Post by Dave Mitsky on Aug 16, 2022 4:18:41 GMT
August Celestial Calendar by Dave Mitsky
All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)
8/1 Mars is 1.4 degrees south of Uranus at 9:00
8/2 Venus is at the ascending node today
8/4 Mercury is 0.7 degrees north of the first-magnitude star Regulus (Alpha Leonis) at 5:00; 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 19:53
8/5 First Quarter Moon occurs at 11:07
8/9 A double Galilean shadow transit involving Io and Ganymede begins at 1:30
8/10 The Moon is at perigee, subtending 33' 13'' from a distance of 359,830 kilometers (223,587 miles), at 17:09
8/12 Full Moon (known as the Fruit, Grain, Green Corn, or Sturgeon Moon) occurs at 1:36; the Moon is 4 degrees south of Saturn at 4:00
8/13 Mercury is at the descending node today; the peak of the Perseid meteor shower (a zenithal hourly rate of 100 or more per hour) is predicted to occur at 1:00
8/14 The Moon is 3 degrees south of Neptune at 10:00; Saturn (magnitude +0.3, 18.8") is at opposition at 17:00
8/15 The Moon is 1.9 degrees south of Jupiter at 10:00
8/16 A double Galilean shadow transit involving Io and Ganymede begins at 3:59
8/18 The Moon is 0.6 degrees south of Uranus, with an occultation taking place in Iceland, Greenland, Canada, the northern portion of the contiguous United States, Alaska, most of Hawaii, and Micronesia, at 15:00
8/19 Last Quarter Moon occurs at 4:36; the Moon is 3 degrees north of Mars at 12:00
8/20 The Curtiss Cross, an X-shaped clair-obscur illumination effect located between the craters Parry and Gambart, is predicted to be visible at 18:57
8/22 Asteroid 4 Vesta (magnitude +6.0) is at opposition in Aquarius at 19:00; the Moon is at apogee, subtending 29' 28" at a distance of 405,417 kilometers (251,915 miles) at 21:52
8/23 Mercury is at aphelion today
8/24 Uranus is stationary at 15:00
8/25 The Moon is 0.7 degrees south of the dwarf planet/asteroid 1 Ceres, with an occultation taking place in southernmost South America and most of southern and eastern Polynesia, at 19:00; the Moon is 4 degrees north of Venus at 21:00
8/27 New Moon (lunation 1233) occurs at 8:17; Mercury is at greatest eastern elongation (27 degrees) at 16:00
The gibbous phase of Mars was first observed by Francesco Fontana on August 24, 1638. Abraham Ihle discovered the globular cluster M22 on August 26, 1665. Nicolas Sarabat discovered Comet C/1729 P1 (Sarabat) on August 1, 1729. Caroline Herschel discovered Comet C/1786 P1 (Herschel) on August 1, 1786. The Saturnian satellite Enceladus was discovered by William Herschel on August 28, 1789. Dominique Dumouchel was the first person to observe the return of Comet 1P/Halley on August 5, 1835. John Russell Hind discovered asteroid 7 Iris on August 13, 1847. Asaph Hall discovered Deimos on August 11, 1877 and Phobos on August 17, 1877. The first extragalactic supernova, S Andromedae, was discovered by Ernst Hartwig on August 20, 1885. David Jewitt and Jane Luu discovered the trans-Neptunian object (15760) 1992 QB1 on August 30, 1992. The Jovian satellite 2002 Laomedeia was discovered by Matthew Holman on August 13th, 2002.
The peak of the Perseid meteor shower takes place on the night of August 12th/August 13th but is severely compromised by moonlight. The periodic comet 109P/Swift-Tuttle is the source of Perseid meteors. The shower’s radiant lies just to the southeast of the Double Cluster (NGC 869 and NGC 884). For more on this year’s Perseids, see page 50 of the August 2022 issue of Sky & Telescope or click on earthsky.org/astronomy-essentials/everything-you-need-to-know-perseid-meteor-shower/
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 3.1 days old, is illuminated 9.0%, subtends 30.2 arc minutes, and is located in Leo on August 1st at 00:00 UT. The Moon is at its greatest northern declination on August 23rd (+27.0 degrees) and its greatest southern declination on August 9th (-27.0 degrees). Longitudinal libration is at a maximum of +7.3 degrees on August 16th and a minimum of -6.6 degrees on August 4th. Latitudinal libration is at a maximum of +6.5 degrees on August 12th and a minimum of -6.6 degrees on August 26th. Favorable librations for the following lunar features occur on the indicated dates: Crater Poncelet on August 10th, Crater Da Sitter on August 11th, Crater Hayn F on August 12th, and Crater Hausen on August 26th. The Moon is at perigee on August 10th and at apogee on August 22nd. Full Moon occurs on August 12th. New Moon (i.e., the dark of the Moon) occurs on August 27th. The Moon passes near the first-magnitude star Spica (Alpha Virginis) at 2:00 UT on August 4th, the first first-magnitude star Antares (Alpha Scorpii) at 11:00 UT on August 7th, the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 14:00 UT on August 19th, the first-magnitude star Aldebaran (Alpha Tauri) at 8:00 UT on August 20th, the bright open cluster M35 in Gemini at 6:00 UT on August 22nd, the first-magnitude star Castor (Alpha Geminorum) at 19:00 UT on August 23rd, the first-magnitude star Pollux (Beta Geminorum) at 1:00 UT on August 24th, the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 5:00 UT on August 25th, and the first-magnitude star Spica (Alpha Virginis) again at 8:00 UT on August 31st. The Moon occults Uranus on August 18th and the dwarf planet/asteroid 1 Ceres on August 25th from certain parts of the world. 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/august 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 Sun is located in Cancer on August 1st. It enters the constellation of Leo on August 10th.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on August 1: Mercury (magnitude -0.6, 5.3", 86% illuminated, 1.27 a.u., Leo), Venus (magnitude -3.8, 10.7", 93% illuminated, 1.56 a.u., Gemini), Mars (magnitude +0.2, 8.3", 85% illuminated, 1.13 a.u., Aries), Jupiter (magnitude -2.7, 45.1", 99% illuminated, 4.37 a.u., Cetus), Saturn (magnitude +0.4, 18.7", 100% illuminated, 8.89 a.u., Capricornus), Uranus (magnitude +5.7, 3.6", 100% illuminated, 19.59 a.u. on August 16th, Aries), Neptune (magnitude +7.8, 2.4", 100% illuminated, 29.05 a.u. on August 16th, Pisces), and Pluto (magnitude +14.3, 0.1", 100% illuminated, 33.68 a.u. on August 16th, Sagittarius).
This month Mercury is located in the west during the evening. At midnight, Mars, Jupiter, and Uranus can be found in the east, Saturn in the south, and Neptune in the southeast. Venus is in the east, Mars and Uranus are in the southeast, Jupiter is in the south, and Saturn and Neptune are in the southwest in the morning sky.
Mercury passes less than one degree north of Regulus on August 4th. The speediest planet will be at the descending node on August 13th, at aphelion on August 23rd, and at greatest eastern elongation on August 27th. This will be a poor evening apparition for mid-northern hemisphere observers but the best one of the year for those in the southern hemisphere.
During August, brilliant Venus changes very little in brightness and decreases in angular size from 10.7 to 10.1 arc seconds, while it increases in illumination from 93% to 97%. Venus is at the ascending node on August 2nd. It departs Gemini and enters Cancer on August and is a bit less than one degree west of M44 (the Beehive Cluster) on August 17th. The brightest planet grows closer and closer to the Sun during August, decreasing in solar elongation to 14 degrees by the end of the month. The waning crescent Moon passes four degrees to the north of Venus on August 25th.
Mars and Uranus are in conjunction on August 1st. Mars exits Aries and enters Taurus on August 9th. The Last Quarter Moon passes three degrees north of Mars on August 19th. On that date, the Moon is situated between Mars and M45 (the Pleiades). The Red Planet is at western quadrature, or 90 degrees west of the Sun, on August 27th. It lies between M45 (the Pleiades) and Melotte 25 (the Hyades) from August 29th to August 31st. As August comes to an end, Mars has brightened to magnitude -0.1 and increased in angular diameter to 9.7 arc seconds
Jupiter lies in the uppermost part of northwestern Cetus this month. It rises shortly before 9:00 p.m. local time by August 31st. Jupiter shines at magnitude -2.9 and subtends 48.6 arc seconds on that date. The waning gibbous Moon passes two degrees to the south of Jupiter on August 15th. Double Galilean satellite shadow transits occur on August 9th and August 16th UT. An article on the August 16th UT event can be found on page 49 of the August 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 August 2022 issue of Sky & Telescope.
When Saturn reaches opposition on August 14th, it lies 15.5 degrees south of the celestial equator and 74 light minutes from the Earth. The planet's disk subtends 18.8 arc seconds at that time and its rings span 43.7 arc seconds and are inclined by 13 degrees. The Full Moon passes four degrees to the south of Saturn on August 12th. Titan (magnitude 8.5) is positioned north of the Ringed Planet on August 5th and August 21st and south of it on August 13th and August 29th. Saturn's odd satellite Iapetus shines at 10th magnitude as it reaches western elongation nine arc minutes west of the planet on August 7th. It reaches superior conjunction on August 27th. For information on Saturn’s satellites, browse skyandtelescope.org/observing/interactive-sky-watching-tools/saturns-moons-javascript-utility/
Uranus is in conjunction with Mars on August 1st, with Mars passing 1.4 degrees north of the gas giant planet. The waning gibbous Moon passes less than a degree north of Uranus on August 18th and occults the planet in some parts of the world. Uranus reaches its first stationary point on August 24th and subsequently begins retrograde or western motion. Visit www.nakedeyeplanets.com/uranus.htm for a finder chart. The positions of the planet's brightest satellites can be determined using the interactive observing tool at skyandtelescope.org/observing/interactive-sky-watching-tools/the-elusive-moons-ofuranus/
Neptune is located five degrees due south of the fourth-magnitude star Phi Aquarii. The gas giant planet is at western quadrature on August 11th. The waning gibbous Moon passes three degrees south of Neptune on August 14th. Browse www.nakedeyeplanets.com/neptune.htm for a finder chart. Triton, Neptune's brightest satellite, can be located using the interactive observing tool at skyandtelescope.org/observing/interactive-sky-watching-tools/sky-telescopes-triton-tracker/
The dwarf planet Pluto is positioned low in eastern Sagittarius, about 4.5 degrees west of the globular cluster M75. Finder charts can be found 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/
Comet C/2017 K2 (PanSTARRS) departs Ophiuchus and heads southwestward into Scorpius during August. It passes about 2.5 degrees northwest of the eighth-magnitude globular cluster M107 in Ophiuchus on August 2nd and approximately four degrees west of the seventh-magnitude globular cluster M80 in Scorpius as August ends. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html and cobs.si/ for information on this and other comets visible this month.
Asteroid 4 Vesta shines at sixth magnitude as it travels southwestward through Aquarius this month, passing less than two degrees north of NGC 7293 (the Helix Nebula) on the nights of August 14th-16th. It reaches opposition on August 22th. A finder chart can be found on page 49 of the August issue of Sky & Telescope. The main-belt asteroid 704 Interamnia travels slightly northwestward through Pegasus and Equuleus. It shines at magnitude +10.2 and is located in Equuleus at opposition on August 18th. This asteroid has a high orbital inclination of 17 degrees. Asteroid 198 Apella achieves a brightness of magnitude +10.6 when it comes to opposition in Aquarius on August 5th. For information on asteroid occultations taking place this month, see www.asteroidoccultation.com/2022_08_si.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/
Data on current supernovae can be found at www.rochesterastronomy.org/snimages/
Free star maps for August can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart and www.kenpress.com/index.html
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
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/
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/
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/ and tonightssky.com/MainPage.php
Sixty binary and multiple stars for August: 5 Aquilae, Struve 2404, 11 Aquilae, Struve 2426, 15 Aquilae, Struve 2449, 23 Aquilae, Struve 2532, Pi Aquilae, 57 Aquilae (Aquila); Beta Cygni (Albireo), 16 Cygni, Delta Cygni, 17 Cygni (Cygnus); 41 & 40 Draconis, 39 Draconis, Struve 2348, Sigma Draconis, Struve 2573, Epsilon Draconis (Draco); 95 Herculis, 100 Herculis, Struve 2289, Struve 2411 (Hercules); Struve 2349, Struve 2372, Epsilon-1 & Epsilon-2 Lyrae (the Double-Double), Zeta-2 Lyrae, Beta Lyrae, Otto Struve 525, Struve 2470 & Struve 2474 (the Other Double-Double) (Lyra); 67 Ophiuchi, 69 Ophiuchi, 70 Ophiuchi, Struve 2276, 74 Ophiuchi (Ophiuchus); Mu Sagittarii, Eta Sagittarii, 21 Sagittarii, Zeta Sagittarii, H N 119, 52 Sagittarii, 54 Sagittarii (Sagittarius); Struve 2306, Delta Scuti, Struve 2373 (Scutum); Struve 2296, Struve 2303, 59 Serpentis, Theta Serpentis (Serpens Cauda); Struve 2445, Struve 2455, Struve 2457, 4 Vupeculae, Struve 2521, Struve 2523, Struve 2540, Struve 2586, Otto Struve 388, Struve 2599 (Vulpecula)
Notable carbon star for August: V Aquilae
Eighty deep-sky objects for August: B139, B142, B143, NGC 6709, NGC 6738, NGC 6741, NGC 6751, NGC 6755, NGC 6772, NGC 6778, NGC 6781, NGC 6804, PK64+5.1 (Aquila); NGC 6819, NGC 6826, NGC 6834, (Cygnus); NGC 6643, NGC 6742 (Draco); DoDz 9 (Hercules); M56, M57, NGC 6703, NGC 6791, Ste1 (Lyra); NGC 6572, NGC 6633 (Ophiuchus); H20, M71 (Sagitta); B86, B87, B90, B92, B93, M8, M17, M18, M20, M21, M22, M23, M24, M25, M28, M54, M55, M69, M70, M75, NGC 6520, NGC 6544, NGC 6546, NGC 6553, NGC 6565, NGC 6603, NGC 6818, NGC 6822 (Sagittarius); IC 4703, IC 4756, M16, NGC 6604 (Serpens Cauda); B100, B101, B103, B104, B110, B111, B113, Bas 1, IC 1295, M11, M26, NGC 6649, NGC 6712 (Scutum); Cr 399 (asterism), M27, NGC 6802, NGC 6823, NGC 6834, NGC 6940, St 1 (Vulpecula)
Top ten binocular deep-sky objects for August: Cr 399, IC 4756, M8, M11, M17, M22, M24, M25, M27, NGC 6633 (IC 4756 and NGC 6633 are collectively known as the Binocular Double Cluster)
Top ten deep-sky objects for August: M8, M11, M16, M17, M20, M22, M24, M27, M55, M57
Challenge deep-sky object for August: Abell 53 (Aquila)
The objects listed above are located between 18:00 and 20:00 hours of right ascension.
All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)
8/1 Mars is 1.4 degrees south of Uranus at 9:00
8/2 Venus is at the ascending node today
8/4 Mercury is 0.7 degrees north of the first-magnitude star Regulus (Alpha Leonis) at 5:00; 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 19:53
8/5 First Quarter Moon occurs at 11:07
8/9 A double Galilean shadow transit involving Io and Ganymede begins at 1:30
8/10 The Moon is at perigee, subtending 33' 13'' from a distance of 359,830 kilometers (223,587 miles), at 17:09
8/12 Full Moon (known as the Fruit, Grain, Green Corn, or Sturgeon Moon) occurs at 1:36; the Moon is 4 degrees south of Saturn at 4:00
8/13 Mercury is at the descending node today; the peak of the Perseid meteor shower (a zenithal hourly rate of 100 or more per hour) is predicted to occur at 1:00
8/14 The Moon is 3 degrees south of Neptune at 10:00; Saturn (magnitude +0.3, 18.8") is at opposition at 17:00
8/15 The Moon is 1.9 degrees south of Jupiter at 10:00
8/16 A double Galilean shadow transit involving Io and Ganymede begins at 3:59
8/18 The Moon is 0.6 degrees south of Uranus, with an occultation taking place in Iceland, Greenland, Canada, the northern portion of the contiguous United States, Alaska, most of Hawaii, and Micronesia, at 15:00
8/19 Last Quarter Moon occurs at 4:36; the Moon is 3 degrees north of Mars at 12:00
8/20 The Curtiss Cross, an X-shaped clair-obscur illumination effect located between the craters Parry and Gambart, is predicted to be visible at 18:57
8/22 Asteroid 4 Vesta (magnitude +6.0) is at opposition in Aquarius at 19:00; the Moon is at apogee, subtending 29' 28" at a distance of 405,417 kilometers (251,915 miles) at 21:52
8/23 Mercury is at aphelion today
8/24 Uranus is stationary at 15:00
8/25 The Moon is 0.7 degrees south of the dwarf planet/asteroid 1 Ceres, with an occultation taking place in southernmost South America and most of southern and eastern Polynesia, at 19:00; the Moon is 4 degrees north of Venus at 21:00
8/27 New Moon (lunation 1233) occurs at 8:17; Mercury is at greatest eastern elongation (27 degrees) at 16:00
The gibbous phase of Mars was first observed by Francesco Fontana on August 24, 1638. Abraham Ihle discovered the globular cluster M22 on August 26, 1665. Nicolas Sarabat discovered Comet C/1729 P1 (Sarabat) on August 1, 1729. Caroline Herschel discovered Comet C/1786 P1 (Herschel) on August 1, 1786. The Saturnian satellite Enceladus was discovered by William Herschel on August 28, 1789. Dominique Dumouchel was the first person to observe the return of Comet 1P/Halley on August 5, 1835. John Russell Hind discovered asteroid 7 Iris on August 13, 1847. Asaph Hall discovered Deimos on August 11, 1877 and Phobos on August 17, 1877. The first extragalactic supernova, S Andromedae, was discovered by Ernst Hartwig on August 20, 1885. David Jewitt and Jane Luu discovered the trans-Neptunian object (15760) 1992 QB1 on August 30, 1992. The Jovian satellite 2002 Laomedeia was discovered by Matthew Holman on August 13th, 2002.
The peak of the Perseid meteor shower takes place on the night of August 12th/August 13th but is severely compromised by moonlight. The periodic comet 109P/Swift-Tuttle is the source of Perseid meteors. The shower’s radiant lies just to the southeast of the Double Cluster (NGC 869 and NGC 884). For more on this year’s Perseids, see page 50 of the August 2022 issue of Sky & Telescope or click on earthsky.org/astronomy-essentials/everything-you-need-to-know-perseid-meteor-shower/
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 3.1 days old, is illuminated 9.0%, subtends 30.2 arc minutes, and is located in Leo on August 1st at 00:00 UT. The Moon is at its greatest northern declination on August 23rd (+27.0 degrees) and its greatest southern declination on August 9th (-27.0 degrees). Longitudinal libration is at a maximum of +7.3 degrees on August 16th and a minimum of -6.6 degrees on August 4th. Latitudinal libration is at a maximum of +6.5 degrees on August 12th and a minimum of -6.6 degrees on August 26th. Favorable librations for the following lunar features occur on the indicated dates: Crater Poncelet on August 10th, Crater Da Sitter on August 11th, Crater Hayn F on August 12th, and Crater Hausen on August 26th. The Moon is at perigee on August 10th and at apogee on August 22nd. Full Moon occurs on August 12th. New Moon (i.e., the dark of the Moon) occurs on August 27th. The Moon passes near the first-magnitude star Spica (Alpha Virginis) at 2:00 UT on August 4th, the first first-magnitude star Antares (Alpha Scorpii) at 11:00 UT on August 7th, the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 14:00 UT on August 19th, the first-magnitude star Aldebaran (Alpha Tauri) at 8:00 UT on August 20th, the bright open cluster M35 in Gemini at 6:00 UT on August 22nd, the first-magnitude star Castor (Alpha Geminorum) at 19:00 UT on August 23rd, the first-magnitude star Pollux (Beta Geminorum) at 1:00 UT on August 24th, the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 5:00 UT on August 25th, and the first-magnitude star Spica (Alpha Virginis) again at 8:00 UT on August 31st. The Moon occults Uranus on August 18th and the dwarf planet/asteroid 1 Ceres on August 25th from certain parts of the world. 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/august 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 Sun is located in Cancer on August 1st. It enters the constellation of Leo on August 10th.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on August 1: Mercury (magnitude -0.6, 5.3", 86% illuminated, 1.27 a.u., Leo), Venus (magnitude -3.8, 10.7", 93% illuminated, 1.56 a.u., Gemini), Mars (magnitude +0.2, 8.3", 85% illuminated, 1.13 a.u., Aries), Jupiter (magnitude -2.7, 45.1", 99% illuminated, 4.37 a.u., Cetus), Saturn (magnitude +0.4, 18.7", 100% illuminated, 8.89 a.u., Capricornus), Uranus (magnitude +5.7, 3.6", 100% illuminated, 19.59 a.u. on August 16th, Aries), Neptune (magnitude +7.8, 2.4", 100% illuminated, 29.05 a.u. on August 16th, Pisces), and Pluto (magnitude +14.3, 0.1", 100% illuminated, 33.68 a.u. on August 16th, Sagittarius).
This month Mercury is located in the west during the evening. At midnight, Mars, Jupiter, and Uranus can be found in the east, Saturn in the south, and Neptune in the southeast. Venus is in the east, Mars and Uranus are in the southeast, Jupiter is in the south, and Saturn and Neptune are in the southwest in the morning sky.
Mercury passes less than one degree north of Regulus on August 4th. The speediest planet will be at the descending node on August 13th, at aphelion on August 23rd, and at greatest eastern elongation on August 27th. This will be a poor evening apparition for mid-northern hemisphere observers but the best one of the year for those in the southern hemisphere.
During August, brilliant Venus changes very little in brightness and decreases in angular size from 10.7 to 10.1 arc seconds, while it increases in illumination from 93% to 97%. Venus is at the ascending node on August 2nd. It departs Gemini and enters Cancer on August and is a bit less than one degree west of M44 (the Beehive Cluster) on August 17th. The brightest planet grows closer and closer to the Sun during August, decreasing in solar elongation to 14 degrees by the end of the month. The waning crescent Moon passes four degrees to the north of Venus on August 25th.
Mars and Uranus are in conjunction on August 1st. Mars exits Aries and enters Taurus on August 9th. The Last Quarter Moon passes three degrees north of Mars on August 19th. On that date, the Moon is situated between Mars and M45 (the Pleiades). The Red Planet is at western quadrature, or 90 degrees west of the Sun, on August 27th. It lies between M45 (the Pleiades) and Melotte 25 (the Hyades) from August 29th to August 31st. As August comes to an end, Mars has brightened to magnitude -0.1 and increased in angular diameter to 9.7 arc seconds
Jupiter lies in the uppermost part of northwestern Cetus this month. It rises shortly before 9:00 p.m. local time by August 31st. Jupiter shines at magnitude -2.9 and subtends 48.6 arc seconds on that date. The waning gibbous Moon passes two degrees to the south of Jupiter on August 15th. Double Galilean satellite shadow transits occur on August 9th and August 16th UT. An article on the August 16th UT event can be found on page 49 of the August 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 August 2022 issue of Sky & Telescope.
When Saturn reaches opposition on August 14th, it lies 15.5 degrees south of the celestial equator and 74 light minutes from the Earth. The planet's disk subtends 18.8 arc seconds at that time and its rings span 43.7 arc seconds and are inclined by 13 degrees. The Full Moon passes four degrees to the south of Saturn on August 12th. Titan (magnitude 8.5) is positioned north of the Ringed Planet on August 5th and August 21st and south of it on August 13th and August 29th. Saturn's odd satellite Iapetus shines at 10th magnitude as it reaches western elongation nine arc minutes west of the planet on August 7th. It reaches superior conjunction on August 27th. For information on Saturn’s satellites, browse skyandtelescope.org/observing/interactive-sky-watching-tools/saturns-moons-javascript-utility/
Uranus is in conjunction with Mars on August 1st, with Mars passing 1.4 degrees north of the gas giant planet. The waning gibbous Moon passes less than a degree north of Uranus on August 18th and occults the planet in some parts of the world. Uranus reaches its first stationary point on August 24th and subsequently begins retrograde or western motion. Visit www.nakedeyeplanets.com/uranus.htm for a finder chart. The positions of the planet's brightest satellites can be determined using the interactive observing tool at skyandtelescope.org/observing/interactive-sky-watching-tools/the-elusive-moons-ofuranus/
Neptune is located five degrees due south of the fourth-magnitude star Phi Aquarii. The gas giant planet is at western quadrature on August 11th. The waning gibbous Moon passes three degrees south of Neptune on August 14th. Browse www.nakedeyeplanets.com/neptune.htm for a finder chart. Triton, Neptune's brightest satellite, can be located using the interactive observing tool at skyandtelescope.org/observing/interactive-sky-watching-tools/sky-telescopes-triton-tracker/
The dwarf planet Pluto is positioned low in eastern Sagittarius, about 4.5 degrees west of the globular cluster M75. Finder charts can be found 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/
Comet C/2017 K2 (PanSTARRS) departs Ophiuchus and heads southwestward into Scorpius during August. It passes about 2.5 degrees northwest of the eighth-magnitude globular cluster M107 in Ophiuchus on August 2nd and approximately four degrees west of the seventh-magnitude globular cluster M80 in Scorpius as August ends. Visit cometchasing.skyhound.com/ and www.aerith.net/comet/future-n.html and cobs.si/ for information on this and other comets visible this month.
Asteroid 4 Vesta shines at sixth magnitude as it travels southwestward through Aquarius this month, passing less than two degrees north of NGC 7293 (the Helix Nebula) on the nights of August 14th-16th. It reaches opposition on August 22th. A finder chart can be found on page 49 of the August issue of Sky & Telescope. The main-belt asteroid 704 Interamnia travels slightly northwestward through Pegasus and Equuleus. It shines at magnitude +10.2 and is located in Equuleus at opposition on August 18th. This asteroid has a high orbital inclination of 17 degrees. Asteroid 198 Apella achieves a brightness of magnitude +10.6 when it comes to opposition in Aquarius on August 5th. For information on asteroid occultations taking place this month, see www.asteroidoccultation.com/2022_08_si.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/
Data on current supernovae can be found at www.rochesterastronomy.org/snimages/
Free star maps for August can be downloaded at www.skymaps.com/downloads.html and www.telescope.com/content.jsp?pageName=Monthly-Star-Chart and www.kenpress.com/index.html
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
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/
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/
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/ and tonightssky.com/MainPage.php
Sixty binary and multiple stars for August: 5 Aquilae, Struve 2404, 11 Aquilae, Struve 2426, 15 Aquilae, Struve 2449, 23 Aquilae, Struve 2532, Pi Aquilae, 57 Aquilae (Aquila); Beta Cygni (Albireo), 16 Cygni, Delta Cygni, 17 Cygni (Cygnus); 41 & 40 Draconis, 39 Draconis, Struve 2348, Sigma Draconis, Struve 2573, Epsilon Draconis (Draco); 95 Herculis, 100 Herculis, Struve 2289, Struve 2411 (Hercules); Struve 2349, Struve 2372, Epsilon-1 & Epsilon-2 Lyrae (the Double-Double), Zeta-2 Lyrae, Beta Lyrae, Otto Struve 525, Struve 2470 & Struve 2474 (the Other Double-Double) (Lyra); 67 Ophiuchi, 69 Ophiuchi, 70 Ophiuchi, Struve 2276, 74 Ophiuchi (Ophiuchus); Mu Sagittarii, Eta Sagittarii, 21 Sagittarii, Zeta Sagittarii, H N 119, 52 Sagittarii, 54 Sagittarii (Sagittarius); Struve 2306, Delta Scuti, Struve 2373 (Scutum); Struve 2296, Struve 2303, 59 Serpentis, Theta Serpentis (Serpens Cauda); Struve 2445, Struve 2455, Struve 2457, 4 Vupeculae, Struve 2521, Struve 2523, Struve 2540, Struve 2586, Otto Struve 388, Struve 2599 (Vulpecula)
Notable carbon star for August: V Aquilae
Eighty deep-sky objects for August: B139, B142, B143, NGC 6709, NGC 6738, NGC 6741, NGC 6751, NGC 6755, NGC 6772, NGC 6778, NGC 6781, NGC 6804, PK64+5.1 (Aquila); NGC 6819, NGC 6826, NGC 6834, (Cygnus); NGC 6643, NGC 6742 (Draco); DoDz 9 (Hercules); M56, M57, NGC 6703, NGC 6791, Ste1 (Lyra); NGC 6572, NGC 6633 (Ophiuchus); H20, M71 (Sagitta); B86, B87, B90, B92, B93, M8, M17, M18, M20, M21, M22, M23, M24, M25, M28, M54, M55, M69, M70, M75, NGC 6520, NGC 6544, NGC 6546, NGC 6553, NGC 6565, NGC 6603, NGC 6818, NGC 6822 (Sagittarius); IC 4703, IC 4756, M16, NGC 6604 (Serpens Cauda); B100, B101, B103, B104, B110, B111, B113, Bas 1, IC 1295, M11, M26, NGC 6649, NGC 6712 (Scutum); Cr 399 (asterism), M27, NGC 6802, NGC 6823, NGC 6834, NGC 6940, St 1 (Vulpecula)
Top ten binocular deep-sky objects for August: Cr 399, IC 4756, M8, M11, M17, M22, M24, M25, M27, NGC 6633 (IC 4756 and NGC 6633 are collectively known as the Binocular Double Cluster)
Top ten deep-sky objects for August: M8, M11, M16, M17, M20, M22, M24, M27, M55, M57
Challenge deep-sky object for August: Abell 53 (Aquila)
The objects listed above are located between 18:00 and 20:00 hours of right ascension.