Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Optical telescope wikipedia , lookup
Allen Telescope Array wikipedia , lookup
Lovell Telescope wikipedia , lookup
Reflecting telescope wikipedia , lookup
James Webb Space Telescope wikipedia , lookup
Spitzer Space Telescope wikipedia , lookup
Arecibo Observatory wikipedia , lookup
Very Large Telescope wikipedia , lookup
Leibniz Institute for Astrophysics Potsdam wikipedia , lookup
the newslette r o f th e QUEEN ELIZABET H PLANETARIU M and the EDMONTON CENTRE, RAS C JUNE/JULY 198 1 75$ •Sunset ove r La s Campanas Journey to the stars this summer at the Queen Elizabeth Planetarium A GALAX Y CD F ONE People used to believe in demons and dragons. Now these beasts have been replaced by a modem mythological creatur e — the alien from outer space. Are there intelligent beings out there? Is there life on other planets? So me recent research suggests that we may live in a galaxy of one. SUMMER STARLIGHT During the summer months people journey to far away places on their vocations. But have you eve r explored the sky above you eac h and ever y night? In "Summer Starlight" we'll point out the prominent planets , stars, and constellations visible during summer. A FANTAS Y OF STAR S A special show for special people, children ages 3 - 7, "A Fantasy of Stars" follows the adventures of Harold the Hero as he searches for Queen Cassiopeia, the only person who can sav e his planet calle d Noctophobia wher e everyone is afraid of the dark. FOR MORE INFORMATION, CALL 455-0119 Stardust JUNE/JULY 198 1 Vol. 2 6 No . 4 The Souther n Skie s o f the Ande s Kare n Finsta d This region is one of the world's best astronomical sites; the dry air and climate provid e marvefousl y clea r an d steady seeing . 12 Radio Astronom y fo r the Amateu r Dav e Beal e If you are interested in this area it can be very rewarding sinc e it is a field of investigation rarel y attempte d b y amateurs . 14 Constructing an Astrograph ...Dav e Belche r Wouldn't i t be nice to cove r one hundred squar e degree s o f the sky on a single exposur e wit h a scale o f 1 ° pe r inch ? Editor Alan Dye r Assistant Editor Sttwirt Kry»k o Contributing Editors T*d Cad!« n John Haut t Dan Holmgre n Andrew Low* Rod McConnsll Anthony Whyt e Typesetting Lorna Milllgan 2 4 6 17 18 21 23 25 The Fron t Pag e Fro Discoveries Astronom Astronomy Basic s Wher RASC New s General Meetin g Notic e At th e Planetariu m Look Bac k Tim e 5 What's Up ? Sagittariu m the Editor's Termina l y New s Update e is the Moon Tonight ? 0 and 100 Years Ago s Graphic Arts Dave Btlche r Rick Corrtga n Printed by The City Of EDMONTON Parks an d Recreation COVER: Ther e ar e a fe w location s i n th e worl d considere d the bes t site s fo r astronomical observing . One of these i s the western peaks of the Chilean Andes. The Europeans an d American s al l hav e installation s i n thi s area , a s doe s Canada . Th e University of Toronto operates a small 61cm telescope at Las Campanas. Depicted on the front cover i s a sunset ove r one o f th e La s Campanas domes. In this issue, Karen Finstad tells u s what i t i s like to observ e from that souther n latitude. STARDUST, the newsletter of the Queen Elizabeth Planetarium and the Edmonton Centre, RASC, is published bi-monthly and is available free to all members of the Royal Astronomical Society of Canada, Edmonton Centre as a benefit of membership. Single copies are available at the Planetarium Bookstore for 75c. STARDUST is also available by subscription for $4.50per year for 6 issues ($9.00 for two years for 12 issues). Please make all cheques or money orders payable to: The Queen Elizabeth Planetarium. Write to: The Editor, STARDUST; do Queen Elizabeth Planetarium: CN Tower Wtti Floor; 10004 - 104 Avenue: Edmonton, Alberta, T5J QK1. Unsolicited articles or photographs pertaining to any aspect of astronomy are welcome. From The Editor's Terminal Ihe froAl page As in previous years, the summer is once again shaping up to be a busy time for amateu r astronomers in the Edmonto n area . There i s certainly no lack of things t o do, places to go, conventions to attend, and projects to work on. For example, in this issu e you'll find details on 3 astronomical events, eac h locate d at a different "mountain. " First, i s th e annua l Summe r Solstic e Celebratio n a t Buc k Mountain. A s everyon e likel y know s b y now , perpetua l twiligh t essentially prevent s any observin g (othe r tha n luna r an d planetary work) aroun d solstic e time. Instead , we utilize ou r observin g site at Buck for a night-time campfir e gathering, weiner roast, and outdoor party. Everyon e i s invited, For mor e information, call Ted Cadien at Secondly, ove r th e Augus t lon g weekend , amateur s fro m th e Edmonton and Calgary Centres and from the Medicine Hat Club are planning t o gathe r o n top o f 8000-foot Platea u Mountain fo r 2 or 3 nights of first-class deep-sky bberving. Plateau is about 150km southwest of Calgary in the Livingsto n Range of the Rockies. The scenery alone i s wort h th e visit . Fo r mor e details , phon e Dav e Beal e a t 4740811. Thirdly, i f yo u ar e no t heading down t o Platea u on the August long weekend , why not make a trip out to Riding Mountai n Nationa l Park i n Manitoba ? Th e Winnipe g Centr e is hostin g the "Manitob a Astronomical Convention " ami d th e beautifu l lake s an d wood s of Riding Mountain . Th e skie s ar e sai d t o b e ver y dark . Fo r mor e information, contact , Gu y Westcott , Winnipeg Centre , RASC , c/ o P.O. Bo x 174 , St. James P.O., Winnipeg, Manitoba , R3 J 3R4. On to p o f al l thes e events , don' t forge t th e RAS C Genera l Assembly in Victoria June 26 - 29. See your recent issues of the RASC National Newsletter fo r information . During th e summer , wor k wil l als o continu e o n preparin g th e Buck Mountai n sit e fo r th e establishmen t o f ou r observin g headquarters ou t there . I t no w look s a s i f th e Centre wil l b e purchasing a n ATCO-style trailer uni t for placemen t at Buck, rather than constructin g a building from scratch o r from a kit. Assistanc e from Centre members on this project and on the construction of our 45cm (17.5") Dobsonia n scope would be welcome. Again, phone Ted Cadien. The last item I wish to bring to your attention is the new format for our bac k cover . I n a n attemp t t o presen t a cleare r pictur e o f astronomical activities aroun d Edmonton , I hav e switche d t o a n actual calendar , wit h meetings , observin g sessions , planetariu m show premieres , etc. marke d for a 3-month period . Eve n i f the next issue o f Stardust shoul d arriv e late , yo u shoul d stil l hav e th e information on events for tha t month . Deadline fo r th e August/Septembe r issu e i s th e Jun e 2 2 Observer's Corne r meeting . CLEAR SKIE S Alan Dye r HOURS: 8:30am-4:30pm '• i/-\f- \ i- p 6:30pm - 9:00pm lues - Sun 1:30pm -4:00pm So" an a Sur , Ph.:455-0119 BOOKS FO R THE AMATEUR ASTRONOMER: E The Star s Belong to Everyon e (Hogg) Astronomy with Binoculars (Muirden) Telescopes for Skygazing (Paul) Outer Space Photograph y (Paul) How To Read The Night Sky (Kals) Edmund Sk y Guide 1981 RAS C Observer's Handbook BurnhanYs Celestial Handbooks Vol.1 - 3 Webb Society Handbooks: Vol.1 Double Stars Vol.2 Nebula e Norton's Star Atla s Seasonal Star Charts ASTRONOMY magazin e (monthly) CARLWETZLAR BINOCULARS : 7 power x 50mm 8 powe r x 40mm MEADE 8-inch Schmidt-Cassegrain Telescope: Special Introductor y Pric e Basic Telescope Package (incl . Meade Wedge and Tripod) $' cli/coucnc/ o/tronomy" new/ updat e MOVING INT O SPAC E ? A numbe r o f recen t magazin e article s and new s items have mentioned th e risin g interest i n space and astronomy among th e general public . Thi s is , of course , becaus e o f the fantasti c results o f the Voyage r mission s and the successful flight o f th e first Spac e Shuttle, Columbia . Al l thi s pay s dividends i n increased suppor t for astronomical research both o n Eart h an d i n space. The Space Telescope i s slated to g o int o operatio n i n the mid-1980's , an d will enormousl y expan d our horizons . Add t o this th e existing orbital observatories plu s th e space astronomy programs no w i n the plannin g stage s and th e future of astronom y look s ver y promising . However, al l this lead s u s to anothe r point — telescopes ar e not th e onl y thing s about t o g o int o orbit . Th e Sola r Power Satellite (SP S for short ) i s being haile d as the ultimate solution t o th e energy crisis . What i s an SPS ? I t i s a sheet of sola r cell s several kilometers o n a side, locate d i n a 24-hou r orbit abou t 35,000k m out. It s function i s to convert sunligh t int o microwave s which are then beame d back t o eart h an d converted to electricity. That's th e goo d part ; what follows ar e the parts tha t hurt . A n SP S will b e BRIGHT. Very bright — so muc h s o that i t ma y even be visible i n the daytime . Remembe r Echo I , Skylab an d all the other larg e artificia l objects i n space? SP S will approac h the brightness of the moon in the crescent phase. What' s more, i f thing s g o a s planned, there won' t b e just on e or tw o sittin g ou t i n space, there ma y b e ten o r dozens , o r man y more. I n fact, a recent articl e i n a certain popular scienc e magazin e enthusiasticall y predicted a entire bel t of the things encircling the eart h busil y beamin g power to an energy- starved world. Wha t they didn' t mentio n were the amateu r and professiona l astronomers foaming a t the mout h becaus e they can n o longer se e the sk y — only a line o f painfull y bright solar powe r satellite s hanging over th e equator, washin g out th e stars. These prediction s may b e i n th e same class a s the "airplan e i n every garage" type that appeare d regularly i n the pul p magazines i n th e 1940' s o r the y ma y b e as inevitable a s cloud o n a Saturday night, bu t i t is alarmin g t o conside r ou r observin g activities comin g to a final, abrupt end . Move int o space ? We may hav e to. -- reprinte d from Saskatoon Skies, newsletter of the Saskatoon Centre, RASC DIAMONDS ARE FOREVER Tiny crystal s of diamon d hav e recentl y been found i n a 10.4-kg iro n meteorite collected from th e Antarctic ic e cap in 1977 . The discover y was reported i n Nature b y Ro y S. Clark e Jr., Danie l Applebaum, an d Daphn e Ross, al l o f th e Smithsonia n Institution . This i s only th e secon d iron-typ e meteorite discovere d to hav e diamond s within it . The other i s the Canyo n Diablo meteorit e whic h forme d th e mile-wide Barringer Meteo r Crate r i n norther n Arizona some 20,000 years ago. Th e diamonds withi n i t ar e believed to hav e been produced by the shock pressure of impac t when i t hit th e earth . Th e Antarctic meteorite , on the othe r hand , i s much smalle r an d would no t hav e produced sufficien t shock when it hit the earth . The diamonds in it therefore mus t b e the resul t o f som e great collision that too k plac e within th e asteroi d belt man y million s of year s ago . geological structure s for oi l an d ga s reserves, an ai r pollutio n measuremen t experiment designed t o ma p distribution o f carbo n monoxide i n the atmosphere , and a device to survey lightnin g storm s a t nigh t an d durin g the day . ANOTHER ON E BITE S TH E DUS T In mid-Augus t th e Shuttl e wil l agai n b e rolle d out , ready fo r a September 30 launch. Technicians report that Columbia was relatively unscathe d by Its maiden flight i n April. COLUMBIA'S ENCOR E Columbia's secon d flight , no w schedule d for lat e September, will b e a first — the firs t time a spacecraft has flown twice. Th e Spac e Shuttle Columbi a i s no w bac k a t Cap e Canaveral fo r refurbishing , wit h astronaut s Dick Engl e an d Richar d Truly trainin g fo r what wil l be their first spaceflight, a 4-da y mission. The payloa d for th e second Shuttl e mission i s also bein g prepared . Calle d OSTA1 (fo r NASA' s Office of Spac e an d Terrestrial Applications whic h i s providing mos t o f th e seven experiments) , the packag e will demonstrate th e Shuttle' s capabilit y a s a platform fo r scientifi c research . The experiments ar e concerned with remot e sensing o f lan d resources , atmospheri c phenomena and ocean conditions . Include d are: an imagin g rada r devic e to ma p NASA's secon d "Hig h Energ y Astronom y Observatory" o r HEAO-2 , ha s ended it s mission, it s supply o f contro l ga s exhausted. With 2 9 months o f operatio n t o it s credit , HEAO-2 performe d mor e than twic e a s long as it s desig n calle d for , a feat expecte d t o b e equalled b y HEAO- 3 whic h i s still i n operation. HEAO-2 carrie d th e world's larges t focusing X-ra y telescop e an d performe d thousands o f observation s of X-ra y stars, supernova remnants , galaxies and quasars. The forme r Observatory i s expected t o re enter an d bur n u p i n the atmospher e sometime i n 1982 . READYING TH E INFRA-RE D EY E There ha s been muc h publicit y alread y surrounding th e Spac e Telescope schedule d for Shuttl e launc h late r thi s decade . Bu t another orbitin g astronomica l telescope, one designed fo r wor k i n the infra-re d spectrum , is nearin g completion , an d wil l b e launche d in August , 198 2 via a Delta rocket. The Infra-Re d Astronomica l Satellite, or IRAS, ha s a 60cm mirror , on e capabl e o f detecting perhap s a million infra-re d sources. It will locat e thousand s o f ne w quasars, whose ligh t i s 1 1 to 1 2 billion year s ol d an d comes fro m th e earl y universe . I t will loo k into th e dust-hidde n centr e o f ou r galaxy, detect "invisible " coo l star s nea r th e earth , and i n our ow n sola r syste m locat e ne w asteroids an d possibl e ne w outer planets . Half o f the IRAS' s observing tim e will be devoted t o a comprehensive infra-re d sk y survey an d catalogue. <i/lioiiomy bo/ic / inhere i / th e moo n tonigh t ? Most readers of this column wilt be aware of the monthly cycle of the moon's phases and the cause o f thos e phases . It's a topic a littl e to o basic fo r thi s department . Bu t hav e you eve r stopped to figure out the geometry of where the moon i s in the sk y at various phases? You may know wh y th e moo n i s full; bu t d o yo u kno w where to find the full moon? Or the last quarter? Will th e ful l moo n o f summer be at a different location in the sky than the full moon of winter? Most diagram s illustratin g luna r phases depict th e lunar orbi t from a vantage point well above th e earth's north pole . We see the moon revolving abou t th e eart h a s som e spac e traveller migh t vie w it . Bu t tr y t o switc h you r vantage point to one on the surface of the earth, THIS DIAGRAM SHOWS THE SKY AS SEE N AT SUNSET ON SEVERAL SUCCESSIVE EVENING S TO SHOW HOW THE MOON TRAVERSES THE SK Y AS IT ORBITS THE EARTH. looking out into space. What do we actually see as the mont h progresses ? At ne w moon , th e moo n an d su n ar e very close t o eac h othe r i n th e sky . The y ar e i n a nearly straight lin e (only a perfectly straight line during a solar eclipse) . A s the day s go by , the separation betwee n th e moo n an d su n increases. A t th e crescen t phas e some 3 to 4 days after new, the moon is about30° -50° from the sun. In which direction? The moon iseasfof the sun . Eac h day the moo n move s about 13 ° further alon g it s orbit ; i t move s counter clockwise as seen from above the north pole, or from west to eas t as seen from earth . At first quarter, the moo n i s 90° away from the sun . Two week s after new , th e moo n ha s FIRST QUARTER € 7 Days After NE W GIBBOUS > 10 Day s After NE W CRESCENT •^Distance Abov e Horizon i n Degree s Is Moon' s Altitud e (3 Day s After NE W 90° FROM THI S DIAGRA M ON E CA N SE E THAT THE FULL MOON.BEING 180° OPPOSITE THE SUN,RISE S A T SUN SEI. TH E FIRS T QilARJEg MOON, 90 EAST OF THE SUN,I S DU E SOUTH A T SUNSET,WHIL E TH E THI N CRESCENT MOO N APPEAR S LO W I N RISING FUL L MOO N 14 Day s Afte r NE W MOO N THE WEST. THE WAXIN G CRESCEN T AND QUARTE R MOO N CA N ALSO BE SEEN A T MID-DA Y EAS T OF THE SUN SETTING SUN moved onc e agai n int o a nearl y straigh t lin e with th e eart h an d sun , but thi s time opposite the sun. It is now at full phase, 180° from the sun in th e sky . Ho w d o thes e angles translat e into what w e actually see ? —The 3 or 4-day old crescent moon is seen in the western sky after sunset, setting perhap s 1 to 4 hours afte r th e sun. —The firs t quarte r moo n i s du e sout h a t sunset, and won't se t until at least 6 hours after sunset. —The 10-da y old "gibbous " moo n i s in the south-east sk y a t sunset and wil l remai n i n the sky fo r mos t o f th e night . —The full moon , bein g 180 ° from th e sun, rises i n the east directly opposite the sun as the sun sets . Conversely , the ful l moo n wil l se f as the sun rise s th e nex t day. —The last quarte r moo n i s also 90° awa y from the sun, but to the west. The moon a t this phase rise s near midnigh t an d i s due sout h a s the sun comes up . The last quarter moon won't set unti l mid-day . Got i t s o far ? Knowin g th e angl e between the moo n an d su n i s enoug h t o giv e yo u a n approximate idea of where to find the moon and when t o expec t i t t o se t o r rise . T o b e mor e precise, however , require s a knowledg e o f where th e rnoo n i s on the ecliptic. Most people are familiar with the fact that in summer th e su n i s hig h i n th e sky , while i n winter the sun traverses the sky at a low altitude. This is due to the tilt of the earth's equator at an angle o f 23.5 ° wit h respec t t o th e plan e o f it s orbit around th e sun. The orbit of the moon also lies in more or les s the same plane as the earth's orbit. (Actually, the moon can b e as much as 5° north or south of the earth's orbital or "ecliptic" plane, bu t thi s i s not critica l t o ou r discussio n here.) I n short, the moon essentially follows the same pat h acros s the sk y a s does th e sun. But i f th e su n i s hig h o n th e eclipti c (a t a declination of+23.5° ) as it is at summer solstice time, where will the full moo n be ? Again, it wil l be 180° opposit e the sun. This place s it low on the eclipti c nea r the sun's winter solstice point (at a declination of about -23.5°). The summer full moon s ar e alway s ver y lo w i n th e sky, something t o kee p i n min d whe n plannin g fo r the July , 198 2 total eclipse of th e moon . Sum. Solstice ..-.*... N MOON ALWAY S FOUN D NEAR TH E ECLIPTI C I N STIPPLED ZON E I Eq . 360° CELESTIAL EQUATOR Just th e opposite is true i n winter. The sun is alway s a t a lo w altitude , bu t th e ful l moo n rides hig h int o the winte r nigh t sky . Now think about the first quarter moon for a moment. At verna l equinox tim e aroun d March 21, the first quarter moon wil l b e 90° east of the sun. Thi s place s i t hig h i n th e sk y nea r th e summer solstic e poin t o n th e ecliptic . Th e spring i s a good tim e t o photograp h the firs t quarter moo n sinc e i t i s nea r it s maximu m altitude fo r th e year . The sam e applies t o th e last quarter moon in the autumn season, though you'd hav e t o ge t u p earl y i n th e mornin g t o catch it . Understanding wh y th e moo n appear s where i t doe s ca n b e a difficul t concep t t o grasp; i t require s yo u t o translat e word s an d 2-dimensional diagram s t o a 3-dimensiona l sky. Bu t onc e yo u hav e th e pictur e straight , you'll b e wel l o n you r wa y t o understandin g how the sk y works . ~ Alan Dyer La Slll a I n Chil e Is home t o a large collectio n of telescope s operated b y the Europea n Souther n Observatory . La Sllla, Las Campanas, an d the Cerro Tololo Inter-American Observator y are the 3 main astronomical site s In Chile. All photos with this article by the author . The Southern Skies of the Andes Three observatorie s are locate d on the pea k o f U s Campanas — a 1-metre and a 2.5-metre telescop e operated by the Carnegie Institution, an d a .61-metr e operate d b y the Universit y o f Toronto fo r Canadian astronomers. by Karen Finstad I t take s almos t thre e day s t o trave l fro m Toronto t o the U. of T. Southern Observatory at Las Campanas, Chile. The 16-hourflightto Santiago has one stopover in Lima, Peru, and so that i s wher e I firs t se t foo t i n th e souther n hemisphere, on June 7 of last summer. Not that there is much to see in the Lim a airport at 5 a.m. local time. I spent mos t of the 2 hour wait poring over m y Spanis h phras e book . In thos e tw o hour s I had plent y o f time t o memorize many useful phrases ("I do not speak Spanish" an d "Wher e i s the washroom? " wer e my personal favorites), all of which deserted me completely on arrival in Santiago. After a rather unsettling encounte r wit h a porter , I wa s shepherded safel y to th e hote l b y Alan Boyce, U. of T. Resident Astronomer at Las Campanas, and Jos e Mazas , a former U. of T. graduate and astronomer a t the Universit y o f Chile . The followin g da y I ha d tim e t o explor e some of Santiago b y foot before the 6 hour bus ride nort h t o L a Serena, th e closes t cit y t o the observatory. It is also the location for the off ices and gues t house s o f th e America n Carnegi e Foundation's Souther n Observatory . CARSO is the prinicpl e occupan t o n La s Campanas , operating tw o larg e telescope s an d a lodge ' there. Early the next mornin g w e departed o n the final leg , anothe r lon g bu t sceni c drive , paralleling th e coast and providing lovel y views of th e ocea n befor e turnin g eas t int o highe r country. Access to the observatory i s via a winding, rocky roa d whic h enter s th e Atacam a Deser t and then climbs steeply and dangerously u p the approximately 210 0 metre s t o th e to p o f La s Campanas. Drivin g throug h th e bare , multicoloured hill s wit h th e sno w covere d Andes risin g i n th e distanc e wa s particularl y striking. Th e man y colour s (pinks , greens , violets and yellows) in the surrounding hill s was due no t t o vegetatio n bu t t o th e abundan t variety o f mineral s i n the rocks . The thre e dome s o f th e observator y ar e spread i n a ro w acros s the hummock y summi t of th e "mountain" . Th e smalles t dome i s the U. of T.' s .61-metr e (24"), whil e th e large r dome s house th e 1-metr e (40" ) an d th e 2.5-metr e {100") CARS O telescopes . Als o o n th e mountain i s th e comfortabl e CARS O lodge , containing livin g an d eatin g spac e fo r th e astronomers an d maintenanc e people . Th e U n i v e r s i t y o f T o r o n t o ha s it s ow n accommodation, know n a s Cas a Canadiense, not fa r fro m ou r dome . The Canadia n telescop e i s a 61cm Ealin g which, accordin g t o th e extensive diaries kep t at Casa Canadiense for the last 7 years, was the source o f man y headache s i n th e earl y years. However, everything ran perfectly smoothly fo r me, a t leas t mechanically . Th e weathe r wa s another matter . The seeing conditions during m y first night on the mountai n rule d out photometry , bu t the sky wa s clea r enoug h fo r som e sigh t seeing. And quite spectacular sights they were, too, for from the latitude of-29° the bright star clouds of the Galacti c centr e ar e almos t directl y overhead a t tha t tim e o f year . Th e Larg e an d Small Magellani c Clouds , th e Souther n Cross , a and /3Centauri,Scorpius, the Coalsack.the (} Cen an d ' 1 Carin a clusters , Jupiter , Mars , Saturn; eve n th e zodiaca l ligh t an d a fe w noctilucent cloud s wer e all visibl e that night . This regio n i s on e o f th e world' s bes t astronomical sites ; th e dr y ai r an d climat e provide marvelousl y clear and steady seeing — most o f th e time , tha t is . Naturally , I arrive d there i n th e middl e o f th e worst winter anyon e had eve r seen . I t actuall y raine d 2 o r 3 times during m y run , whic h i s quite unhear d of . In between the fog and the clouds I had less than a handfu l o f photometri c nights , an d a s many agai n w h i c h wer e suitabl e fo r spectroscopic observations . Needles s t o say , my photometri c progra m o f Cephei d variabl e observations barel y go t of f th e ground . Bu t every cloud, i f you'll forgive the cliche, brings a silver lining , o r a t leas t a golden sunset , and I did se e some grea t ones . An d o n th e clearest days whe n th e atmospher e wa s ver y steady, sunset on the sharp horizon line of the ocean 80 km away provided perfec t conditions fo r seeing the Gree n Flash . This i s a rare atmospheric effect caused by refraction o f th e sun' s imag e int o severa l overlapping images of different colours with the green imag e o n top . (Th e blu e wavelengths have bee n scattered by atmospheric particles. ) At th e las t instan t befor e th e su n set s completely belo w th e horizon , th e uppermos t green ri m become s visible for a few seconds . I * was able to see the Green Flas h on half a dozen occasions, bu t i t i s a difficul t effec t t o Casa Canadiens e I s the smal l residence buildin g for Canadian astronomers usin g the .61-metre U . of T. telescop e at La s Campanas. 10 The exterio r o f th e 3.6-metr e telescop e a t th e European Souther n Observator y a t L a Sflla , Chile. The 3.6-metr e ES O reflector , a n Impressiv e telescope use d b y a consortium o f 1 0 nations. photograph, and al l o f m y attempt s failed. During m y 3 wee k observin g run , a succession o f astronomer s usin g th e CARS O telescopes came and went. The 1-metre is used very often for infra-red observations and was all but burie d i n cryogeni c coolin g equipmen t when I saw it. The 2.5-metre Dupont telescop e is a beautifu l instrument , an d it s optic s an d mechanical desig n ar e amon g th e bes t anywhere. I wa s show n a contact prin t mad e from on e o f th e hug e photographi c plate s (about 5 0 c m square , f think ) take n wit h thi s telescope which ha d undistorted stellar images almost t o th e very edge of th e plate . Practically "next door " to Las Campanas is the saddl e shape d pea k o f L a Silla, site o f th e European Souther n Observatory . It s larges t dome, housing the 3.6-metre, is just visible as a white spec k fro m Campanas . On e afternoon I drove ove r wit h anothe r visitin g graduat e student, Mathe w Malka n fro m Caltech . Operated jointl y b y abou t 1 0 Europea n countries, ES O i s a mos t impressiv e place . There i s a smal l villag e a t th e bas e o f th e mountain fo r maintenanc e crews, and another at the top for visitin g astronomers and resident scientists an d technicians . Th e optica l collection includes , beside s the 3.6-metre, two 1.5-metre telescopes, 8 or 9 smaller telescopes of various sizes and purposes, and one contact lens, whic h I managed t o los e during th e tour. The Universit y of Toronto's observator y in Chile i s unquestionabl y a valuabl e an d productive researc h instrument . However , the University i s no w strugglin g t o kee p u p th e operation i n th e fac e of drasticall y increasin g costs. I t i s to b e hoped tha t th e facilit y wil l b e available t o Canadia n astronomer s fo r a lon g time t o come , an d tha t othe r student s lik e myself wil l continu e t o b e offere d th e opportunity t o wor k there . Bu t I wis h the m better luc k wit h th e weather. 11 Radio flstronomu for th e flmateur by Dave Beal e L et's take a look at the prospects for amateur observations in the radio spectrum. To be successful i n jus t detecting objects , th e amateur must : 1. construct o r bu y relativel y large antennas 2. construct o r bu y ver y sensitiv e electronics 3. operate the abov e i n isolate d areas. The majorit y o f radi o object s hav e signal strengths o f onl y a few "Janskys" (1 Jansky = 10-24 w/m2/Hz). I f a 10 metre diameter parabolic reflector i s constructed t o operat e at 150 MHz, we coul d expec t t o receiv e fro m a n averag e celestial source, 10~ 16 Watts. Ordinary receivers wouldn't notic e this low signal level , since they have typical "nois e floors" o f about 1O' 15 Watts. The objects observabl e b y amateur equipmen t are listed in the Observer's Handbook. These ar e the mos t powerfu l objects . Fo r the deep-sk y source s on th e list , th e amateu r should b e well-verse d i n radi o electronics , antenna fundamentals, and should be willing to spend amount s o f money equivalen t t o buyin g optical equipment. I f you ar e interested i n this area i t ca n b e ver y rewardin g (jus t t o detec t something ! ) since i t i s a field of investigatio n rarely attempted by amateurs. Little or no useful work assistin g professional s ca n be seen her e IS for now , however. Equipment ma y be purchased (see Sky and Telescope fo r sources ) or can b e found on the surplus market s an d modified . Du e t o th e specialized needs, however, the best route is to build everythin g yourself. The most promisin g methods for amateurs i s to operate below about 5 GH z (500 0 MHz ) usin g th e bes t affordable converter an d a n inexpensiv e commercia l receiver modified fo r bandwidth and detection. The converte r would contai n a ver y expensiv e RF amplifier (abou t $500 for parts ) followed by a loca l oscillator , probably crysta l controlled, and multiplie d u p t o th e require d frequency. The goa l i s t o conver t th e receive d signal t o some lowe r frequenc y tha t i s no t normall y occupied b y a stron g transmitter , bu t i s accessible wit h a commercia l receiver . I t i s possible t o coo l th e converter ; however great care mus t b e t a k e n du e t o th e expansioncontraction effects , eve n insid e components. I t mus t b e emphasize d tha t th e major portion of the project's expense and work will b e involved here. The antenn a can , o n th e othe r hand , b e constructed fro m scratc h an d eve n a n interferometer ca n b e easily built (se e Sky an d Telescope 1978-79) . The output of the receiver may b e listene d to , measure d an d manuall y recorded, o r connecte d t o a strip-char t recorded. But , the antennas are the most fun to contruct, sinc e ther e i s no t s o muc h engineering required. I recommend a parabolic dish fixed on the ground with only the elevation adjustable, lettin g th e Earth' s rotatio n swee p the sk y i n azimuth . I t shoul d b e a s bi g a s possible t o giv e you r electronic s a fightin g chance, bu t b e carefu l t o kee p i t reasonabl y rigid. Accurac y o f 1/8t h wavelengt h would b e fine (1cm at 2700 MHz). The dipole pickup must be more accurately positoned a t the focal point of the dish (±1/10 wavelength or better) and can be accomplished whil e monitorin g th e output. What you will endupwithisan increase in static when observin g mos t objects , bu t eve n thi s result ca n b e quite satisfyin g fo r th e die-har d radio astronom y fan . For those wanting to do potentially "useful" work, ther e ar e a t leas t two possibilities . The above electronics ma y be constructed a t lowe r cost with less sensitivity an d used with a smaller dish tracking the sun in a "solar patrol " mode to warn o r lear n o f sola r flare s an d long-ter m cycles. Th e frequenc y ma y b e chose n afte r careful consideration of the literature. It may be more usefu l to pic k a frequency not monitore d by others. The secon d projec t involve s a n are a w e specialize i n — aurorae . I n th e October , 198 0 issue of the Journal o f th e R.A.S.C. Coli n Kea y published a n articl e title d "Audibl e Sound s Excited b y Aurorae and Meteor Fireballs." The mechanism of this phenomena is not a t present well understoo d an d i s stil l controversial . However i t involve s th e "crackling " o r hissin g sounds heard sometimes during brightfireballs or spectacular auroral displays. Keay propose s VIRGO A antenna i s directiona l alon g th e plan e o f th e loop. Wit h thi s setup , whistlers , th e "daw n chorus", an d other natural phenomen a ma y be detected. Th e earth' s ionospher e act s a s a shield, however , so no extra-terrestrial sources will b e heard . Everythin g hear d come s fro m below th e ionosphere . Because this equipment i s so simple, small, and powe r efficient , i t i s actuall y a portabl e radio telescope . Also, th e natura l phenomen a heard ca n b e quit e beautifu l an d interesting , certainly mor e audibl y uniqu e tha n mer e hiss and static . Th e whistler s ar e though t t o b e caused b y lightnin g radi o energ y bouncin g back an d fort h betwee n th e eart h an d f = 238. 5 MH z Jan. 30 , 198 1 The tracing wa s acquired by amateur astronomer s of the Ottawa Centr e o f the RASC using their interferomete r Installation at their Indian River Observatory Site. It records th e powerful radio source Virgo A, known to optical astronomers as the galax y M87. Reprinte d fro m AstroNotes, th e newslette r of the Ottaw a Centre, RASC . that the "sounds" are generated by radio energy in th e VL F o r Ver y Lo w Frequenc y spectrum , particularly aroun d a frequenc y o f 8 KH z — audio frequenc y radio waves ! A receiver at this frequency become s ver y eas y t o construct , consisting o f a filte r ( t o remov e 60 H z power line hu m an d a cut-of f uppe r bandwidt h t o about 1 2 KHz), followe d b y a high gain audi o amplifier feedin g a detector an d speaker. The detector woul d b e connecte d t o a char t recorder o r mete r fo r recordin g data , th e speaker merel y fo r monitoring . The antenn a fo r suc h a devic e woul d b e rather unique . A conventional half-wav e dipole would b e almost 19k m long! Instead, we take a large diamete r (1/ 2 inc h o r so) conductor an d make a n 8 t o 2 0 tur n loop , abou t 1 metr e i n diameter. Th e conducto r ma y b e hollo w bu t should b e very conductive . Aluminu m ca n b e used bu t coppe r i s better . Th e outpu t ma y be taken fro m th e tw o end s o f th e loop . Thi s ionosphere. Th e dawn chorus, as I understand it, is a plasma event generated in the ionosphere by th e change s induced b y sunlight strikin g it . Both thes e phenomen a wer e recorde d a t Jupiter an d Satur n b y the Voyager spacecraft. With luck , th e hissin g an d cracklin g o f th e aurorae an d o f bolide s ma y als o b e detected . "Listening" fo r meteor s woul d b e bes t undertaken i n conjunctio n wit h naked-ey e meteor-watch patrols . In conclusion , whil e radi o astronom y requires knowledg e i n field s othe r tha n thos e normally persue d b y amateu r telescop e makers, an d require s operating at the limit s of detection ability , th e reward s ca n b e jus t a s great a s i n optica l astronom y — and for now , more unique. Observing can be done whenever it is convenient; yo u don't have to be a nightow l or dependen t o n th e weather , almos t reaso n enough t o tak e u p radi o astronomy ! Good observing . 13 Consi Two histori c astrograph s have seen a great deal of use : ABOVE is the Metcaif 40-c m astrograph a t the Harvar d Observatory's old Agassl z Station . AT LEF T Is the double astrograph o f Lick Observatory . It s twin 50-cm lenses are used to tak e simultaneous photos I n two colours. 14 ructing an Astrograph by Dave Belcher I t ha s bee n th e drea m o f man y amateu r astronomers t o emulat e th e photographi c work o f the world's grea t observatories such as Palomar, Lick, and Kitt Peak. It would appear that many of these amateurs are now producin g photographs tha t indee d begi n t o riva l thos e taken b y th e gian t telescopes , as witness th e works o f Be n Mayer , Everei d Kreimer , an d Canada's own Jac k Newton . These not-so-amateu r amateur s ar e combining today' s fas t colou r emulsion s wit h the mos t exoti c technique s t o obtai n magnificent photograph s o f al l th e Messie r objects and many of the N.G.C. objects, targets once thought of as next to impossible t o recor d in shor t exposure s wit h amateu r telescopes . However, mos t o f thos e telescope s produce thei r image s o n a piece of fil m that is only 2 4 by 36 millimetres (35m m film), which in most cases represents an area of the sky of 1 ° or less. I n orde r t o cove r eve n th e norther n celestial hemispher e a t thi s rate , i t woul d r e q u i r e mor e tha n 20,00 0 s e p a r a t e photographs. Wouldn' t it be nice t o cover, say, one hundre d squar e degree s o f th e sk y o n a single exposure with an image scale of 1 ° per inch, usin g a telescope of onl y eigh t inche s i n aperture? Enter , the astrographic camera. The astrographi c telescope-camer a represents a n importan t researc h tool , fo r i t enables the professiona l astronome r t o obtai n photographs o f larg e area s o f th e sky , even larger tha n thos e obtaine d wit h Schmid t cameras. Fro m thes e larg e plate s h e can sca n the image for objects that can be photographe d in greate r detai l an d large r scal e wit h th e bi g telescopes. Most o f th e majo r observatorie s hav e astrographic telescope s fo r makin g broa d sk y searches. Th e mos t famou s i s th e Carnegi e double astrograp h a t Lic k Observatory . I t consists of two 50c m diameter lense s mounte d in tandem . On e camer a i s loade d wit h redsensitive emulsion , th e othe r wit h bluesensitive. Simultaneou s exposure s o f th e same are a o f th e sk y ca n the n b e obtained a t different wavelength s and then compared . Th e Carnegie astrograp h i s on e o f th e world' s greatest galax y hunter s an d i s als o use d t o determine th e prope r motion s o f stars . Othe r notable astrograph s includ e th e 33c m Lowel l astrograph a t Flagstaff , Arizon a (o n whos e 11 Elements o f a n Astrograp h EASTMAN KODA K LEN S AS SEMBLY, f/6.3 , 48" f.I. This was used wit h the K-40 aerial camera, which takes a 9" x 18" plate. Approximate dimensions : 14" diameter x 26 " long. Contain s iris . Lense s mounte d in aluminum housing . Approximat e weigh t o f unit - 12 5 Ibs. The astroqraphi c camer a Dav e Belche r i s building wil l us e th e len s advertise d abov e Just .i s importan t a s th e optic s i s th e mount , and Dav e ha s chose n th e massiv e for k moun t from Astf O Work s depicte d belo w Tha t i s not Dav e standin g besid e i t II 1t plates Pluto was discovered i n 1930) , the 60cm Bruce telescop e use d i n Sout h Afric a b y Harvard Observator y t o sca n th e souther n skies, an d th e Metcal f 40c m double t a t Harvard's Agassi z station. Any camera , onc e i t i s pointed t o th e sky, becomes a n astrograph . However, i n orde r t o obtain larg e scale photographs on large plates , the camer a require s a bi g len s wit h grea t covering powe r an d a flat field. Proces s lenses which ar e perfectl y colour-corrected , extremely shar p an d ca n cove r plate s as large as on e mete r squar e wit h a foca l lengt h o f 1800mm woul d b e ideal, except for one serious drawback — they ar e very slow, usuall y f/ 9 t o f/16. Hence , th e aeria l camer a lens . The astrograp h whic h I a m presentl y constructing wil l emplo y a ver y larg e len s system use d i n th e K-4 0 aeria l camera . Manufactured b y Eastma n Kodak, the len s has a foca l lengt h o f 48 " o r 1220mm , ha s a n effective aperture o f f/6.3 an d can cover a plate of 9 by 1 8 inches. Th e len s weighs in at a hefty 125 pounds, and i s available as a surplus item from C & H Sales in Pasadena for less than $500. Holding an d guidin g thi s muc h mas s requires a very sturdy mount . T o this end I have opted for th e 30cm (1 2 1/2") Astro-Work s fork mount. Suspende d betwee n the fork s will be a cradle structur e fo r th e gian t len s plu s a platform abov e fo r othe r cameras . Mounte d beside th e bi g len s will b e the Questa r 7 barrel assembly whic h wil l b e used fo r guiding . Initially, I would lik e to us e the astrograph to compile a large scale photographic sk y atlas on plate s o f 8 b y 1 0 inches , givin g a fiel d o f about 7° by 9° on each. This project is expected to take 3 to 4 years. In addition, m y sky-search program wil l includ e come t hunting , asteroi d photography, an d galax y searches , as wel l as what I hope will b e some excel lent photograph s of th e Milk y Way . Not t o b e outdon e b y th e Edmonto n Centre's ow n 45c m Dobsonia n telescope , I would lik e t o emplo y th e len s as a Super Ric h Field Telescope , usin g a giant Ploss l eyepiece of 55m m foca l length . Wit h a magnificatio n o f 22.5x an d a fiel d o f vie w o f 2.75° , i t shoul d provide view s of the heavens that are absolutely entrancing. Completio n i s schedule d fo r lat e this summer . I can hardly wait . ici/c new / Planetarium an d from the Edmonto n Centre. Your effort s wer e no t i n vain! THE 2nd ANNUAL RAS C AWARDS On Saturday , March 21, the Edmonto n Centre hel d its annual Banque t an d award s night. A n excellen t talk o n 'Quasars , Sputniks and th e Continenta l Drift' wa s presented by Dr. Ed o Nylan d o f th e U . of A . Ted Cadien, presente d th e Centre' s series o f award s in recognitio n o f meritorious achievement durin g th e previou s year. The award s were as follows: Two view s o f STARNIGH T '81 , a cloud y bu t stil l crowded event. '• ASTRO—PHOTOGRAPHER O F THE YEAR : Dave 6ea/e,fo r hi s excellent results in piggyback an d prim e focus deep sky photography. OBSERVER O F THE YEAR : Andrew Lowe, for hi s continuing progra m of deep sk y an d occultation observing, includin g his marvelous work i n computer analysi s of eclipses, occultation an d planetary position . ANGUS SMIT H A W A R D (TELESCOP E MAKING): Mark Leenders, fo r hi s construction of a 15 cm (6" ) f/1 0 refractor. 6 OUT O F 8 ISN'T BAD Starnight '8 1 over the weeken d of Ma y 8 and 9 was a bit o f a washout thi s year , wit h clouds bot h night s preventin g an y observing. Nevertheless, 700 people turned out , viewed the RAS C and QE P exhibits and looke d a t the few telescopes tha t wer e available. On e ca n sa y i t was a qualifie d success. Thi s i s only th e second tim e i n the 8 Starnights hel d since 197 4 that the even t has been clouded out, a n excellent record . We thank everyon e wh o assiste d wit h this year's Starnight , bot h from th e rank s of th e PRESIDENT'S AWARD: Alan Dyer, fo r service to th e Centr e as editor o f Stardust, and i n hi s other officia l position s wit h th e Centre over th e pas t fe w years . UPDATE O N BUCK After lookin g a t all the various possibilities, th e group workin g o n the Buc k Mountain sit e development ha s concluded that a n ATCO-style trailer uni t woul d b e the most suitabl e structur e for Buc k a s the Centre's observing hut . Th e cos t o f a used trailer i n the 1 0 x 25 ' range , includin g transportation costs , i s within ou r budget . This saves us the wor k o f buildin g a structure 17 from scratch , though som e interio r wor k ma y still b e needed , plu s th e preparatio n o f a suitable pa d area. THE HOWEL L DONATIO N John Howell , a member o f th e Calgar y Centre, who ha s been livin g i n the Breto n area fo r th e pas t fe w year s (nea r Buc k Mtn.) , has expressed the desir e to donat e a n observatory dom e an d massiv e fork moun t for a 40 cm telescop e t o th e Centre . Thes e were a t John's acreag e near Breton , bu t a move t o th e wes t coas t ha s forced hi m t o dispose o f thes e items . A s o f thi s writing , Centre member s hav e no t see n th e dom e an d mount, bu t will likel y gladl y accep t th e donations fo r possibl e futur e us e at Buck . THE MA Y MEETIN G Once again , we wer e unabl e t o hea r fro m Dr. Phi l Curr y a t our Ma y Genera l Meeting , as Dr . Curr y wa s called ou t o f tow n unexpectedly. W e thank Joh n Hault , Projec t Manager fo r th e Edmonto n Spac e Science s Centre fo r steppin g i n a t the las t minut e wit h an excellen t talk o n th e ne w planetariu m facility. The las t Genera l Meetin g fo r th e curren t season wil l b e Monday, Jun e 8 , although th e monthly Observer' s Corners wil l continu e through Jul y an d August. The nex t issu e o f Stardust fo r Aug./Sept . will contai n mor e informatio n o n RAS C events i n lat e summer an d earl y fall . OTICE o f GENERA L MEETING S MONDAY, JUNE 8 Dr. Chris Pritchard , U. of C. MONDAY, SEPTEMBER 1 4 topic to be announced "The Canada France Hawaii Telescope" Dr. Pritchard I s wMi the University of Calgary Physics Dept. and his area of research Is galaxies and cosmology. Dr. Pritchard will talk on his experiences observing wrdi the 3.6-metr e CF H telescope on Maun* Ke a In Hawaii. We'v e heard talks on how the telescope was constructed, now well hear more about what It Is like to actuall y use It. Dr. Pritchard I s our annual exchange speaker from the Calgary Centre. Deadlne for the Aug./Sept. Issue of Stardust Is Monday, Jun e 22 . Both meeting s at : 8:00 PM ; MUSI C ROOM , EDMONTO N PUBLI C L I B R A R Y Guests an d member s o f th e publi c ar e welcom e 11 the fourth annual ' summer solstice CELEBRATION TO GET T O BUCK: TRAVEL WES T O N HWV 3 9 THROUGH CALMAR , THORSBV & WARBURG . TUR N SOUTH (LEFT ) ONT O HWY 1 2 AT ALSIKE . TRAVEL T O BRETON. JUS T SOUT H O F BRETON, TUR N WES T (RIGHT) ONT O PROV . 5ECONDARV ROA D 616 (BUC K CGEEKC9AD}. TRAVE L !7.5KM (HMD. TURN SOUTH (LEFT), 6 0 5.9K M (3. 7 Ml.) TO TH E ENTRANC E ROA D T O SITE O N TH E EAS T SID E O F THE MOUNTAIN. DRIV E I N ON THE DIRT ROAD . fit Buc k mountain, Saturday* June 20 starting at 9:oopm EVERVONE I S INVITE D TO THIS ANNUAL EVENIN G OF MERRIMENT. BRING VOU R OW N FOOD AN D REFRESHMENTS. THER E WILL BE LOT S OF WOO D FO R THE CAMPFIRE. FO R MORE INFORMATION , PLEAS E PHONE TED CADIEN AT OR . MAP S WIL L B E AVAILABLE AT TH E JUNE GENERA L MEETING. 10 *A *B WEEkEN d o f dEEp'sk y obsERviN q AT AN AlmudE of OVE R 8000 fEET , WIT H MEMBER S of TH E ECJMONTO N ANd CENTRES AN d o f TH E McdiciN E HA T Club I N E pREpAREd fo R A WEEkENd o f SElf'SuffiCJEN T pRJMITJV E CAMpJNq UNdE R VERy dARk fklES. IT CAN qET QUJTE COOl A T NJqH T A S WEll! it FO R MOR E JNfORMANON , O R fo R dJRECTIONS , plEAS E pHON E DAV E BEA U A T AVAJUbU A T ThE O.C . MEETJNq S pRJO R T O Th . MApS SHOUl d at th e planetariu m Our curren t featur e production Death o f the Dinosaurs continue s it s popula r ru n unti l Sunday, Jun e 14 . Beginning Tuesday , June 16 at 8:00 pm an d runnin g unti l the Labou r Day weeken d in September , will b e ou r perennial summe r classic, Summer Starlight. This progra m i s a liv e lecture o n th e stars , constellations an d feature s of th e summer sky. However , this sho w i s our secondary program fo r th e summer . Beginnin g Friday , June 2 6 at 8:00 pm i s our ne w majo r feature, A Galaxy o f One. This wil l ru n throughou t the summe r month s a t 3 pm an d 8 pm every day {includin g holidays) , with Summer Starlight revertin g t o a 9 pm slot . A Galaxy o f On e ha s bee n writte n fo r u s by Pau l Deans , no w o f th e Mclaughli n Planetarium staf f i n Toronto. Th e progra m looks a t the possibilit y o f extra-terrestria l life. Same old stuff, you say ? Not so , becaus e this show take s the stan d that lif e elsewher e i n the galax y ma y no t b e so abundan t afte r all. Although th e questio n i s by n o mean s settled, some ne w research ha s suggested that the developmen t o f life on earth ma y have bee n a more uniqu e occurenc e tha n previously assumed . While we are not out t o convince anyon e o f an y give n theory , w e are attempting to giv e equa l time to the 'antiSagan' point o f view . Despite what Car l says, there ma y not b e 'billions upo n billions ' o f civilizations ou t there ! The Planetarium's community astronomy programs hav e also bee n goin g stron g lately. From Januar y 1 to Apri l 30 , a total o f 420 people hav e attended one o r mor e of Stewart's astronom y courses , seminars , o r special talks. Durin g th e las t week of April , a series o f noon-hou r 'brow n bag ' astronom y talks wa s presented, wit h abou t 2 5 peopl e attending each lecture . Oddly enough, the 'straight' talk s on Voyage r and the Shuttle were mor e popular than the talks on pseudo science topic s lik e UFO' s and the Jupite r Effect. Starting Tuesday , June 1 6 for 3 consecutive Tuesday's , Stew wil l b e runnin g a Telescop e User' s Course at the AC T Recreation Centre , Contac t th e Planetariu m for mor e information . For one wee k every mont h durin g July , August, September, and October , we'll be organizing public observin g session s at the Planetarium. Thes e will ru n o n eac h of th e following nights : Tuesday, July 6 to Monday , Jul y 12 Tuesday, Augus t 3 to Monda y Augus t 1 0 Tuesday, Sept . 1 to Monday , Sept . 7 Tuesday, Oct . 6 to Monda y Oct . 1 2 As with las t summer' s sessions, we'l l b e asking fo r voluntee r hel p fro m RAS C members t o hel p ma n telescopes, an d to perhaps se t u p their ow n scopes . Again , contact Ste w at the Planetariu m a t 455-0119 . There hav e been a number o f staff additions an d changes lately . Gart h Fitzne r and Jan e Micke y hav e been hire d as part time lecturers , Jane Harric k i s our ne w typesetter an d librarian, while Ric k Corrigan , planetarium artis t (wh o lef t to atten d a film animation schoo l i n Toronto), ha s been replaced b y Sharo n Dunnigan . I n addition , Ted Coldwell, planetarium photographe r since 1975 , will b e departing fo r Nov a Scotia in July; his replacemen t ha s yet to b e named. The desig n o f th e Spac e Science Centr e is progressing very well. The Zeiss Jena sta r projector ha s been ordered ; we hop e t o hav e more-details o f the Centre' s progress i n th e next issu e of Stardust, includin g some architectural drawings of the revise d design . 21 WINNIPEG CENTR E MASCOIN 1981 MANITOBA ASTRONOMICA L CONVENTION . RIDING MOUNTAI N NATIONA L PARK . FRIDAY, JUL Y 3 1 t o MONDAY , AUGUS T 3 For mor e informatio n concernin g th e programme , accommodation . fees. etc. . write t o Gu y Westcott . c o Winnipe g Centre . P.O . Box 174. St . Jame s P.O. . Winnipeg. Manitoba . R3 J 3R 4 (Phone 204-269-149 9 afte r 6 pm ) look boc k lim e JUNE, 1931 : "Astr. Jour., No . 957 contains articles by P. van d e Kam p o n th e distanc e o f th e galacti c centre an d th e thicknes s o f th e galacti c absorbing layer . Th e thicknes s o f th e laye r i s given a s 210 parsecs, with a probable erro r o f 40. Th e distanc e of th e centr e of th e galax y is found fro m (1 ) th e centr e o f th e syste m o f globulars clusters , (2) fro m a stud y o f cluster type variables in a Milky Wa y field, (3) from the constants o f galacti c rotation . Th e extrem e values o f the distanc e o f th e centr e i n parsecs are 16,70 0 an d 7,000 . H e suggests 12,00 0 as a mean (sa y 40,000 light years). " • JULY, 1931 : "Mr. K . Hirayama, o f Toky o Observatory , investigates i n Proc . Imperial Acad. Japan th e effects o f th e impact o f a star with a spherical nebula. Th e relativ e velocit y i s probabl y hyperbolic befor e impact, but it may be reduced by th e impac t belo w paraboli c value , in which case there wil l be repeated impacts , which wil l result i n th e captur e b y th e sta r o f par t o f th e matter o f th e nebula , whil e th e star' s orbi t relatively t o the nebul a will be reduced i n size. The autho r suggest s tha t th e nebul a migh t i n time b e so reduced an d broken u p as to form a system of planets revolving around the star; this is an alternative to the theory tha t explains the formation of planets by the tidal action o f a star passing nea r th e sun. " JUNE, 1881 : "To th e studen t o f scienc e wh o contemplates th e su n b y da y o r th e star s b y night tw o question s wil l inevitabl y occur . The first wil l hav e referenc e t o th e sourc e fro m which thos e vast s orb s hav e derive d thei r stupendous stor e o f high-clas s energy ; th e second to the astonishing regularit y wit h which they ar e able to giv e it out. We ask then, i n the first place , fro m wha t sourc e ha s thi s inconceivably vas t stor e o f energ y bee n derived? Th e onl y hypothesi s ye t though t o f that can account for it is that which first occured to Maye r an d Waterson... . Accordin g t o thi s hypothesis w e ma y imagin e th e particles o f matter, when originally produced, to have been at a great distanc e fro m eac h other . A s thes e particles graduall y came togethe r in virtu e of their mutua l attraction , hea t woul d b e generated i n th e condensin g mass , and it has been calculated tha t this cause, by storing up a vast amoun t o f hea t i n th e sun , i s sufficient t o account fo r it s wonderfu l outpourin g o f hea t and ligh t throughout a long series of ages. " -- complied by Tony Whyt e Tor FOR SALE : 20c m (8" ) f/ 6 Mead e mirror , 1.83" secondary mirror, fiberglastube, plus 6x30 finderscop e and homemad e wooden mirror cei l for abov e mirror. All less than 1 year old . $130 . Phon e Dir k Auge r a t NOTICE — STOLEN TELESCOPE : The Quee n Elizabet h Planetariu m wa s recently broke n into . Stole n wa s 1 Edmund 6 " (15cm) f/6 equatorial Newtonian telescope on a pedestal mount. Any information regarding this unit will b e appreciated. Phon e Ste w Krysko at the Planetariu m a t 452-9100. 23 The distinctive "teapot" shape of Sagittarius stands out amid the rich star clouds of the Milky Way. Unfortunately, this area of thi sky just clears the southern horizo n from our latitude and Is not well seen. This photograph was taken from the 4000-foot level o Mt. Hopkins , sit e of the Multipl e Mirro r Telescope , nea r Tucson, Arizona. I t I s a 20-mlnute exposure at f/2 o n Fuflchrome 40C — phot o b y Alan_py e 24 up ogittariu/ Sagittarius lies in the direction of the centre of our galaxy. Within this wide expanse of th e Milky Way are some of the brightest star clusters and nebulae in the entire sky. From our northern latitude a very clear dark sky and an unobstructed southern horizon Is needed to observ e an y o f this month' s objects well. ** CLAS S I OBJECTS ** Bright, easy to find MB, the Lagoon Nebula is one o f the finest nebulae in the sky . It i s located northwest of A Sagittarius whic h mark s the tip of the 'tea pot'. From a dark site, it appears as a fuzzy patc h t o the unaide d eye , an d i s reveale d as a glowin g expanse o f ga s i n a pai r o f binoculars . I n a n amateur telescope it appears as a fine irregular nebulosity surroundin g th e open cluste r NG C 6530. Th e tota l diamete r of th e Lagoo n i s over 1/2° s o a low power eyepiece is needed to see it well. Th e nebul a i s cu t almos t i n hal f b y a prominent dus t channe l abou t 2 ' i n width . Although i t i s a frequently studie d object, the distance t o M 8 i s stil l relativel y uncertain . Estimates hav e range d fro m 300 0 to 5150 light years. I f w e assume it is about 5000 light years away, then it s size works ou t to at least 60 x 44 light years . About 1.5 ° t o th e northwes t i s anothe r bright nebulou s patc h calle d M2 0 th e Trifl d Nebula. I t ha s been suggested tha t M20 is part of th e sam e vast syste m o f nebulosit y a s M8 . The Trifi d consist s o f a larg e brigh t nebulou s patch divided int o three irregular areas by three distinct dar k lanes . These dark spoke s appear to radiate from a bright triple star HD 40. These dark lane s are visible in a 15 - 20 cm scope. The full exten t o f thi s nebul a i s abou t 25 ' i n diameter. A s wit h M20 , thi s distanc e t o M 8 is uncertain, wit h estimate s rangin g fro m 174 0 light year s to 6060 . ** CLAS S II OBJECTS ** Fainter, but distinctive Class I I start s ou t wit h a pair o f globula r clusters NG C 652 2 an d 6528 . The y ar e reasonably easy to locate, as they are located in the sam e fiel d a s y Sagittarius . The y ar e magnitudes 10. 5 and 1 1 respectively, and bot h are compose d o f star s o f aroun d 16t h mag . They'll be pretty close to the horizon. NGC 6645 is a fairly large, rich open cluster located just south o f the constellation Scutum . More precisely , it s abou t hal f wa y between 7 Scuti and M25. It is about 10 ' in diameter and is made u p o f abou t 7 5 stars. ** CLASS III OBJECTS ** Challenge objects Class II I thi s mont h i s occupie d b y on e object, NG C 6822 . Thi s large , faint , irregula r galaxy i s a member o f th e 'Loca l Group'. I t is situated i n th e northeas t corne r o f Sagittariu s and i s located in the sam e field of vie w as the planetary nebul a NGC 6818. This planetary is a very bright bluis h object and is easily seen, but nearby 682 2 i s very difficult . I t i s calle d Barnard's Galaxy , afte r it s discovere r E . E . Barnard. The object i s very large and diffuse; it requires lo w power, preferabl y wit h a rich-field telescope. No one has yet seen it from Buck, but Dave Belche r report s sightin g i t fro m Platea u Mountain and Darrell Cros s has spotted i t from Mount Hopkin s nea r Tuscon, Arizona. DEEP-SKY OBJECT S Constellation Chart courtesy of Hubbard Press OBJECT TYP E MAG . Class I M8 ,M20 EN E/RN Class II NGC 6528/6522 G C 11/10. NGC 664 5 O C9 Class III NGC 6822 G-Ir r1 1 Barnard's Galax y G- Galaxy Open Cluster ....Globular Cluster .- Emission Nebula Reflection Nebula + Hubble type the /olo r /y/te m THE SUN: The sun reaches its summer solstice point a t 5:45 am MD T o n th e mornin g o f Jun e 21. Eart h i s a t it s furthes t poin t fro m th e su n (aphelion) o n July 3 . On July 31 there will b e a total eclipse of the sun as seen from Siberia and the Pacifi c Ocean . This will b e seen as a slight partial eclipse in the North-West Territories and extreme northern B.C . and Alberta. (Now where did I put tha t piec e o f welder' s glass?) otherwise brilliant dis k of the full moon, but no reddening o f th e shade d portio n wil l likel y be visible. Umbral eclipse begins at 9:25 pm MDT, July 16 , and ends at 12:08 am MDT, July 17. The moon wil l b e i n th e penumbra l shado w fo r approximately 1 h 20 m befor e an d afte r thes e times. See the Summe r 197 9 issue of Stardust for informatio n o n ho w t o photograp h luna r eclipses. THE MOON : A partia l luna r eclips e wil l b e visible from our part of the world on the night of July 16-17 . At mid-eclipse, 55% of the moon's disk wil l b e in the earth's umbra l shadow . Thi s will produc e a noticeabl e "bite " ou t o f th e MERCURY: I t i s visibl e lo w i n th e wes t a t th e beginning o f Jun e afte r th e mos t favourabl e evening elongatio n o f th e yea r o n Ma y 26. Its morning appearanc e i n mid-Jul y is , however, not very suitable fo r norther n observers . 5 VENUS: It is beginning t o appear intheevening sky, and by the end of June it is near Castor and Pollux lo w in the west. Its phase is gibbous. By the end of August, Jupiter an d Saturn will have joined Venu s low i n the western sky at sunset. MARS: Durin g Jun e an d July , Mar s i s a 2n d magnitude mornin g object , movin g throug h Taurus int o Gemini. JUPITER: Jupite r continue s t o b e prominen t throughout Jun e and July, with Saturn nearby. By mid-August , Jupiter wil l b e very low i n th e south-west. SATURN: I n Virg o alon g wit h Jupiter , Satur n remains visibl e in the west until Septembe r or so. Th e ring s ar e no w incline d t o ou r lin e of sight b y about 6° . Jus t whe n you thought yo u had theSaturnian system of moons figured out, Brad Smith of NASA's Lunar and Planetary Lab reports th e discover y o f stil l mor e satellites . 1981 S 1 and 198 1 S2 have been found orbiting the plane t a t th e L 4 and L 5 libratio n point s o f Tethys, abou t 60 ° precedin g an d followin g Tethys i n it s 1 d 2 1 h orbit . Evidently,th e L 4 object, 198 1 S1, was photographed b y Voyager 1 las t November . (From IAU Circula r 3602} URANUS: I t i s easil y found i n Libra , nea r th e Libra-Scorpius border . See p. 87 of th e RASC Observer's Handbook for a finder chart. Its disk measures abou t 3. 9 seconds o f arc. NEPTUNE: I n opposition o n June 14, Neptune rises nea r sunset. It is in southern Ophiuchus , sporting a disk 2.5 arc second s i n diameter . oo/erving octMtie / The first official Buck Mountai n observing session for the current season was held back in April. O n Friday , Apri l 3 , severa l member s observed from the lower site without problems with mudd y entranc e roads. Two 30cm scopes, a 25cm , an d a coupl e o f 20c m scope s were present, quite a gathering of glass at Buck! The next night , observer s tried onc e agai n fo r a n evening o f viewin g bu t cloud s move d in . Meanwhile in the southern part of the province Dave Beal e an d Ala n Dye r se t u p a t Cypres s Hills Prov . Park for a weekend of astronomy at the souther n latitud e o f 49.5° ! The y wer e treated t o clea r skie s Saturday; howeve r they had also planned t o observ e an occupation by the asteroi d Aegin a o n th e Frida y night , bu t nature planne d otherwis e — it snowed. JUNE No deep-sk y observin g session s ar e planned fo r Jun e du e t o th e interferenc e of perpetual twilight , whic h i s in effect fro m May 12 to Aug . 5 or s o at our latitude . The bi g even t fo r Jun e i s th e annua l Solstice Celebratio n a t Buc k Mountain , thi s year schedule d fo r Saturday , Jun e 20 . Th e festivities get underwa y at about 9:00 pm or so, in time for th e celebrants to watch the sun not set. See page 23 for details . The Jun e Observer' s Corner, o n Monday, June 22 at 8:00pm, will featur e a talk and slide show b y Dav e Belcher, Darrel l Cross , et a l o n their recen t tri p t o Arizon a an d Ne w Mexico . There wil l b e lots o f slides and stories of their visits to th e Lowel l Observatory , Kit t Peak , the Multiple Mirro r Telescope , an d th e V.L.A. , as well a s photo s o f othe r attraction s lik e th e Grand Canyon , Monumen t Valley , etc . The y should hav e some fabulous astro-photograph y to sho w a s well . B e sure t o atten d thi s livel y meeting! The location is Rm. 445 of the Physics Bldg., U . of A . campus. At th e en d o f June , man y o f th e Centre' s members wil l b e of f t o Victori a to atten d th e General Assembly. Don't forget their observing competition. I f yo u hav e som e astrophoto graphy or results from observing projects , why not conside r an entr y int o the contest ? The prizes each year are usually quit e enticing. For more informatio n o n th e contest , contac t Observing Co-ordinato r Darrel l Cros s a t 4692931. 27 Astronomy Lectures at the Once again , ther e i s n o schedule d deep sky observin g sessio n this month . The July Observer' s Corner, Monday, July 27 at 8:00pm, will centre around a feature talk by Dr. Doug Hub e of the U . of A. Physics Dept. on the observatio n an d importanc e o f asteroi d occultations. Watchin g asteroid s pas s i n fron t of fain t stars ha s become a popular fiel d latel y for amateu r astronomers . Th e size s o f th e asteroids can be determined this way, and there have bee n report s of possibl e asteroid moons . This i s a n are a o f researc h wher e the traine d amateur can contribute usefu l results — plan to attend t o find ou t how . The meetin g wil l likel y also includ e variou s member s presenting thei r impressions an d slide s of th e Victori a G.A. Again, the O.C. is in Rm. 445, Physics Bldg. Provincial Museum Monday, August 3 Monday, August 1 0 Monday, August 1 7 Monday, August 2 4 Topics to be announced. Ail lectures are free to the public. AUGUST The first post-twilight observing session i s slated fo r th e Augus t lon g weekend , Friday , July 3 1 t o Monday , Augus t 3 , an d wha t a session i t is ! A weeken d o f campin g an d observing is being set up for Plateau Mountain . This wil l b e a join t observin g sessio n wit h members o f th e Calgary Centr e an d Medicin e Hat Clubs . Som e wil l likel y b e arriving Frida y night, bu t th e mai n observin g night s ar e Saturday, Aug. 1 and Sunday, Aug. 2 with retur n home schedule d for Monday . Thos e attendin g should b e prepared fo r a 5 or 6 hour drive from Edmonton to Plateau, and for a weekend of selfsufficient, primitiv e camping . Ther e ar e n o stores nearby , an d n o facilities of an y kin d o n top o f th e mountain . Bu t th e skie s are dark ! Don't forge t th e Manitob a Astronomica l Convention i s als o happenin g tha t weekend , under th e dar k skie s o f Ridin g Mountai n National Par k nea r Dauphin , Manitoba . I f yo u like you r campin g o r holida y weekend s a little more civilize d tha n th e condition s o n th e windswept reache s of Platea u Mtn., this i s th e event fo r you. The couple o f hundre d amateu r and professiona l astronomer s fro m acros s North Americ a tha t ar e expecte d t o atten d should mak e for a great weekend . Want to get MORE out of your TELESCOPE ? Attend the QEP' s 3-week TELESCOPE USER'S COURSE Tuesdays: June 1 6 / 2 3 / 30 To register, contact THE QUEE N ELIZABET H PLANETARIU M 455-0119 DISCOVER UNIVERSE • The RoyAl ASTRONOMiCAl Socieiy of CANAC! A EDMONTON CENTR E monthly genera l meeting s monthly observer s grou p meeting s regular grou p observin g session s use o f th e Ellersll e Observator y the annua l RASC Observers Handbook STARDUST the R A S C Journal an d Newsletter f r e e admissio n to ail Planetarium shows Prpsider.t . . . V i c e - P r e s i d e n t Dav Treasurer Me Te d Cadle n e Belche r l Rankl n RASC. EDMONTON CENTRE MEMBERSHI P APPLICATIO N FOR M Please accep t m y applicatio n fo r membershi p m the Royal Astronomical Society ol Canada, EDMONTO N CENTRE (or 198 1 Enclose d is a cheque or money order for the appropriate fee $20.00to r Adults; $12.00for Youths 1 7 and under I understand that upon receip t of m y application and fe« remittance, a membership card an d a copy of th e 198 1 Observer s Handbook wtl l be mailed t o m y address (or can b e picked u p at th e next monthl y genera l meeting) , an d tha t I will b e placed o n th e mailin g list s (or RAS C publications. Nam* Addntt. D Ne w Member D Renewa l Po*t*l Cod* Phone MAIL TO : Edmonto n Centre , RAS C c/ o Quee n Elizabet h Planetariu m C N Tower , 10t h Floor 10004 - 10 4 Avenue Edmonton , Alberta T5 J OKI. Please make all cheques payable to Edmonton Centre, R.A.S.C. Thank sI STARDUST -EDMONTON CENTRE, Royal Astronomical Society of Canada c/o Queen Elizabeth Planetarium 10th Floor, C.N. Tower Edmonton, Alberta T5J OK1 JUNE GENERAL MEETING Monday, June 8 S M . I 7& 14 15 T 2 9 16 W 3 10 17 T 4 11 18 F S 5 6 12 13 19 OBSERVER'S CORNER_2JJ| 2 3 2 4 2 5 • 27 Monday, June 22 " * SM T W T F S 1 2 3 4 5 6 7 8 91011 12 13 14 15 16 17 18 OBSERVER'S CORNER-J£20 2 1 2 2 2 3 2 4 2 5 Monday, July 27 2 6 ^ 28 29 30 3 1 AUGUST S M T W T F S • 3 4 5 6 7 8 9 10 I 1 1 2 1 3 14 15 TO: SUMMER SOLSTIC E CELEBRATIO turday, June 20 "A Galax y of One " PREMIERES at the Planetarium Friday, June 26 VICTORI A GENERAL ASSEMBLY Fri., June 2 6 - Mon., June 2 9