The Moon is 4 degrees north of Mars at 2:00; Last Quarter Moon occurs at 21:52
9/19 The Curtiss Cross, an X-shaped clair-obscur illumination effect located between the craters Parry and Gambart, is predicted to be visible at 6:45; the Moon is at apogee, subtending 29' 32" from a distance of 404,555 kilometers (251,379 miles), at 14:43
9/20 The Moon is 1.9 degrees south of the first magnitude star Pollux (Beta Geminorum) at 8:00
9/23 The northern hemisphere autumnal equinox occurs at 1:04; Mercury reaches inferior conjunction at 7:00
9/25 New Moon (lunation 1234) occurs at 21:54
9/26 Venus is at its greatest heliocentric latitude north today; Jupiter (magnitude -2.9, angular diameter 49.8") is at opposition at 20:00
Jean-Dominique Maraldi discovered the globular cluster M15 on September 7, 1746. On September 11, 1746, Jean-Dominique Maraldi discovered the globular cluster M2. Nicolas-Louis de Lacaille discovered NGC 104 (47 Tucanae), the second largest and brightest globular cluster, on September 14th, 1751. William Herschel discovered the barred spiral galaxy NGC 7753 on September 12, 1784. William Herschel discovered the Saturnian satellite Mimas on September 17, 1789. Comet C/1793 S2 (Messier) was discovered by Charles Messier on September 27th, 1793. Karl Harding discovered asteroid 3 Juno on September 1, 1804. Neptune was discovered by Johann Gottfried Galle on September 23, 1846, using Urbain Le Verrier’s calculations of its position. On September 19, 1848, William Bond discovered Saturn’s fourteenth-magnitude satellite Hyperion, the first irregular moon to be discovered. On September 13, 1850, John Russell Hind discovered the asteroid 12 Victoria. E. E. Barnard discovered Jupiter’s fifth satellite, fourteenth-magnitude Amalthea, using the 36-inch refractor at the Lick Observatory, on September 9, 1892.
Only very minor meteor showers occur this month.
Information on passes of the ISS, the USAF’s X-37B, the HST, Starlink, and other satellites can be found at www.heavens-above.com/
The Moon is 4.5 days old, is illuminated 20.2%, subtends 31.3 arc minutes, and is located in Virgo on September 1st at 00:00 UT. The Moon is at its greatest northern declination on September 19th (+27.3 degrees) and its greatest southern declination on September 6th (-27.1 degrees). Longitudinal libration is at a maximum of +6.4 degrees on September 13th and a minimum of -5.3 degrees on September 1st and -4.5 degrees on September 27th. Latitudinal libration is at a maximum of +6.6 degrees on September 8th and a minimum of -6.7 degrees on September 22nd. Favorable librations for the following lunar features occur on the indicated dates: Crater Byrd on September 8th, Crater Cusanus on September 9th, Mare Humboldtianum on September 10th, and Crater Bailly on September 22nd. Full Moon occurs on September 10th. New Moon (i.e., the dark of the Moon) occurs on September 25th. The Moon passes near the first-magnitude star Antares (Alpha Scorpii) at 17:00 on September 3rd, the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 22:00 on September 15th, the first-magnitude star Aldebaran (Alpha Tauri) at 16:00 on September 16th, the bright open cluster M35 in Gemini at 13:00 on September 18th, the first-magnitude star Castor (Alpha Geminorum) at 3:00 on September 20th, the first-magnitude star Pollux (Beta Geminorum) at 8:00 on September 20th, the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 13:00 on September 21st, the first-magnitude star Regulus (Alpha Leonis) at 9:00 on September 23rd, the first-magnitude star Spica (Alpha Virginis) at 14:00 on September 27th, and the first-magnitude star Antares (Alpha Scorpii) again at 23:00 on September 30th. Browse www.lunar-occultations.com/iota/iotandx.htm for information on lunar occultation events. Visit saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons and curtrenz.com/moon.html for Full Moon and other lunar data. Browse skyandtelescope.org/wp-content/uploads/MoonMap.pdf and nightsky.jpl.nasa.gov/docs/ObserveMoon.pdf for simple lunar maps. Click on astrostrona.pl/moon-map for an excellent online lunar map. Visit www.ap-i.net/avl/en/start to download the free Virtual Moon Atlas. Consult time.unitarium.com/moon/where.html for current information on the Moon and www.fourmilab.ch/earthview/lunarform/lunarform.html for information on various lunar features. See svs.gsfc.nasa.gov/4874 for a lunar phase and libration calculator and quickmap.lroc.asu.edu/?extent=-90,-25.2362636,90,25.2362636&proj=10&layers=NrBsFYBoAZIRnpEoAsjYIHYFcA2vIBvAXwF1SizSg for the Lunar Reconnaissance Orbiter Camera (LROC) Quickmap. Click on www.calendar-12.com/moon_calendar/2022/september 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 www.lunar-occultations.com/rlo/rays/rays.htm
The zodiacal light, or the false dawn, is visible about two hours before sunrise from a dark site for two weeks beginning on September 23rd. It can be seen in Leo, Cancer, Gemini, and Taurus. Articles on the zodiacal light appear at www.atoptics.co.uk/highsky/zod1.htm and oneminuteastronomer.com/6645/zodiacal-light/
The Sun is located in Leo on September 1st. It enters Virgo on September 16th. The Sun crosses the celestial equator from north to south at 1:04 UT on September 23rd (9:04 p.m. EDT on September 22nd), the date of the northern hemisphere 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 +0.3, 7.8", 46% illuminated, 0.86 a.u., Virgo), Venus (magnitude -3.9., 10.1", 97% illuminated, 1.66 a.u., Virgo), Mars (magnitude -0.1, 9.8", 85% illuminated, 0.96 a.u., Leo), Jupiter (magnitude -2.9, 48.7", 100% illuminated, 4.05 a.u., Capricornus), Saturn (magnitude +0.3, 18.7", 100% illuminated, 8.90 a.u., Capricornus), Uranus (magnitude +5.7, 3.7", 100% illuminated, 19.10 a.u. on September 16th, Aries), Neptune (magnitude +7.8, 2.4", 100% illuminated, 28.91 a.u. on September 16th, Aquarius), and Pluto (magnitude +14.3, 0.1", 100% illuminated, 34.05 a.u. on September 16th, Sagittarius).
During the month of September, Jupiter and Neptune are located in the east, Saturn is located in the southeast, and Mercury is located in the west, in the evening. At midnight, Mars and Uranus can be found in the east, Jupiter in the southeast, and Saturn and Neptune in the south. Venus is in the east, Mars is in the south, Uranus is in the southwest, and Jupiter and Neptune are in the west in the morning sky.
Mercury is not well-placed for northern hemisphere observers this month. The speediest planet is stationary on September 9th and is at its greatest heliocentric latitude south on September 13th. It reaches inferior conjunction on September 23rd.
Venus is at perihelion on September 4th. It passes less than one degree north of Regulus on September 5th and reaches greatest heliocentric latitude north on September 26th. The brightest planet can be seen during bright early morning twilight early in September. However, its elongation from the Sun drops to ten degrees by September 15th and to six degrees by the end of the month. A waning crescent Moon lies nine degrees from Venus on September 24th.
Mars brightens from magnitude -0.1 to magnitude -0.6 and increases in apparent size from 9.8 to 10.7 arc seconds during September. The following Martian surface features are well-placed not long after midnight: the Tharsis Ridge on September 1st, Valles Marineris on September 8th, Hellas Basin and Syrtis Major on September 14th, Mare Cimmerium and Syrtis Major on September 22nd, and Mare Sirenum on September 30th. The apparent diameter of Mars exceeds 10 arc seconds on September 4th. The Red Planet passes approximately four degrees north of Aldebaran on September 9th UT. The Last Quarter Moon passes four degrees to the north of Mars on September 17th. The apparent brightness of Mars exceeds magnitude -0.5 on September 26th.
Jupiter shines at magnitude -2.9, subtends 49.9 arc seconds, is 33 light minutes from the Earth, and lies within one arc minute of the celestial equator when it reaches opposition on September 26th. This will be the closest opposition since October 8,1963. Jupiter’s retrograde motion is at a maximum and the Galilean satellites are at their brightest and widest apparent separation at opposition. At opposition transits of the satellites and their shadows occur almost simultaneously. The shadows precede the satellites prior to opposition and follow them after opposition. Callisto lies due south of Jupiter on the night of September 4th/5th. The just past Full gibbous Moon passes less than two degrees south of the Jupiter on September 11th. An article on observing Jupiter can be found on pages 48 and 49 of the September 2022 issue of Sky & Telescope. Information on Great Red Spot transit times and Galilean satellite events is available on pages 50 and 51 of the September 2022 issue of Sky & Telescope and online at www.skyandtelescope.com/observing/interactive-sky-watching-tools/ and shallowsky.com/jupiter/
This month Saturn fades from magnitude +0.3 to magnitude +0.5 and shrinks in apparent size from 18.7 arc seconds to 18.1 arc seconds. The apparent tilt of the gas giant planet’s rings increases to 15 degrees by September’s end. Saturn is approximately 20 degrees in altitude by 9:00 p.m. local daylight time early in the month. The waxing gibbous Moon passes four degrees south of the Ringed Planet on September 8th. See pages 46 to 51 of the September 2022 issue of Astronomy for an article on Saturn. Titan, Saturn’s largest and brightest satellite, shines at magnitude +8.5. Titan is due north of the planet on September 6th and September 22nd and due south of it on September 14th and September 30th. The odd satellite Iapetus shines at twelfth magnitude when it is reaches eastern elongation on September 15th. It is almost nine are minutes east of Saturn at that time. For further information on Saturn’s satellites, browse www.skyandtelescope.com/observing/interactive-sky-watching-tools/
Uranus lies in the middle of a triangle of sixth-magnitude stars, one of which is 43 Arietis, this month. The waning gibbous Moon passes less than one degree north of Uranus and occults it from some locations on September 14th. Visit www.nakedeyeplanets.com/uranus.htm for a finder chart. Five of the brightest Uranian satellites (Miranda, Ariel, Umbriel, Titania, and Oberon) can be located using the Sky & Telescope interactive observing tool at skyandtelescope.org/observing/interactive-sky-watching-tools/the-elusive-moons-ofuranus/
Neptune is located almost five degrees east of the fourth-magnitude star Phi Aquarii as September begins. The ice giant planet lies less than four degrees east of the star at the end of the month. It passes within 1.5 arc minutes of a sixth-magnitude star on September 23rd. Neptune subtends 2.4 arc seconds, shines at magnitude +7.8, and lies at a distance of 4.0 light hours when it reaches opposition on September 16th. See www.nakedeyeplanets.com/neptune.htm for an online finder chart. A finder chart for Neptune appears on page 49 of the September 2022 issue of Sky & Telescope. Triton, Neptune's brightest satellite, can be located using the Sky & Telescope interactive observing tool at skyandtelescope.org/observing/interactive-sky-watching-tools/sky-telescopes-triton-tracker/
Pluto is located low in eastern Sagittarius. Finder charts are available at pages 48 and 49 of the July 2022 issue of Sky & Telescope and on page 239 of the RASC Observer’s Handbook 2022.
For more on the planets and how to locate them, see www.nakedeyeplanets.com/
The Distance, Brightness, and Apparent Size of Planets graphic at www.timeanddate.com/astronomy/planets/distance displays the apparent and comparative sizes of the planets, along with their magnitudes and distances, on a given date and time.
Comet C/2017 K2 (PanSTARRS) continues to head southward through Scorpius and into Lupus. It passes just to the west of Rho Scorpii on September 19th and September 20th. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html and cobs.si/ for additional information on comets visible this month.
Asteroid 4 Vesta shines at sixth-magnitude as it travels southwestward through Aquarius and into Capricornus. Asteroid 3 Juno shines at magnitude +7.8 when it reaches opposition in Aquarius on September 7th. The twelfth-largest asteroid lies with one degree of the fourth-magnitude star Lambda Aquarii from September 20th to September 24th. A finder chart appears on page 49 of the September 2022 issue of Sky & Telescope. Other asteroids brighter than magnitude +11.0 that reach opposition this month include 216 Kleopatra (magnitude +9.9) in Pegasus on September 11th and 128 Nemesis (magnitude +10.8) in Aquarius on September 17th. Data on asteroid occultations taking place this month is available at www.asteroidoccultation.com/2022_09_si.htm and www.poyntsource.com/New/Global.htm
A wealth of current information on solar system celestial bodies is posted at nineplanets.org/ and www.curtrenz.com/astronomy.html
Information on the celestial events transpiring each week can be found at stardate.org/nightsky and astronomy.com/skythisweek and www.skyandtelescope.com/observing/sky-at-a-glance/
An online data generator for various astronomical events is available at astronomynow.com/almanac/
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in brightness from magnitude +2.1 to magnitude +3.4, on September 2nd, 5th, 8th, 11th, 14th, 17th, 20th, 22nd, 25th, and 28th. Consult skyandtelescope.org/observing/the-minima-of-algol/ or page 50 of the September 2022 issue of Sky & Telescope for the minima times. On the morning of September 15th, Algol shines at minimum brightness (magnitude +3.4) for approximately two hours centered at 12:42 a.m. EDT (4:42 UT September 15th). It does the same at 9:31 p.m. EDT (1:31 UT September 18th) on the night of September 17th. For more on Algol, see stars.astro.illinois.edu/sow/Algol.html and www.solstation.com/stars2/algol3.htm
Free star maps for this month can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart and www.whatsouttonight.com/
Weather and observing conditions forecasts are available at www.cleardarksky.com/csk/index.html
Data on current supernovae can be found at www.rochesterastronomy.org/snimages/
Finder charts for the Messier objects and other deep-sky objects are posted at freestarcharts.com/messier and freestarcharts.com/ngc-ic and www.cambridge.org/turnleft/seasonal_skies_july-september
Telrad finder charts for the Messier Catalog are posted at www.custerobservatory.org/docs/messier2.pdf and www.star-shine.ch/astro/messiercharts/messierTelrad.htm
Telrad finder charts for the SAC’s 110 Best of the NGC are available at sao64.free.fr/observations/catalogues/cataloguesac.pdf
Information pertaining to observing some of the more prominent Messier galaxies can be found at www.cloudynights.com/topic/358295-how-to-locate-some-of-the-major-messier-galaxies-and-helpful-advice-for-novice-amateur-astronomers/
Freeware sky atlases can be downloaded at www.deepskywatch.com/files/deepsky-atlas/Deep-Sky-Hunter-atlas-full.pdf and www.cloudynights.com/articles/cat/articles/observing-skills/free-mag-7-star-charts-r1021 and allans-stuff.com/triatlas/
Author Phil Harrington offers an excellent freeware planetarium program for binocular observers known as TUBA (Touring the Universe through Binoculars Atlas), which also includes information on purchasing binoculars, at www.philharrington.net/tuba.htm
Stellarium and Cartes du Ciel are two excellent freeware planetarium programs that are available at stellarium.org/ and www.ap-i.net/skychart/en/start
Deep-sky object list generators can be found at www.virtualcolony.com/sac/ and telescopius.com/?fromdsobrowser and www.tonightssky.com/MainPage.php
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
Fifty 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 6946, NGC 6951, NGC 7023, NGC 7160, NGC 7142 (Cepheus); B343, B361, Ba6, Be87, Cr 421, Do9, IC 4996, M29, M39, NGC 6866, NGC 6871, NGC 6888, NGC 6894, NGC 6910, NGC 6960, NGC 6992, NGC 6994, NGC 6995, NGC 7000, NGC 7008, NGC 7026, NGC 7027, NGC 7039, NGC 7048, 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.