Hamilton Amateur Astronomers February 1999 Volume 6 Issue 4 Mere Mir Mirror Math has an angular diameter of 1800 arcsec (or half a degree of arc), the What about the size of the solar fraction of the Sun's rays seen on image on the Earth's surface T hankfully, technical difficulties scuttled the deployment of a giant the ground would be at most (15 / produced by this beautiful "space mirror" from the Mir space 18000)2 or, said differently, one reflecting pinhole? It is just the station on Feb 3rd. This rather zany part in 14,400. The Sun has a diameter of the solar disk in idea involved a 25m diameter magnitude of -26.5 (that is, radians (about 1/115) times the metallized-mylar structure which BRIGHT!). The mirror would altitude of 350 km which equals would be oriented to direct therefore have a brightness of - about 3 km. If we are feeling sunlight - when it was actually in 26.5 + 2.5 log10 (14,400) = -16.1. generous, we will say that it isn't a sunlight itself! This is roughly 4 magnitudes very high quality mirror and brighter than the full moon - all in therefore the image will be It is easy to confirm rough estimates that 15 arcsec region on the sky. somewhat spread out - and of its brightness with a few This gives new meaning to the consequently dimmer at seen from background facts. The Mir space lyric about wearing your a given place on the ground. station orbits at an altitude of 350 sunglasses at night! According to km or 350,000 m. With a diameter this calculation, it could be up to The whole thing doesn't sound of 25m and when overhead, the 40 times brighter than the full very practical - and isn't. largest axis would subtend an angle moon. of 206265 * 25 / 350,000 = 15 Low-earth orbit is not a good arcsec. This is the size of the region Of course, there are a number of place to reflect sunlight from since of the Sun's surface which could be things that take the brightness most of the time both the ground reflected in the mirror as seen from down a few notches: reflectivity of and the satellite are either in the Earth's surface. Since the Sun the coating (liable to be about 70- darkness or in light at the same 80%), being downrange - Mir can time. Supposedly the whole be seen quite a distance off the enterprise is justified by being zenith, and the projected area of able to combat the long Russian the oriented mirror - which MUST winters with some extra sunlight. be tilted to redirect sunlight, However, winter is the time when presumably at about 45 degrees. the period when the ground is in All of these factors will conspire darkness and Mir is in sunlight to lower the total brightness into for the shortest period of time!! the published range of about 10 times the brightness of the full Doug Welch moon. welch@physics.mcmaster.ca Chair's Report page 2 Rob'serving Report page 8 inside... Constellation of the Month page 3 Calendar of Events page 8 The Legend of I-Hsing page 5 March Star Chart page 9 Page 2 Chair's Report of images listed by NGC number at II t is unfortunate that we had to cancel last month's general h t t p : / / w w w . a s p s k y . o r g / h t m l / meeting. Considering the severity of resources/ngc.html. I have tried to the weather we had little choice find images of particular objects on though. The good news is that our the web and had to search through speaker, Dr. Melinda Weil, has kindly many useless links before finding EE vent Horizon is a publication of the Hamilton Amateur agreed to reschedule her talk to the what I wanted. It's nice to go to just Astronomers (HAA). March general meeting. While on the one site for so many of those topic of upcoming meetings, we will images. For those of you who have The HAA is an amateur astronomy be holding a members' night in either the software program ECU it's a club dedicated to the promotion and April or May. This is your chance to great source of pictures for your enjoyment of astronomy for people of show off your slides, tell us about "images" directory. The next site all ages and experience levels your telescope or perhaps a project located at http://www.blackskies. that you are working on. Ann Tekatch com/index1.html is a must for The cost of the subscription is will be making one of the anyone who is interested in included in the $15 individual or $20 presentations, which will be all about planetary nebulae. There are images family membership fee for the year. reading star charts. You won't want to and sketches, a database of 1,143 Event Horizon is published a miss this especially if you are a objects, 400+ observing reports, minimum of 10 times a year. beginner since knowing how to use information on nebula filters, star charts is crucial to successful observing tips, and a page of HAA Council observing. astronomy links that contains both Chair S tewart Attlesey links to other planetary nebula sites, Second Chair Doug Welch I have two more astronomy related and general astronomy sites. This is Secretary Marg Walton web sites for a site that you really shouldn't miss. Treasurer Barbara Wight you to check Obs. Dir Rob Roy out this month. Stewart Attlesey Editor Rosa Assalone The first is a attlesey@interlog.com Membership Dir. Ev Rilett source of a HAJA Coord Rosa Assalone huge number Councillors Ann Tekatch Ray Badgerow Editor's Report Steve Barnes John McCloy Gary Sutton TT hank you for all the articles Also, you may want to make special Web Site that were sent in this note of the cosmology meeting on http://amateurastronomy.org/ month. There are many great articles February 27th. It's going to be and I am sure everyone will throughly quite interesting. The ad on page 10 enjoy reading this issue of Event explains the meeting further. Horizon. If you want to get into observing variable stars be sure to The deadline for submitting articles read the information on pages 6 and 7. and pictures for the next newsletter is Friday, March 5th. Remember to read the calendar of events on page 8 to find out when Rosa Assalone everything is happening in February 540-8793 and March. Please note that the assalor@mcmaster.ca February meeting of HAJA is not the third Tuesday of the month this time. Event Horizon - Hamilton Amateur Astronomers Page 3 Constellation of the Month - Ursa Major - Margaret Walton the story this way. Zeus and his the most notable being Polaris, the II lover Callisto had a son, whom North Star in the constellation Callisto named Arcas. Zeus' Ursa Minor. The early Britons saw n December 1995 the wife Hera was jealous and The Big Dipper as King Arthur's Hubble Space Telescope turned Callisto into a bear. Years Chariot. Many other cultures such pointed its camera at a later, when Arcas was grown, as the Irish, Danish, Teutons, seemingly empty spot in Ursa Callisto saw him hunting in the Vikings and Polish also identified it Major. The field was devoid of forest. Forgetting she was a as a chariot or wagon. bright nearby galaxies, stars, bear, she rushed to greet him. known nearby clusters and bright Seeing only a bear about to kill While Ursa Major never sets at our radio sources. The camera him, he drew his bow to shoot latitude, its midnight culmination is imaged the area for 10 her. Zeus was watching, in March. consecutive days. The result is grabbed Callisto by the tail and the famous Hubble Deep Field, flung her into the heavens, an image filled with galaxies of where she became Ursa Major. Objects to See incredible shapes and sizes. Wanting mother and son While our observing scopes can't together, he changed his son M40: This asterism is a double see those galaxies, there are into a bear as well, grabbed his star of magnitude 8. many objects we CAN see in this tail and threw him into the constellation. heavens, forming Ursa Minor. M81 (NGC3031): Bode's Nebula. Very large, bright, elongated Ursa Major has been identified Ursa Major contains one of the galaxy with a bright nucleus. It as a bear by almost every group, most recognized star patterns, or has a magnitude of 8.4 and as per not only the Greeks and the asterisms, in the sky - the the NGC is a (!) remarkable Romans, but the Iroquois and Plough, or The Big Dipper. The object. It is separated from M81 Algonquin tribes of North Big Dipper is used as a pointer by .5 degrees. America as well. The Greeks tell to other stars and constellations, (Continued on page 4) Event Horizon - Hamilton Amateur Astronomers Page 4 Constellation of the Month - Ursa Major (Continued from page 3) arms. Magnitude is 10.4. Astro Quiz: M82 (NGC3034): Cigar Galaxy. NGC3631: Bright, large round Size Does Matter This is the smallest of the galaxy with two straight large Messier Galaxies and is a very arms. Magnitude is 10.4. Denise Kaisler bright, large elongated galaxy. kaisler@astro.ucla.edu N G C 3 6 7 5 : B r i g h t , l a r g e M97 (NGC3587): Owl Nebula. elongated galaxy with two main What's the difference between a As per the NGC, this is a (!!) arms. Magnitude is 10.2. planet and a moon? Well if you're remarkable object. Gaps in the talking about terrestrial planets, the nebula form the owl's 'eyes'. It is NGC3726: This Seyfert galaxy is answer is : not a whole lot. Below is a very bright, large round nebula bright, large and elongated with a list of planets and satellites. See if with a magnitude of 9.9. several arms. Magnitude is you can put them in order of size, 10.4. from largest to smallest. M101 (NGC5457): This is a bright, large face-on galaxy with NGC3893: Bright, large round faint spiral arms. Its magnitude galaxy with two main arms. It ___ Mars is 7.7. This is possible the same forms a pair with NGC3896. ___ Uranus object as M102. Magnitude is 10.5. ___ The Moon ___ Ganymede M109 (NGC3992): Bright, large NGC3938: This is a face-on ___ Mercury elongated galaxy with spiral spiral galaxy. It is bright, large ___ Neptune arms. Magnitude is 9.8. and round with several bright ___ Titan arms. Magnitude is 10.4. ___ Venus IC2574: Coddington's Nebula. ___ Europa This is a very large, very faint NGC3941: Bright, large round ___ Earth galaxy with a magnitude of 10.6. galaxy with a magnitude of 10.3. ___ Pluto It is in the M81 Galaxy Group and has a stellar group at one NGC3953: This spiral galaxy is end. bright, large and elongated. It has many arms and a small Answer below: NGC2681: This is a very bright, nucleus. Its magnitude is 10.1. very large galaxy with a bright nucleus. Magnitude is 10.3. NGC4051: This Seyfert galaxy is bright and very large with two NGC2768: A bright, large spiral arms. Magnitude is 10.3. elongated galaxy with a bright nucleus. Magnitude is 10.0. N G C 4 6 0 5 : B r i g h t , l a r g e elongated galaxy with a NGC2841: A bright, large magnitude of 10.3. elongated galaxy with spiral arms and a bright nucleus. NGC5322: Bright large galaxy Magnitude is 9.3. with a magnitude of 10.0. NGC3077: This galaxy is located near the M81 galaxy group and is a bright, large round galaxy Pluto with a magnitude of 9.9. Europa The Moon NGC3184: Bright, large round Ganymede galaxy with two main arms. Mercury Magnitude is 9.8. Titan Mars Venus NGC3198: A bright, large, Earth elongated galaxy with several Neptune Uranus Event Horizon - Hamilton Amateur Astronomers Page 5 The Legend of I-Hsing adapted by Denise Kaisler mean?" "I have a task for you which is of greatest importance. Hear me I-Hsing replied, "This sort of thing well, and do not fail me, or you has happened before. In the Later shall receive the harshest Wei dynasty they even lost the II -Hsing was a great astronomer of the Tang punishment. Now take this bag planet Mars. But there are no dynasty (600-900 A.D.) who came and go to the ruined garden, previous records of the from very poor circumstances. In beyond the palace walls. There, disappearance of the Great Bear. his youth, his neighbor Wang- you must hide yourselves from Heaven must be giving your Liao, did him many great favours. noon to until midnight. Listen Majesty warning of an impending Wang-Laio was so generous that closely now. If something should disaster." I-Hsing swore to help him, appear that numbers seven, you however he might. must take it with you and store it "I knew it! The Emperor in this pot. Mind you get all exclaimed. "But tell me, what can Many years later, Wang-Liao was seven! If even one is lost, we are be done?" imprisoned for having killed a undone." man. I-Hsing traveled a great way "Your Majesty, a display of virtue to visit his former benefactor. Though it was an exceedingly by the Son of Heaven can surely strange request, the servants did as influence the stars. It is my "I-Hsing," pleaded the condemned they were told. opinion that a decision in favor of man, "your have risen high in the life, rather than death, would Emperor's court because of your It came as a great surprise to them affect them most." great learning. The Emperor when, at six o' clock in the himself finds favor with you. Can evening, a herd of seven pigs And so it came to pass that the you not aid me?" wandered past their hiding place. Emperor issued a general amnesty Immediately the two sprang out and all prisoners were freed. Later, But I-Hsing was not moved. "I can and ran after the pigs. Now, as the seven stars of the Great Bear get you gold and silver aplenty, anyone knows it is a great labour reappeared in the heavens. And but I cannot change the law," he to catch and hold seven, squealing, when the pot which had contained said. struggling pigs, but the servants the pigs was opened, it was found did not wish to be punished. When to be empty. At that, Wang-Liao's anger burst the animals had been dragged forth "What good was it to me that home and stored in the pot, the from Joseph Needham's Science and I ever knew you!" Civilization in China, v3. pg 282 servants ran to fetch I-Hsing, who covered the pot with a lid and I-Hsing left the prison, but with a wrote Sanskrit symbols upon it in heavy heart. For many days red. afterwards he thought about this grave situation. He was deeply That very evening, I-Hsing was indebted to Wang-Liao and was summoned by the Emperor well aware of his own oath. But to himself. The Son of Heaven was ask the Emperor to pardon a pacing back and forth, clearly in a condemned murder? How was it state of great agitation. possible? I've just received a message from At last, I-Hsing came up with a the head of the Astronomical plan. He summoned two of his Bureau," he said. "They have most loyal servants to a room of informed me that the Great Bear is his house, where there was missing from its usual place in the nothing but a large iron pot. sky! Oh, I-Hsing, what can it Event Horizon - Hamilton Amateur Astronomers Page 6 SS AAVSO ALERT NOTICE 253 (January 28, 1999) PECIAL and UNIQUE Additional observations of the All AAVSO observers - visual OPTICAL MONITORING immediate region around this event, o b s e r v e r s , p h o t o e l e c t r i c REQUEST: 1522+45 GRB obtained by numerous astronomers p h o t o m e t r i s t s , a n d C C D 990123-GAMMA-RAY BURSTER at several institutions (see IAU photometrists - are strongly urged to E V E N T W I T H B R I G H T Circulars 7094, 7095, 7096, 7098, monitor this location as much as OPTICAL COUNTERPART 7099, 7100), indicate that the possible over the coming months, and optical counterpart of the gamma- to report any sudden brightening to We have been informed by the ray burst continued to fade very AAVSO Headquarters immediately. Central Bureau for Astronomical quickly, reaching R magnitude If you see any brightening at the Telegrams (IAU Circulars 7094, approximately 18 in less than 4 position of GRB 990123, please 7095, 7100), Dr. Howard Bond, hours and fainter than R magnitude monitor it constantly and report the Space Telescope Science Institute, 19 in less than another 5 hours, and timing of your observations very and Dr. Chryssa Kouveliotou, NASA fainter than R magnitude 21 in accurately, to the fourth decimal of Marshall Space Flight Center and another 24 hours. the J.D. We recommend that you BATSE Team member, that a have a tape recorder at hand when gamma -ray burst accompanied by an The position of the optical you are observing and record your unprecedentedly bright optical flash counterpart was reported by S. C. observations into the tape recorder, has been detected by the Burst and Odewahn, J. S. Bloom, and S. R. for the sake of speed. Transient Source Experiment Kulkarni, California Institute of (BATSE) instrument aboard the Technology, on behalf of the Accompanying is an AAVSO Compton Gamma Ray Observatory C a l t e c h -N R A O-CARA GRB preliminary "d" scale chart prepared satellite on January 23.40764 UT, and Collaboration (IAU Circular 7094) by C. Scovil using Tycho photometry, by the Gamma Ray Burst Monitor as: and approximate V magnitudes instrument aboard the BeppoSAX derived from USNO A2.0 magnitudes satellite on January 23.40780 UT. R.A. = 15h 25m 30.5s via the vsnet chart for this object. The BeppoSAX Wide Field Camera 1 Decl. = +44 degrees 46' 00" (2000) also detected the burst and observed Anyone interested in being alerted the x-ray counterpart. This event is potentially a very by the Gamma Ray Burst important one for our observers Coordinates Network should write Interested astronomers were because the bright optical flash may to Dr. Scott Barthelmy at immediately alerted via BATSE's occur again once or several times, scott@milkyway.gsfc.nasa.gov. Gamma Ray Burst Coordinates and so the area should be Network. C. W. Akerlof and T. A. monitored. As Dr. Bond explains, The followin g websites with McKay, University of Michigan, "...An exciting aspect of this object information on this object may also be report on behalf of the Robotic is the suggestion by S.G. of interest to our observers: Optical Transient Search Experiment Djorgovski et al. that GRB 990123 (ROTSE) collaboration (Michigan/ was gravitationally lensed (which http://science.msfc.nasa.gov Los Alamos National Laboratory/ might account for the extraordinary http://astro.caltech.edu/~jsb/GRB/ Lawrence Livermore National apparent luminosity). This raises grb990123.html Laboratory) that within 30 seconds, the possibility, emphasized by E. http://gcn.gsfc.nasa.gov/gcn/gcn3/199. the ROTSE-I telephoto camera array Turner, that the gamma -ray and gcn3 at Los Alamos, NM, which uses an optical bursts may recur in the next unfiltered broadband CCD, was few days to months, due to lensing CHARTS AVAILABLE ON observing the location of the gamma- time delays along different paths to AAVSO WEB AND FTP SITES ray burst, and it observed a very the Earth. It would thus be very bright, rapidly -fading object. Six worthwhile for AAVSO members to Electronic copies of the AAVSO observations made between January monitor this position constantly, chart of GRB 990123 mentioned in 23.407851 and January 23.414677 even with small telescopes or this Alert Notice are available through (approximately 10 minutes) showed binoculars, to search for such our web site at the following address: the object brighten from V magnitude repeated optical transients, which 11.82 to 8.95 and then fade to 14.53. could in principle even reach to http://www.aavso.org Images of these six observations may brighter than 8th magnitude for a be seen at http://www.umich.edu/ few seconds. Precise times, All of these charts may also be ~rotse/gifs/grb990123/990123.gif. magnitude estimates, and other obtained directly from our FTP site: details should be determined for any ftp.aavso.org (198.116.78.5), in / flashes that are seen." alerts/alert253/ Event Horizon - Hamilton Amateur Astronomers Page 7 observations by fax to 617-354- Good observing! The answering machine at AAVSO 0665 or by e-mail through the Janet A. Mattei Headquarters is on nights and Internet to observations@aavso.org. Director weekends for your convenience. Please call our charge-free number Many thanks for your valuable (888-802-STAR = 888-802-7827) to astronomical contributions and your report your observations. We also efforts. encourage observers to send Event Horizon - Hamilton Amateur Astronomers Page 8 Rob'serving Report TT look at its southern hemisphere. March here isn't much going on 03- Mercury at greatest eastern Neptune & Uranus are rising in that's exciting this elongation- 18 deg. Best February in the dawn's twilight. month. A few close planetary evening viewing for 1999. conjunctions will have to do. Don't 05- Zodiacal Light possibly give up, though. Winter is slowly visible in the west after twilight Rob Roy, disappearing and the weather will for the next 2 weeks. Observing Director improve and gradually warm up. rroy@idirect.com The Planets This month's Binbrook observing nights are scheduled for Feb. Mercury is visible in the western 13,19,20 Call Rob Roy (692- sky last week of Feb to first week 3245), Bret Culver (575-9492), or of March. John McCloy (523-4359) at 7pm for local weather conditions and to V e n u s i s a n e v e n i n g c o n f i r m . T h e B i n b r o o k phenomenon setting at about Conservation Area currently has 8:30 pm. Did you know that... some snow and it is not plowed. Mars rises at about 10:30pm in Monthly In-Sights Libra. Increasing in apparent the maximum number diameter to about 12". of eclipses in one year February is seven. There may 18- Venus is 1.8 deg N of thin Jupiter low in the west at dusk, be 5 crescent Moon. setting at about 8 pm. Jupiter is 2 deg N of Moon. solar and 2 lunar or 4 22- Four bright planets are visible Saturn is visible until about 10:30 solar and 3 lunar. in the western sky for the next two pm in Pisces. Its fairly large disk weeks. and the appreciable tilt of the Rob Roy 23- a VERY close conjunction of rings continue to make it a nice Venus only 0.2 deg N of Jupiter. fall object! The tilt of its ring Aldebaran 0.4 deg S of system is steadily increasing Moon. from about 15 degrees as we CALENDAR OF EVENTS * February 12, 13, 19, 20, 8:00pm BINBROOK OBSERVING NIGHTS - For confirmation or directions call Rob Roy at 692-3245 or Bret Culver 575-9492 or John McCloy 523-4359. * Tuesday, February 23, 7:00pm HAJA MEETING - McMaster Burke Science Building, room B148. For more information contact Rosa Assalone at 540-8793. * Friday, February 19, 7:30pm HAA COUNCIL MEETING * Saturday, February 27, 8pm COSMOLOGY DISCUSSION GROUP - In Search of the Edge (see page 10) McMaster Burke Science Building room B148. * Friday, March 12, 7:30pm HAA GENERAL MEETING - At the Spectator Building auditorium * March 12, 13, 19, 20, 8:00pm BINBROOK OBSERVING NIGHTS - For confirmation or directions call Rob Roy at 692-3245 or Bret Culver 575-9492 or John McCloy 523- 4359. * Tuesday, March 16, 7:00p m HAJA MEETING - McMaster Burke Science Building, room B148. Event Horizon - Hamilton Amateur Astronomers