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Stardust Monthly newsletter of the Astronomical Society of Harrisburg, Pa., Inc. Perseid Watch at Weiser State Forest August 12-13 This year’s Perseid Meteor shower will be favored with a nearly New Moon and darkness. ASH members will travel to our dark sky observing site in Weiser State Forest, near Elizabethville. The site, the Haldeman Tract, is a large open field with good horizons and a low Harrisburg light dome to the South. A Forest Service automated weather station is at the end of the 900 foot long field. Sunset will be at 8:08 pm and observing with telescopes can begin by 8:30 for Saturn and bright stars. The radiant of the meteor shower will rise about 10 pm and the peak meteor count will be in the morning hours. For directions see the Members Only page on the ASH website, astrohbg.org. Construction is in progress on Route 225 over Peter’s Mountain, so from the South you should use PA Route 147 from just before the US 322 bridge across the River. Members will rendezvous at the Rutter’s near the intersection of PA 147 and PA 225, just before Halifax. We will leave promptly at 7:30. In case of questionable weather, a message will be placed on the observatory answering machine after 6 pm. The site is 45 minutes north of Harrisburg. It’s covered with high grass and is deer country so observers should bring along beach or folding chairs, a blanket, snack and warm drinks. For more contact Bob Young at 717-234-4616 or [email protected]. Vol. 60: No. 8 August 2015 The next meeting of the Society will be Monday August 10, 7:30 pm at the Naylor Astronomical Center, 670 Observatory Drive, Lewisberry. A business meeting and discussion of astronomy topics may be followed by observing. Guests are welcome. Camp Kirchenwald visit On July 29th a group of ten middle-schoolaged campers with five college-aged counselors and chaperones visited Naylor Observatory. After a quick first peek at the moon, Charlie Oldland gave a slide presentation on Pluto and New Horizons in the Asper building. After twilight ended, the kids observed through a mixture of binoculars, to small telescopes, to the large telescopes at the observatory. The visit to the observatory is always the highlight of the Night Hawks week at the camp. Thanks to Charlie Oldland for putting this together, and Jim Davis, Roxanne Kamin, Dave Mitsky, Mike Snider, Conrad Weiser and Bob Young for assisting. Anyone interested in making optics? Kevin Fredrick is interested in putting together a group to learn how to make optics. He is willing to assist in getting the group going. Contact me at [email protected] if interested and I will get you in contact with Kevin. Astronomical Society of Harrisburg August 2015 Page 2 Elected Officers, Trustees and Appointed Committees Officers: Trustees: Committee Chairs: President Secretary Term 2014-2015 Membership – Charles Oldland Mike Snider Jim Davis Max Byerly Member Star Parties – Vickie Strohecker 413 Witmer Road 104 Rose of Sharon Dr Keith Potteiger (717) 438-3757 Hershey Pa 17033 Etters Pa 17319 Roxanne Kamin Scheduled Public Observing – [email protected] [email protected] (717)512-6712 (717) 802-0931 Vice President Treasurer Term 2014-16 Group Public Observing – Doug Grove Charles Oldland III Jerry Follett John Koller (717) 652-2674 3973 Chestnut St. 539 Wert Road Bob Grabau Observatory Maintenance – Harrisburg PA 17109 Millersburg, PA 17061 Chip Templin (717) 652-7097 (717) 497-2582 Conrad Weiser (717) 434-6637 [email protected] [email protected] [email protected] Electricity – Jerry Follett [email protected] Kevin Tarr (717) 432-5955 [email protected] Stardust Editor Jim Davis Astronomy Course; Key Training – Bob Young Publicity – Weiman Kissinger (717) 866-7494 [email protected] Websites & IT – Bob Grabau (717) 761-7297 Facebook Pages – Max Byerly ASH August-September Activities Calendar August Sunday, August 2, 9, 16, 23 and 30 – Public Observing Session at Naylor, 8:00 – 11:00 pm. Monday, August 10 - ASH General Meeting at Naylor Observatory, 7:30 pm. Wednesday, August 12 - Perseid Meteor watch at Weiser State Forest. Bob Young is coordinating. Saturday, August 15 – Executive Committee Meeting at Naylor, 10 - 11:30 am. September Treasurer’s Report Summary June 30, 2015 Beginning Balances Checking Astronomy for All PayPal CD’s (3) Total Available June 1 $17,067.45 $125.00 $1,755.22 $3,093.20 $ 22,040.87 Sunday, Sept 20– Public Observing Session at Naylor, 7:30 – 10:30 pm. Monday, Sept. 14 - ASH General Meeting at Naylor Observatory, 7:30 pm. Saturday, Sept 19 – Executive Committee Meeting at Naylor, 10 - 11:30 am. Income Expenses Ending Balance $ 5,201.62 ($1,699.05) $ 25,543.44 Respectfully submitted by Charlie Oldland, Treasurer Astronomical Society of Harrisburg August 2015 Page 3 First Detection of Lithium from an Exploding Star (European Southern Observatory ESO1531) The chemical element lithium has been found for the first time in material ejected by a nova. Observations of Nova Centauri 2013 made using telescopes at ESO’s La Silla Observatory, and near Santiago in Chile, help to explain the mystery of why many young stars seem to have more of this chemical element than expected. This new finding fills in a long-missing piece in the puzzle representing our galaxy’s chemical evolution, and is a big step forward for astronomers trying to understand the amounts of different chemical elements in stars in the Milky Way. The light chemical element lithium is one of the few elements that is predicted to have been created by the Big Bang, 13.8 billion years ago. But understanding the amounts of lithium observed in stars around us today in the Universe has given astronomers headaches. Older stars have less lithium than expected, and some younger ones up to ten times more. A team led by Luca Izzo (Sapienza University of Rome, and ICRANet, Pescara, Italy) has now used the FEROS instrument on the MPG/ESO 2.2-metre telescope at the La Silla Observatory, as well the PUCHEROS spectrograph on the ESO 0.5-metre telescope at the Observatory of the Pontificia Universidad Catolica de Chile in Santa Martina near Santiago, to study the nova Nova Centauri 2013 (V1369 Centauri). This star exploded in the southern skies close to the bright star Beta Centauri in December 2013 and was the brightest nova so far this century — easily visible to the naked eye. The very detailed new data revealed the clear signature of lithium being expelled at two million kilometres per hour from the nova. This is the first detection of the element ejected from a nova system to date. Co-author Massimo Della Valle (INAF–Osservatorio Astronomico di Capodimonte, Naples, and ICRANet, Pescara, Italy) explains the significance of this finding: “It is a very important step forward. If we imagine the history of the chemical evolution of the Milky Way as a big jigsaw, then lithium from novae was one of the most important and puzzling missing pieces. In addition, any model of the Big Bang can be questioned until the lithium conundrum is understood.” The mass of ejected lithium in Nova Centauri 2013 is estimated to be tiny (less than a billionth of the mass of the Sun), but, as there have been many billions of novae in the history of the Milky Way, this is enough to explain the observed and unexpectedly large amounts of lithium in our galaxy. Authors Luca Pasquini (ESO, Garching, Germany) and Massimo Della Valle have been looking for evidence of lithium in novae for more than a quarter of a century. This is the satisfying conclusion to a long search for them. And for the younger lead scientist there is a different kind of thrill: "It is very exciting,” says Luca Izzo, “to find something that was predicted before I was born and then first observed on my birthday in 2013!” Astronomical Society of Harrisburg August 2015 Michael Hutchinson caught Jupiter and Venus a couple of days before closest conjunction Dave Mitsky captured a shot of the Camp Kirchenwald kids visiting Naylor Roxanne Kamin has created a new sign to let visitors know what’s happening in the sky that night Page 4 The Eagle Nebula M16 by Jim Davis taken at Cherry Springs State Park The Trifid M20 and Lagoon M8 Nebulas taken by Jim Davis from Naylor Observatory Bob Young provided a view to the Northeast at our August 12-13 Perseid meteor observing site in Weiser State Forest, near Elizabethville. See article. Astronomical Society of Harrisburg August 2015 Page 5 Minutes of July 13, 2015 ASH General Meeting Mike Snider called the meeting to order at 7:30pm 21 members present. Bob Grabau demonstrated his camera drone which he used to take aerial pictures of the observatory. He took some shots of us during the course of the meeting. Will be useful for taking promotional shots of the observatory and the Cherry Springs Star Party. Kevin Fredrick demonstrated his corrector plate for his off axis telescope design. Kevin gave a presentation on his design for off axis telescopes at the CSSP. His scope was featured in Sky and Telescope. Gadget of the Month: Mike Snider brought his 64mm, 75mm and 86mm eyepieces. Mike Snider showed us his “This is my happy place” sign. Carlie Oldland brought NASA patches, including one for the mission which launched the Hubble Space Telescope. Mike Snider showed his wooden eyepiece plug. One of the venders at the CS Star Party was selling them. They are well made plugs to replace the plastic plug you use in your eyepiece holder. Mike Snider discussed his night myopia glasses, which focus light properly for rod vision. He showed these to people at CSSP. He had 30 people try them out at night, and it improved their vision of dim objects. Book of the Month: Doug Grove shared “The Hubble Cosmos”: 25 chapters of great “moments” history of the Hubble Space Telescope. By National Geographic. Dave Mitsky found a good book in the Mechanicsburg library: “The Accidental Universe : The World You Thought You Knew” by Alan Lightman, a theoretical physicist. Charles Oldland discussed “Hubble's Universe: Greatest Discoveries and Latest Images” by Terence Dickerson. Keith Potteiger has started a club meteor collection. We have bought three nice sized meteors from a vender at the Cherry Springs Star Party. He has them in a case, and has bought small stands to display. He also made cards to describe them. They are being stored in the Asper building. Cherry Springs Star Party update: Review the minutes of the executive meeting which followed. Jerry Follet made a motion to accept the minutes. Chip Templin seconded the motion. Minutes were approved. Financial report. Charles Oldland stressed that two people counted all currency collected at the star party. Two speakers at the star party returned their honorarium checks. We had a few refunds approved for extenuating circumstances which caused people to miss the star party. All the big bills for the Cherry Springs Star Party were paid. Reviewed the June meeting minutes. Left Eric Roth off the list of attendees of the Executive Meeting. Dave Mitsky pointed out that Hickson groups were spelled incorrectly. Mike Snider mailed a few t-shirts to people who did not pick them up at the star party. We are re-opening ordering for CSSP t-shirts for people who still want one. The price includes $8 to ship. Bob Masterson will fill another order for the shirts. Mike Snider called the ASH CSSP team a well-oiled machine. We threw a very good star party. It was great to have two vender tents. We had one conflict between the venders we were able to resolve. The venders donated 103 items for our raffle. Doug Grove presented the painting we picked up from one of the venders at the star party for display in the Asper building. It cost $65. Doug Grove made motion to purchase the picture. Bob Grabau seconded the motion. Motion approved. Public Observing update: On 5 July Jerry Follet, Keith Potteiger and Jim Davis manned the observatory, but it clouded over and we did not open. On 12 July we opened, but the sky was mostly obscured. 17 people showed up. Jerry Follet was able to get the King building roof motor repaired. An electrical part had burned out, along with the strip of LED floor lights. Observation Reports: Doug grove – Observed 10-12 new galaxies in Leo and Virgo. Also observed M13, M51 and M57. Mike Snider – Observed cloud patterns on Venus using a narrow band blue filter at 400x. Mike also observed the Venus-Jupiter conjunction from Florida. He was able to see Ganymede with his naked eye. Dave Mitsky - Observed on June 29, with a sky quality meter reading of 29.5. Observed faint planetary and the galaxies NGC 4605 and NGC 5474, a companion of M101. At the Cherry Springs Star Party: On Thursday night viewed M13 and Saturn through the new Televue Delite eyepieces. On Friday it cleared up a bit after the Astronomical Society of Harrisburg August 2015 Page 6 storms moved through. On Saturday – observed a Comet. On July 23rd observed the Lunar X and Lunar V with his 6 inch Dob. Observed Jupiter and Venus on 5 nights leading up to the conjunction, but on 30 June it was cloudy. On July 3rd he observed a pass by Tiangong 1 space station. Mike Snider – Observed the optical autokinesis while at the star party. He has glow in the dark tripod feet for his Losmandy mount. Roxanne Kamin showed pictures from the star party. One was of Kevin Fredrick’s telescope. He talked a bit about his off axis scope. Kevin Fredrick is interested in getting a group together to make optics. Bob Grabau – Showed the video from his drone of the meeting. Bob Grabau showed an aurora and the belt of Venus taken from the drone. He also showed images of the observatory. He also showed video of he took of the train yard in Shiremanstown. Dave Mitsky showed some of the latest Pluto pictures from the New Horizons mission. He also showed a shot of Sunset on June 23rd. He showed afocal shots of the Lunar X and the Lunar V. He also had a shot of Jupiter and Venus taken through a short tube 80mm scope, along with the Full Moon from July 1st. Charles Oldland will be hosting about a dozen kids from Camp Kirchenwald at Naylor Observatory. They will be here the 23rd, with a rain date of the 25th. Request 1 hour presentation at Camp Catherin has requested that an ASH member give a one hour presentation on astronomy, Monday, Tuesday or Thursday the week of the 20th. Charles Oldland will make the presentation unless someone else volunteers. Jim Davis reported that he fixed the 114mm Celestron Newtonian scope. The hand controller had been lost. He found a used handset and mount head on Ebay as a replacement. This scope is available for members to borrow. Bob Grabau made a motion to adjourn the meeting. Dave Mitsky seconded the motion. Meeting adjourned at 9:33pm. Minutes of July 18, 2015 Executive Committee Meeting Meeting called to order at 10:15, Mike Snider, Doug Grove, Jim Davis, Chip Templin, Keith Potteiger, Bob Grabau and Charlie Oldland attending. Discussed allocating money for next year’s Star Party. We also need to decide what we need to spend on each of the building for the next year. We need to replace the computer in the Weiser building. Need to look at weatherizing the computer setup in the building. Jim Davis will look into computer replacements. Asper building – Need to buy a new projector. The current projector is too low resolution, and is causing problems using it with modern computers. Bob Grabau will look into options for a new projector. Discussion on buying camera for the Weiser building. Discussed whether to buy a CCD camera with a filter wheel. Also discussed buying a planetary camera, or a lower end camera for beginners to use. Discussed a number of options for purchasing. Bob Grabau will look into CCD cameras. Discussed next year’s budget based on the results of the star party. Still need to determine the donation amount we will be giving to the Dark Sky Fund. Doug Grove made a motion that we make a $2000 donation. Bob Grabau seconded the motion. Motion approved, will present to the general meeting for approval. Discussed replacing the focuser on the 17” Cassegrain. Need to get specifications on the current focuser to determine the movement range. We discussed purchasing eyepieces for each telescope. Mike Snider and Keith Potteiger will make recommendations. Need to have more staff t-shirts per individual at next year’s star party. Doug made a motion to purchase more next year. Bob Grabau seconded the motion. Motion was approved. We are taking orders for a second batch of T-shirts for the star party. We will post the order form on the web site, and send out a notice to attendees. Have it open for 4 weeks for orders. We need to purchase an Argo Navis for 12 inch in the Culver Building. Jim Davis will get a quote. We decided that the 2019 dates for the Cherry Springs Star Party will be 30, 31 May and 1, 2 June. We discussed the damage to the observatory driveway. Discussed what we need to do. We will have Conrad Weiser come up with a few options for how to repair the driveway. Reviewed this month bills. Doug made motion to pay the bills. Chip Templin seconded the motion. Motion approved. Motion Doug made a motion to adjourn, Charlie seconded the motion, meeting adjourned at 11:46. Astronomical Society of Harrisburg Dave Mitsky’s August 2015 Page 7 August Celestial Calendar All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT) 8/1 The astronomical cross-quarter day known as Lammas or Lughnasadh occurs today 8/2 The Moon is at perigee, subtending nearly 33'13'' from a distance of 362,139 kilometers (252,023 miles), at 10:00; Saturn is stationary at 20:00 8/5 Mercury is 8 degrees north of Venus at 9:00; Uranus is 1 degree north of the Moon, with an occultation occurring in the Falkland Islands, southern South America, and Antarctica, at 9:00 8/7 Last Quarter Moon occurs at 2:03; Mercury is 0.6 degree north of Jupiter at 4:00; Mercury is 1.0 degree north of the first-magnitude star Regulus at 15:00 8/8 Venus is at aphelion today; asteroid 2 Pallas is stationary at 12:00; the Curtiss Cross, an X-shaped clair-obscur illumination effect located between the craters Parry and Gambart, is predicted to occur at 16:26 8/9 The Moon is 0.7 degree north of the first-magnitude star Aldebaran (Alpha Tauri), with an occultation occurring in northwestern Canada, Alaska, northwestern Asia, Russia, Scandinavia, the Middle East, and eastern Europe, at 0:00 8/10 Jupiter is 0.4 degree north of the first-magnitude star Regulus at 23:00 8/13 Mars is 6 degrees north of the Moon at 5:00; the peak of the Perseid meteor shower (a zenithal hourly rate of 60 to 100 per hour) occurs at 6:00 8/14 New Moon (lunation 1146) occurs at 14:53 8/15 Venus is in inferior conjunction at 19:00; Mercury is 2 degrees north of the Moon at 15:00 8/16 Asteroid 4 Vesta is stationary at 6:00 8/18 The Moon is at apogee, subtending 29'17'' from a distance of 405,848 kilometers (252,182 miles), at 3:00 8/19 Mercury is at the descending node today 8/20 Mars is 0.5 degree south of the bright open cluster M44 (the Beehive or Praesepe) in Cancer at 16:00 8/22 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 occur at 1:25; Saturn is 3 degrees south of the Moon at 17:00; First Quarter Moon occurs at 19:31 8/26 Jupiter is in conjunction with the Sun at 22:00 8/29 Mercury is at aphelion today; Full Moon (known as the Fruit, Grain, Green Corn, or Sturgeon Moon) occurs at 18:35 8/30 The Moon is at perigee, subtending nearly 32'59'' from a distance of 358,290 kilometers (222,631 miles), at 15:00 8/31 Venus is at its greatest heliocentric latitude south today John Flamsteed and Maria Mitchell were born this month. The gibbous phase of Mars was first observed by Francesco Fontana on August 24, 1738. William Herschel discovered Enceladus on August 28, 1789. Asaph Hall discovered Deimos on August 11, 1877 and Phobos on August 17, 1877. The peak of the Perseid meteor shower is not adversely affected by moonlight this year. Comet 109P/Swift-Tuttle is the source of Perseid meteors. For more on this year’s Perseids, see pages 48-50 of the August issue of Sky & Telescope or click on http://www.timeanddate.com/astronomy/meteor-shower/perseid.html and http://earthsky.org/astronomy-essentials/everything-you-need-to-know-perseid-meteor-shower The Moon is 15.9 days old, is illuminated 99.6%, and is located in Aquarius on August 1st at 0:00 UT. The Moon is at its greatest northern declination on August 10th (+18.3 degrees) and its greatest southern declination on August 25th (-18.2 degrees). Longitudinal libration is at a maximum of +6.2 degrees on August 9th and -7.3 degrees on August 24th. Latitudinal libration is at a maximum of +6.7 degrees on August 10th and a minimum of -6.8 degrees on August 25th. The Moon passes two degrees south of Mars on August 13th, two degrees south of Mercury on August 15th, and three degrees north of Saturn on August 25th. New Moon (i.e., the dark of the Moon) occurs on August 14th. The Moon is at perigee on August 2nd and August 30th and apogee on August 18th. Large tides will take place on August 31st. The Moon occults Uranus on August 5th and Aldebaran on August 9th from certain parts Astronomical Society of Harrisburg August 2015 Page 8 of the world. Browse http://www.curtrenz.com/occultations and http://www.lunaroccultations.com/iota/bstar/bstar.htm for information on lunar occultations. Visit http://saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars/ for tips on spotting extreme crescent Moons. Times and dates for the lunar light rays predicted to occur in August are available at http://www.lunaroccultations.com/rlo/rays/rays.htm The Sun is located in Cancer on August 1st. Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on August 1: Mercury (magnitude -1.2, 5.1", 95% illuminated, 1.33 a.u., Cancer), Venus (magnitude -4.4, 52.1", 7% illuminated, 0.32 a.u., Gemini), Mars (magnitude +1.7, 3.6", 99% illuminated, 2.58 a.u., Cancer), Jupiter (magnitude -1.7, 31.1", 100% illuminated, 6.33 a.u., Cancer), Saturn (magnitude +0.4, 17.3", 100% illuminated, 9.60 a.u., Libra), Uranus (magnitude +5.8, 3.6", 100% illuminated, 19.42 a.u. on August 16th, Pisces), Neptune (magnitude +7.8, 2.4", 100% illuminated, 28.99 a.u. on August 16th, Aquarius), and Pluto (magnitude +14.1, 0.1", 100% illuminated, 32.14 a.u. on August 16th, Sagittarius). This month Mercury, Venus, and Jupiter are visible in the west, Saturn in the southwest, and Neptune in the east during the evening. At midnight, Saturn can be found in the southwest, Uranus in the east, and Neptune in the southeast. In the morning, Venus and Mars are in the east, Uranus is in the south, and Neptune is in the southwest. At midmonth, Mercury is visible in evening twilight, Mars rises at 5:00 a.m. local daylight time, Jupiter is visible in evening twilight, and Saturn sets at midnight for observers at latitude 40 degrees north. Mercury and Jupiter form a close pair from August 5th through August 8th. The two planets lie within a degree of each other on August 6th and August 7th. On the evening of August 6th, Jupiter (magnitude -1.7) is 0.6 degree to the lower left of Mercury (magnitude -0.7). Mercury is in the process of entering the evening sky this month and Jupiter is in the process of exiting it. Mercury is two degrees north of the waxing crescent Moon on August 15th and is at aphelion on August 29th. As August progresses, Mercury increases its angular separation from the Sun, attaining an altitude of seven degrees above the western horizon 30 minutes after sunset by August 31st. On the evening of August 1st, Venus is less than 7% illuminated and appears as a very thin crescent 53 arc seconds in size. When Venus reaches aphelion on August 8th, it will be approximately 2.5 light-minutes from the Earth. Venus passes almost eight degrees south of the Sun when it is in inferior conjunction on August 15th. Venus and Mars are nine degrees apart on August 29th, the second of three conjunctions of the two planets this year. Venus rises more than 90 minutes before the Sun by month’s end. By that time, it increases in brightness to magnitude -4.5, decreases in apparent size to 52 arc seconds, and increases in phase to 9% illuminated. Mars emerges from the glare of the Sun during morning twilight as August progresses. At midmonth, it shines faintly at magnitude +1.7 as it rises 90 minutes before sunrise. By the end of August, Mars rises two hours before the Sun. The Red Planet passes by the open cluster M44 on the mornings of August 20th and August 21st but observing the two objects will be rather difficult. Jupiter disappears into evening twilight during early August. The gas giant is in conjunction with Mercury on August 7th. On August 10th, Jupiter undergoes the only conjunction with Regulus in this cycle of its 12-year-long orbit. Jupiter is in conjunction with the Sun on August 26th. During August, Saturn is positioned 13 degrees northwest of the first-magnitude star Antares. The Ringed Planet subtends 17 arc seconds in angular size this month. Its rings are inclined by 24 degrees and span 38 arc seconds. On August 2nd, Saturn ends its retrograde motion through eastern Libra. Saturn is at eastern quadrature (i.e., 90 degrees east of the Sun) on August 21st. It is 9% smaller at that time than at opposition and appears more three dimensional than usual due to the greater angle of the sunlight illuminating the planet. Eighth-magnitude Titan, Saturn’s largest satellite, is due north of the planet on August 7th and August 23rd and due south on August 14th and August 30th. The peculiar satellite Iapetus shines at tenth magnitude as it passes 8.3 arc minutes from Saturn and reaches greatest western elongation on August 6th. It fades to eleventh magnitude by August 25th when it is 2.1 arc minutes north of Saturn. For additional information on Saturn’s satellites, browse http://www.skyandtelescope.com/observing/interactive-sky-watching-tools/ Uranus rises approximately 90 minutes after Neptune and can be found 0.6 degree from the fifth-magnitude star Zeta Piscium this month. During the course of August, Uranus moves from a position southeast of that star to one that's slightly southwest. Astronomical Society of Harrisburg August 2015 Page 9 Neptune continues to retrograde through Aquarius. The eighth planet is located 3.4 degrees southwest of Lambda Aquarii at the end of August. It reaches opposition (magnitude +7.8, apparent diameter 2.4 arc seconds) for Western Hemisphere observers on August 31st. Finder charts for Uranus and Neptune can be found at http://www.nakedeyeplanets.com/uranus.htm and http://www.nakedeyeplanets.com/neptune.htm and at http://www.skyandtelescope.com/wpcontent/uploads/WEB_UrNep_Finders.pdf On August 1st, Pluto is positioned approximately midway between the stars Xi-1Sagittarii (magnitude +5.0) and Xi2 Sagittarii (magnitude +3.5). It is about 35 arc minutes west-northwest of Xi2 Sagittarii by the end of August. 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 http://www.bluewaterastronomy.info/resources/MapsCharts/planets2015/22pluto_2015_1.pdf For more on the planets and how to locate them, see http://www.nakedeyeplanets.com/ The fragmented periodic comet 141P/Machholz reaches perihelion on August 24th. Assuming the pieces have not completely disintegrated, the comet may be visible as it passes between the bright open clusters M36 and M38 in Auriga on the mornings of August 7th and August 8th. Comet C/2013 US10 (Catalina), which is currently visible from the southern hemisphere, travels northward, passing near the first-magnitude star Alpha Centauri as August ends. For further information on comets visible this month, browse http://cometchasing.skyhound.com/ and http://www.aerith.net/comet/future-n.html Asteroid/dwarf planet 1 Ceres shines at eighth magnitude as it travels southwestward through eastern Sagittarius this month. It passes 0.3 degree north of the fifth-magnitude star SAO 211782 on August 20th and August 21st. Asteroid 100 Hekate (magnitude +10.8) reaches opposition on August 2nd, asteroid 65 Cybele (magnitude +11.1) on August 13th, and asteroid 21 Lutetia (magnitude +9.4) on August 15th. For information on asteroid occultations taking place this month, see http://www.asteroidoccultation.com/2015_08_si.htm Free star maps for August can be downloaded at http://www.skymaps.com/downloads.html and http://www.telescope.com/content.jsp?pageName=Monthly-Star-Chart 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.