the newsletter of the QUEEN ELIZABET H PLANETARIUM SUMMER 198 0 and the EDMONTON CENTRE, RAS C 50$

y

SPECIAL TELESCOP E ISSU E NOW PLAYIN G

AT QUEEN

PlANETARiUM

A spectacular celestial event was witnessed by th e ancien t Sumeria n civilizatio n an d ""VELA recorded i n thei r mysteriou s cuneifor m writing. Wha t wa s it ? Th e Vela Apparition APPARITION blends archaeolog y wit h astronom y i n a search for the origins o f civilzation. 3 P M and 8 P M Daily one The night sk y i s a fascinating -realm. , nebulae, an d galaxie s ar e scattere d SUMMER'S throughout infinity . Join us for a tour of the sights o f th e summertim e sky . Rela x and NIGHT enjoy an evening at the Planetarium durin g One Summer's Night. 9PM Dail y

A special show for special people age 3 to 7. A Fantasy O f Stars chronicle s th e FANTASY adventures o f Harol d th e Her o a s h e ventures int o th e nigh t sk y t o mee t th e . A reduced admission of only o, STARS 50C for everyon e applies to thi s 3 5 minute live presentation.

For more •information , „ , please phone th re Planetariu•• , , 1:3m at 0 P M Wed . and . 455-0119 Vol. 2 5 No . 1 0 StOPCll SUMMER 198 0

Have Telescopes , Will Travel JOH N DOBSO N 1 0 People came from all over the city by bus, by car, by bicycle, and by foot to look through the telescope. Portable Astronom y DAV E BEAL E 1 8 Editor You cannot simply trust your telescope to track your camera across the sky by Alan Dye r itself. Assistant Editor Stewart Krysk o Riverside Roundu p A Pictoria l 2 2 800 people from across North America converged o n Camp Oakes fo r a Contributing Editors weekend of astronomy. Ted Cadien John Haul t Dave Holmgren Mark Leender s The Fron t Pag e Editor' s Message 2 Andrew Low e Rod McConnel l Astronomy Basic s Th e Perfect Telescop e 4 Anthony Whyte Discoveries 6 Typesetting Hardware Ne w Products 8 Lorna Mllllga n Joey Mi x At Th e Planetariu m W e Have Liftoff!..,. 2 4 Graphic Arts RASC New s 2 6 Dave Belche r Look Bac k Tim e 5 0 & 100 Ago.... 2 8 Printed by What's U p . . . 2 9

The City Of EDMONTON Parks an d COVER: Thi s month's cover photo is indicative of the theme of this issue — Recreation trends i n amateu r telescopes . I n a phot o take n a t th e recen t Riverside Telescope Maker s Conference, we se e the representative from the Questa r Corporation examinin g the ne w Dobsonia n reflector from Coulte r Optical .

STARDUST, the newsletter of the Queen Elizabeth Planetarium and the Edmonton Centre, RASC, is published 10 times a . It is available free to alt members of the Royal Astronomical Society of Canada. Edmonton Centre. Single copies are available at the Planetarium for 50C, STARDUST is also available by subscription for $3.50 per year ($4.50 after Oct. 1, 1980). Please make all cheques or money orders payable to: The Queen Elizabeth Planetarium. Write to: The Editor. STARDUST, do Queen Elizabeth Planetarium, CN Tower 10(h Floor, 10004- 104 Ave., Edmonton, Alberta T5JOK1. Unsolicited articles on any aspect of astronomy are welcome. A Special Issu e on Telescopes I hope you have enjoyed the past few issues of Stardust i n its new magazine styl e of layout . T o all those who have contributed, I owe many thanks. Keep those articles coming in! Items of any length, from short news notes and observing reports, to feature length articles are welcome. I f you hav e an ide a fo r a n article an d nee d some help in filling i t out, pleas e give me a call. I would also like to receive more in the way of photos, especially astro-photography from our readers. All the I ask is that everyone who would lik e to contribute shoul d adhere to the deadlines stated in each issue. These are firm deadlines; with the present styl e o f layou t an d printin g schedule , i t i s very difficult t o front accommodate lat e arriving material . This issu e is devoted almost entirely to one central theme — the amateur telescope. We have not bothered with covering the basics of pogc how telescopes work. I assume most of our readers are familiar with such matters. What we have endeavoured to do is present a picture of the "state-of-the-art" (an d business) of modern amateur telescopes. With items on new products, telescope manufacturing, telescope usage, the Riversid e conference, an d John Dobson' s super b article detailing hi s group's acheivements , I think yo u will be able to glean a few of the current trends in amateur astronomy . This fal l th e Quee n Elizabet h Planetariu m celebrate s it s 20t h anniversary. T o mark this auspicious occasion, the September issue will again be devoted t o a central theme— the Planetarium. We'l l take you behin d th e scene s o f sho w production , revie w th e variet y o f services the Queen Elizabeth Planetarium offers , and take a nostalgic look bac k ove r th e pas t tw o decade s of Q.E.P . history.

For exciting news about Edmonton' s new Planetariu m an d Spac e Scienc e Centre, turn to page 24.

If you hav e any old photos or press clippings pertain ing to Q.E.P. history that I might be able to use in the September issue, please give me a call as soon a s possible. Thank yo u an d good readin g ! — Alan Dyer the Planetarium Bookstore Hours: Mon.-Fri.: 8:30 - 4:30; 6:30 - 9:00 Sat., Sun. , & H o idays: 1:3 0 - 4:30; 6:30 - 9:00

CurrenPr|ce t Ne w

C 90 Tetephoto ...... $323.9 5 ...... $400.0 0 C 90 Spotting Scope ...... $389.9 5 ...... $530.0 0 C 90 Telescope ...... $695,0 0 ...... $750.0 0 C 5 Telescope ...... $999.9 5 ...... $1160.0 0 C 8 Telescope ...... $1295.0 0 ...... $1550.0 0 C 1 1 Telescope ...... ------...... $450 0 00 C 1 1 Tube Assembly ...... ------...... $310 0 00 C 1 4 Telescope ...... $8800.0 0 ...... $9670.0 0

The current prices on Ceiestron equipment will remain in effectfor all items currently in stock. As soon as this stock is depleted a new shipment will be ordered with the new prices in effect. If you are contemplating purchasing a Ceiestro n telescope, don' t wait any longer since the current stoc k will soon be sold out .

Meade

Meade has just brought ou* a beautiful 4" Schmidt-Cassegrain telescope, complete wit h eyepieces, equatoria l mount , tripod , an d a ver y sturd y aluminum carrying case. 4" Schmid t Telescope $770.0 0 o/Uonomy bo/k / the perfec t tele/cop e There i s a commo n fait h amongs t thos e owners o f short-focu s rich-fiel d scope s mus t who ar e contemplatin g th e purchas e o f a resort to Barlow lenses or eye-straining 6mm or telescope that there exists a mythical beas t -the 4mm eyepieces to d o planetary work . perfect telescope. Thi s woul d be a piec e of But fo r al l this , mos t peopl e purchasin g equipment s o well designed and manufactured their first telescope lean toward what is usually that it could be used to observe andphotograph considered t o b e a genera l purpos e f/ratio , everything i n the sky, and do i t well. something i n the order o f f/6 t o f/11. Thi s i s a Unfortunately, thi s drear n telescope does wise move, and will give the owner a telescope not exist. Let' s see why. capable o f revealin g the bes t of bot h celestial worlds, deep-sk y an d planetary . Bu t i t i s still No Genera l Purpose Objects not perfect. Ther e will always be objects at the As Davi d Lev y remarke d i n a n article i n a extreme ranges of size and brightness that will recent RASC National Newsletter, "Why (don' t not b e well observed, or no t observabl e at all . I own ) jus t on e o r tw o genera l purpos e Never fear; this is the least of your worries. instruments? Becaus e the sky ha s no general purpose objects. " Capturing I t All On Fil m This i s the start of the problem . Conside r The tas k o f findin g eve n a near-perfec t the rang e i n brightnes s o f celestia l objects , telescope i s mad e muc h mor e difficul t whe n from th e blindin g ligh t o f the sun to th e faint you wan t t o ad d photograph y t o you r glow o f distant clusters. The n consider requirements. Whil e you might be abletocome the variet y o f sizes , fro m object s spannin g close to finding a general purpose telescope for several degree s o f sk y t o target s suc h a s observing, no one telescope will ever be best for planetary e only a few seconds of arc in all types of astro-photography. Wit h patience, width. Wit h tha t i n mind , i t doe s see m our mediu m apertur e genera l purpos e f/ 6 t o remarkable that an y one telescope could even f/11 telescope can be used successfully for lots come clos e t o bein g a "genera l purpos e of astro-photography , bu t don' t expec t th e instrument." Th e secre t t o buildin g suc h a n results t o riva l the photograph s o f thos e wh o telescope is selecting the right combination of specialize i n deep-sky o r planetar y work , and aperture an d foca l length , th e tw o mos t who accordingly us e specialized equipment . important optica l characteristics , whic h More important than the optics, however, is together determin e f/ratio . the mounting . Astro-photograph y require s a A "fast " telescope , with a n f/ratio o f f/4 or solid, smooth-running equatoria l mount . Thi s f/5 {meanin g its focal length is only 4 or 5 times brings us to the final barrier in our search for the its aperture) is generally considered bestsuited perfect telescope . to lo w power , wide-fiel d deep-sk y observing . The Realitie s Of Manufacturing This i s true regardless of the aperture. A t the No complete telescope on the market today other extreme , a "slow" scop e of f/1 5 o r f/2 0 has a mountin g an d driv e syste m totall y design i s though t t o b e bes t fo r luna r an d adequate fo r astro-photography . It' s tha t planetary work , or an y observing consistentl y simple. I f yo u chec k th e system s use d b y requiring hig h magnifications . astrophotographers lik e Be n Mayer , Bra d These restrictions should never be taken as Wallis an d Rober t Provin , Le o Henz l an d th e hard and fast rules. Deep-sky work can be done like, yo u wil l fin d the m usin g custo m buil t o r with long-focu s refractors , fo r example ; i t is modified drives and mounts. Likel y as not, you simply difficul t t o acheiv e th e lo w power s will fin d Byer s gears . An d i f yo u aspir e t o necessary for large , diffuse objects. Similarly , acheive results like theirs, then you too will have to eventuall y upgrad e you r mass-produce d mount wit h som e expensive , custo m replacement. Th e Kento n Engineerin g Telescope Manufacturer s replacement driv e uni t fo r Celestron s i s a n example. But d o yo u reall y nee d tha t degre e o f precision? Fo r straigh t observing , definitel y not. No t eve n fo r mos t luna r an d planetar y photography, an d likel y no t fo r "piggyback " deep-sky shooting . Th e drives and mounts on our Celestrons , Meades , Edmunds , Dynamaxes, and yes, even Questars, are not the examples o f mechanica l perfectio n w e migh t like them to be for a very good reason. Mos t of us don' t nee d tha t precisio n an d therefor e shouldn't be forced to pay for it, Manufacturers have t o kee p thei r price s dow n t o b e competitive, and that means a less-than-perfect telescope. Surprisingly enough , th e economic s o f large volume manufacturing has not resulted in vastly inferio r optics . Th e optica l qualit y o f a modern Celestron or Meade remains very good, even though Celestron , for example , turns out some 50,000 C-8's pe r year. The deficiencie s o f mos t commerciall y made telescopes ar e usually mechanical ones. Sometimes yo u can chalk the m u p to just bad design. Bu t mor e ofte n tha n not , th e mechanical shortcoming s yo u fin d coul d no t have bee n avoide d withou t undul y increasin g the cost o f the telescope. So What's Lef t ? It seems frustrating that th e $50 0 to $2000 we commonly spend these days for a telescope will no t ge t u s a n opticall y an d mechanicall y perfect telescope . Bu t suc h i s the way o f th e world. Eve n so , today' s commerciall y mad e Newtonians, Maksutovs , an d Schmidt - Casssgrsin tolescopes still represent excellen t value fo r th s money . Th e well-know n SchmidtCassegrain models , i n particular , incorporate probabl y th e bes t compromises of quality vs . economy , apertur e vs . portabilit y and versatility vs. simplicity . If yo u ar e stil l no t satisfie d wit h compromises, then you can invest i n any of the super-optics an d super-mount s becomin g increasingly availabl e from manufacturer s like R.E Brandt, Byers , or Astro-Works. A s always, you ge t what you pa y for. ' - - Alan Dyer di/couci ic/... and othe r neuu /

RINGS AROUND THE EART H ? biological change s associate d with a climatic A syste m o f Saturn-lik e ring s ma y hav e upheavel coincid e quit e accuratel y wit h a surrounded th e earth 34 million years ago. This massive fall of tektites from outer space . While is th e conclusio n o f Dr . Joh n A . O'Keefe , a the precise origin o f these glass meteorites has scientist a t the Goddard Space Flight Centre in not bee n established, a common theory i s that Greenbelt, Maryland . Durin g thei r lifetim e of they cam e from a giant meteo r impac t o n the several millio n years , the ring s (o r rathe r the rnoon. shadow o f th e ring s o n th e earth' s surface) Some of the materia l thrown off the moon would have caused dramatic climatic changes. by the force of the impac t mad e i t to earth as A sudden climatic change 34 million years ago tektite meteorites . A portio n o f th e tektit e has been known to geologists for many years as barrage may have missed the earth and formed the "termina l Eocen e event, " bu t unti l now , a ring of particles orbiting our planet. The ring there has never been an acceptable explanation would hav e blocked sunlight, with the effect in for the event. the northern hemisphere at its worst near winter Where did the rings come from? Th e basis solstice, causin g a declin e i n averag e winter of O'Keefe' s belie f lie s i n th e fac t tha t th e temperatures.

JUPITER'S 15th photograph tha t showe d both th e shadow and Last yea r a 14t h satellit e o f Jupite r wa s its source - - the ne w satellite, no w designated discovered on one of the Voyager 2 spacecraft's 1979 J2. I t Jupiter once every 16h16mata photos b y researcher s who originally though t distance o f slightl y mor e tha n 151,00 0 the poin t o f ligh t wa s a . No w anothe r kilometers from the cloud tops. Thi s places i t worker, Stephe n Synnot t o f JPL , wh o wa s between the orbits of Amalthea and lo. Synnott looking fo r th e sam e objec t i n Voyage r 1 estimates its diameter as 80 kilometers, at feast photographs, ha s instea d discovere d ye t along it s shortest axis; the new satellite may be another satellite , Jupiter' s 15th . H e report s elongated lik e Amalthe a and Synnott i s trying having detecte d wha t looke d lik e a shado w to se e if it s long axis can b e glimpsed i n other against Jupiter' s dis k whic h change d positio n Voyager photos. Th e new satellite is "about as in successiv e photos. Afte r several weeks of dark a s Amalthe a an d ma y b e o f simila r search Synnot t finall y locate d a singl e composition."

SATURN: MOONS AND MORE not been sighted this year. Itisnowthoughtthat MOONS Janus doe s no t exist . However, a n 11t h moon A rash of recent investigations has revealed discovered b y astronomer s Fountai n an d an abundance of ne w moon s o f Saturn . They Larson in 1978 on plates taken in 1966, has been have als o relegate d a n ol d moo n t o th e confirmed with new earth-based observations. nonexistent category . This object was also sighted by the Pioneer Janus, the 10th moon of Saturn, discovered 11 spacecraft las t September . A s i t fle w pas t in 196 6 when th e ring s were last edge-on, ha s Saturn, Pionee r 1 1 nearl y collide d wit h thi s moon, missin g i t by that much! A second ne w thought t o b e multipl e sighting s o f th e sam e satellite may have also been indirectly observe d object or of one or more of the new Pioneer 1 1 by Pionee r 1 1 but remain s unconfirmed . objects. Bu t even taking multiple sightings into During the first half of 1980 with Saturn well account, there is still a confusing array of some situated fo r observation s fro m eart h an d it s one doze n ne w bu t unconfirme d moons . B y rings edge-on , astronomer s i n France and the autumn, mos t o f thes e will likel y b e narrowed U.S. hav e announced sighting s of n o less than down to just a few confirmed objects, but ones 24 previousl y unknow n moons . Som e ar e with perhap s unusual orbits .

-SO'

DISCOVERING VENU S Based on extensive radar data returned by mountain tower s 11,800 m (35,30 0 ft. ) abov e NASA's Pionee r Venu s spacecraft , scientist s "sea level," taken to be the mean surface level of have for the first time mappe d nearly the entire the planet . cloud-covered planet . Pionee r Venus has now 60% o f Venus ' surface i s a relativel y flat , mapped 93% of the surface, compared to the 1 % rolling plain, punctuate d b y what appears to be mapped previousl y b y ground-based radar . large, shallow craters . Among the features identified are two huge The lowest point on the planet is a rift valley continent-like features . Th e larges t o f thes e just eas t o f Aphrodite . I t i s roughl y th e sam e highland regions , name d Terr a Aphrodite , i s depth as Vallis Marineris, the grea t canyon o n half a s larg e a s Africa. The smalle r highlan d Mars. region, Terr a Ishtar , i s th e siz e o f th e Despite th e variet y o f surfac e features , continental U.S. Two other notable features are NASA scientist s conclude tha t Venus' crust is Beta Regio , site of wha t seem to b e two gian t so thick that it has choked off the sort of crustal shield-type volcanoes , an d Alph a Regio , a movement o r "plat e tectonics" w e experience region of roug h terrain. on earth. Venus' crust is apparently composed The highest point found on Venus is on the of on e hug e tectoni c plate , compare d wit h east end of Ishtar. Named Maxwell Monies, this earth's six majo r and several minor ones . neuu product / THE LONG-AWAITE D CELESTRO N 1 1 At th e recen t Riverside Telescope Makers Conference, Celestron unveiled the proto-typ e unit of their new C-11 telescope. The design is similar t o th e C- 8 and C-1 4 instruments , wit h characteristics of both. The C-11 tube assembly will separate from the fork arms for transport as with the C-14. I t will be shipped in two steamer trunks. Optica l configuratio n i s a n f/1 0 Schmidt-Cassegrain and the drive is said to be a worm-and-wheel type. Unlike the C-14, the C11 does no t appea r t o b e equipped wit h electri c slow-motion control s o n eithe r o f th e axes . Highly portabl e fo r it s aperture , th e C-1 1 i s destined to be a very popular model. Availability is expected by year's end, with the base price in The proto-type of Canada starting a t $4500.0 0 the new C-11

NEW OPTICAL SYSTEM FRO M R.E.BRAND T R.E.Brandt Lensworks , well-known for his are Pyre x with Schot t Zerodu r availabl e as a refractor objectives , ha s announce d th e option. Reflectiv e surface s hav e enhance d availability o f a 12-inch Hybri d Maksuto v tub e aluminum coating s whil e th e correcto r ha s a assembly. Featurin g an f/4.4 Newtonian focus broad-band multi-coatin g fo r hig h and a n f/2 0 Cassegrai n focus , thi s syste m transmission. The total weight of the system is boasts totall y coma-fre e images . Th e field - 70 Ibs . Price s ar e $770 0 U.S . (wit h Pyre x ofview a t th e Newtonia n focu s i s 1.4° . Th e mirrors); $9700 (with Zerodur mirrors). Delivery central obstruction in the Cassegrain mode is a is 12 months. Fo r more information, contact: L. low 22 % b y diamete r o r 5 % b y area . Th e Henzl and Associates, 215 West Leroux Street, corrector len s i s BK-7 Crown glass; the mirrors Prescott, Arizona, USA 86301.

NEW SCHMIDT-CASSEGRAIN FROM MEADE Dubbed the Mead e System 1000, this new 4-inch (100mm ) apertur e f/1 0 syste m i s available in 3 configurations: A telephoto lens, a spotting scope , an d a n equatoriall y mounte d telescope. The telephoto lens features a helical focussing camera mount. The other two models have a rear focus knob that move s the primary mirror bac k and forth. The eyepiece size is the Japanese standar d .965" . A ful l lin e o f accessories i s available, and al l adapter s an d filters ar e compatibl e wit h Celestro n equipment. A n electri c moto r fo r th e The new Meado 4" Schmidt-Cassegrain Germanstyle equatoria l moun t i s available as an option. BYERS PRODUCTS AVAILABL E AGAIN Model 4, an equatorial tracking platform for fork Edward R . Byer s an d Co . i s bac k i n th e mounted Celestro n 1 4 (under $1700 ) astronomy busines s agai n afte r a n absenc e Model 5, a German equatorial mountin g fo r 4" - fulfilling contract s wit h NAS A an d th e U.S . 8" scopes includin g C-8 (unde r $500 ) Government. Lon g know n fo r thei r precisio n Model 6, an equatorial tracking platform for fork mounts an d drives, Byers has announced a new mounted Questa r 3.5, Quantum 4, or Celestro n line of products. Of particular interst to amateur 5 (unde r $350) . astronomers are their new portable mountings . All thes e mount s featur e a n accurat e 6 model s are being introduced : sidereal trackin g syste m wit h lever-operate d Model 1, a German equatorial mounting fo r 8" - worm gears , built-i n timers , slip-rin g typ e 12 1/2" telescope s (under $1000 ) setting circles , and precisio n latitud e and Model 2 , A German mounting for 1 2 1/2" - 16" azimuth adjustments . Al l price s liste d are the scopes (unde r $2000) projected U.S . prices . Thes e product s shoul d Model 3, an equatorial tracking platform for fork be available this summer. For more information, mounted SchmidtCassegrain s and Maksutovs contact: Edward R . Byers Co., 29685 Cuthbert up to 10 " i n aperture (unde r $600 ) Road, Malibu, California, USA QOPfifi

GALAXY FILTER S FROM LUMICO N Similar i n constructio n t o th e popula r nebular filters , th e ne w galax y filter s fro m Lumicon hav e increase d transmission i n th e blue en d o f th e spectru m an d near-tota l rejection i n th e yellow-gree n portion . Thi s blocks som e emissio n line s fro m mercu ryvapour an d sodium-vapou r streetlamps an d mos t skyglo w fro m natura l sources. Th e blu e sensitivit y i s suitabl e fo r observations o f and clusters, but does let throug h som e o f th e majo r line s fro m mercury-vapour lights . Th e ne w filter s ar e therefore not as effectiveasthefamiliar nebular not b e observe d throug h th e re d an d gree n filters fo r ligh t pollutio n rejection , bu t o n the sensitive nebula r filters . Fo r more information, other han d ca n b e use d fo r enhance d contact: Dr. Jack B. Marling, 891 Laguna Street, observations o f galaxie s and clusters that can Livermore, California, USA 94550.

A DOBSONIAN REFLECTOR FROM COULTER OPTICA L Now available from Coulter Optic s i s their "Odyssey 1, " a 13.1" f/4.5 Newtonian telescop e on a classic Dobsonian alt-azimuth mount. The mirror i s 1-inc h thic k Cornin g Pyrex , held i n place by a wide strap along the bottom edge of the mirror and 9-point flotation cell. The mount is of sturd y plywoo d constructio n wit h Teffon bearing surfaces . The telescope comes with a 25mm eyepiec e an d feature s a blue Zolatone finish. Th e U.S . pric e i s $395.00 plus a $75.00 crating charge . Th e approximat e shippin g The Odyssey 1 weight i s 15 0 Ibs . Fo r mor e information , from contact: Coulter Optical Co., P.O.Box K , Coulter Idyllwild, California, USA 92349. Have Telescopes, Will Travel

*|] Reprinted fro m th e April, 1980 Issu e of "Sky and Telescope" \dth permission of the author and of Sky Publishing. £ Photo CredHs : p 10/1 1 an d p 14: Dennis DtClcco ; p 15 : San Francisco Sidewalk Astronomers Photos use d by permission. &£!

by John Dobson San Francisco Sidewalk Astronomers

A dozen or so years ago, before the road to the to p o f Moun t Tamalpai s nort h o f Sa n Francisco wa s closed a t night , a friend with a station wago n ha d taken me up there with on e of my 12-inch telescopes. Some 200 people had spent th e evenin g crowdin g th e lin e t o th e eyepiece, again and again, to get a good look at the quarter moon , Satur n an d other objects. When i t came time to leave , I wheeled the telescope to the station wagon and tipped th e front en d dow n til l i t reste d o n th e tailgate . Lifting th e back end of the telescope, I pushe d the 7-1/2-foot tub e int o the wagon and placed the altazimuth rocker i n besid e it . I t was then that I becam e awar e o f bein g watched , an d I heard someon e mutte r unde r hi s breath , "H e can pu t down tha t 12-inche r faste r than I can put down m y 6." That was Herman Fast of the San Francisco Amateur Astronomers. Althoug h w e had heard of eac h othe r throug h a mutua l friend , year s before, we had never met. W e fell to talking and, when he saw that the telescope was made out of junk an d hear d tha t I ha d groun d th e mirro r myself from porthole glass , he asked me if I had heard of the Buddhis t mon k who was grinding glass underwate r to escape detection. For a moment I wondered, "Why should a Buddhist monk... ? "-the n suddenl y I blurte d out, "Yo u mus t mea n me , an d yo u mus t b e Herman Fast." I wasn't exactly a Buddhist, I am a Vedantln , bu t I ha d spen t 2 3 year s i n a monastery. U p i n Sacramento , I had groun d telescope mirror s fro m th e bottom s o f gallo n jugs, and sometimes I had ground them in a pail of water to muffle the sound — grinding mirrors was hardly on our curriculu m Some o f thos e earl y mirror s wer e ground so Shorty could vacuum it, and with a little help with san d I had screened myself, and polished from my friends, i t took m e nearly two years to with rouge that I made from ferrous sulfate and accumulate $4 5 t o hav e m y firs t 18-inche r oxalic aci d whic h w e kep t i n th e garde n aluminized s o tha t I coul d "float " i t o n the department. I n the monaster y there wa s little neighborhood. I n those days I would wheel my opportunity to mix with othertelescope makers, telescope down the street till some child asked and I had already figured 15 12-inchersandtwo me what it was. "It' s a telescope," I would reply, 18's (al l porthol e glass ) befor e I ever ha d th e "Want to borrow it? " "Sure! " chance t o loo k throug h anyon e else' s Then he would ask his mother. I f she knew telescope. me i t wa s okay . I f not , sh e migh t hav e And when finally I had the chance to do so, I misgivings and we'd go from door to door til I we threw th e eyepiec e out o f focu s on Veg a an d found another mothe r willing t o keep a 12-inch told my host abruptly that he had a good mirror, telescope i n her garage for a month. The n I'd slightly overcorrected , and warped by the cell. sneak out of the monastery at night, usuall y on He was furious . a waxin g moon , an d al l th e kid s i n th e "How can you know that?" he said angrily. neighborhood woul d hav e a chanc e t o loo k "I worke d fo r month s i n tha t dar k basement . through the telescope. How can you know that?" (I n those days, I had My firs t 18-incher , no w calle d Th e Littl e no ide a o f excellenc e standards for a mirro r One, was a bit larg e for wheeling, so it lived in curve, but was accustomed to "reading" mirrors one house for months on end. Lik e Paul Revere, at the eyepiece. I tested my mirrors, as I still do, I'd ride through the streets in the evening on an at the focus , by comparing the distribution of old bicycle , inviting al l the peopl e I met to go light i n th e enlarge d disk s o n eithe r sid e o f and look through th e telescope at that address. focus, with the telescope trained on a star or on Needless to say, my stay in the monastery was the spo t o f reflecte d sunlight on a power pol e soon terminated o n the grounds that I was too insulator. I jus t worke d til l I coul d se e the often "AWOL, " bu t b y tha t tim e ther e wer e surface details on the galvanized roofing nails 12inchers all through th e neighborhood . atop a power pole , about tw o block s away.) Our tube s wer e cardboar d core s o f discarded hose reels 22 inches long. W e made mirrors wit h 66 - or 88-inc h foca l length s and I'd sneak out of the monastery called them three-barrel orfour-barrel 12's.The at night and all the Idd s In the telescope I took to Mount Tamalpais years later was on e of those four-barrel 12's . neighborhood would hav e a Those telescopes were made of junk, with chance to look through th e cardboard tube s an d woode n rocker s — window cutout s fro m schoolhous e door s o r telescope. scraps from a debris box. An d they moved on rusty wheels from childrens1 discarded wagons. Later, whe n I invite d m y hos t t o loo k Our diagona l flat s wer e scrounge d fro m through m y 18-inche r o n a very still night , we military surplus , an d wer e glued t o piece s of had clear , blac k sk y betwee n bot h pair s i n wooden handrail with scraps of leather cut from Epsilon Lyrae , an d I showe d hi m th e Rin g the tongues o f old shoes . Eve n the struts that nebula an d the Hercule s globula r cluster M13 . held the diagonals i n the tubes were unusual -- He said he' d neve r seen these objects s o well. old ceda r shingle s blow n fro m th e side s o f Then h e told me , "You wer e right. I had my buildings i n a storm. mirror tie d dow n to si x point s i n it s cell. I'v e The San Francisco Sidewalk Astronomers' released i t no w and it works better." 24-incher, Delphinium , wa s also mad e largely For a monasti c withou t asset s or income, out of junk. Bu t it was built at a later time, and making telescopes surreptitiously i s not easy . by then the scene ha d changed. I n 1967 I had Selling Gree n Stamp s and Blu e Chi p Stamp s left th e monaster y an d hitchhike d t o Sa n for cash , an d cleanin g th e coin s ou t o f th e Francisco, where I lived in the house of afriend. Arden Hilfs swimming pool in the early morning It was there that I first started teaching classes 12 at th e Jewis h Communit y Cente r an d bought, with borrowe d money , som e fou r ton s o f porthole glass. I had m y old four-barrel 1 2 with m e at that time an d use d t o se t i t u p o n th e sidewal k at Jackson an d Broderic k Street s o n every clear night, where it caused a real stir. Peopl e came by bus, b y car, by bicycle, and b y foot to look through the telescope. They came from all over the cit y an d the y brough t thei r friend s fro m across the Bay . We ca n see four star s in the Ring nebula In Lyra , globular clusters In the Andromeda Galaxy, and the shape s of galaxies In the Corona Borealls cluster, The corne r wa s thronge d lik e a n ol d marketplace. Bo y met girl there, and the hippi e movement wa s just i n flower. I n those days it was sai d tha t th e telescop e a t Jackso n an d Broderick ha d become the talk o f the cocktai l parties alon g "millionaires ' row. " A s for me, I The traditional Dobsonia n uses a thin mirror slun g In was destitut e a s ever , livin g o n weed s an d a stra p In the fold-down tailgate . wildflowers for lunch . It was out of this turmoil that the Sidewalk Astronomers wer e born . W e met on th e first the carborundum , squeegeein g th e exces s Saturday nigh t after the first-quarter moo n and water fro m th e fac e o f th e too l wit h m y set up the telescopes on the corner. Eve n when increasingly sor e palms . Roug h grindin g is a it raine d w e me t ou t there , havin g n o othe r cave-man's job — eat well, sleep well, and work place. Afte r a year or so Brian Rhode s heard of like hell ! I n 1 9 hours w e ha d i t groun d an d me through a friend and asked my help to figure polished. An d i n thre e month s w e ha d i t his 8-incher , whic h w e di d o n th e to p o f finished - - freeway portable - - a t a total cost of Tamalpais above the summer fog. Tha t day he $300. took hom e glas s for a 16, which soo n becam e A fe w year s later , a t the Lawrenc e Hal l o f our workhors e telescope . Brian' s van became Science in Berkeley one night, we were looking our wheels , an d Brian himsel f th e backbone of at Come t Kohoute k throug h th e 24-incher . A the Sidewalk Astronomers . young ma n asked me how long it had taken us In May of 1970 , Brian sawthe 24-inch blank to grind the mirror. Whe n I told him he left, and in my room at 1600 Baker Street and asked if we an hour or so later he returned to say that he had couldn't begi n to work on it. We started at once. asked hi s scienc e teache r abou t it , wh o sai d Brian i s a mechanic , and a t tha t tim e ha d a that w e couldn't eve n have prepared the pitch fulltime job. W e worked on the 24 late at night in lap i n 1 9 hours. stolen hours after work and sometimes on the Little did he know how we pour pitch laps -a weekends. I t too k u s 12-1/ 2 hour s t o five minut e jo b a t most . Afte r smearin g th e roughgrind th e mirror. Fo r the most part Brian mirror fac e with wate r and ceriu m oxide , an d pushed th e glass and I managed the hose and warming th e too l an d smearin g the face with 13 turpentine, w e slowly pou r the soft pitc h ont o The thinness of the mirror i n some ways is the tool face and watch it spread till it nears the an advantage . Durin g grindin g and polishing edge. Then , quickly, we press the mirror glass there was less glass to accelerate fore and aft, facedown on the pitch, swirl it, and slide i t off. and we don't nee d a forklift to put the mirror in Quickly again, we groove the pitch with the wet its cell. crossbar of a wooden clothes hanger and press But th e thinnes s doe s introduc e again with the mirror . complications i n th e suppor t mechanism . The 24-inch mirror is, of course, a porthole, During the initial star-testing, Brian and I had it only 1 inch thick at the edge and 3/4 inch at the on a nine-point flotatio n system . Bu t the star center. Probabl y al l th e ol d authoritie s o n disks o n bot h side s o f focus looked like littl e mirror makin g woul d hav e forbidde n it s benzine rings ! W e the n replace d th e nin e existence. Bu t four professiona l astronomers leather pad s o n th e plywoo d triangle s wit h have tol d u s tha t they'v e neve r ha d a bette r round-head screw s that fi t i n sockets on nin e show throug h an y telescop e a t an y time . hardwood sticks , th e latte r havin g leathe r Through i t w e ca n se e four star s i n th e Rin g pieces a t eac h end . Ove r thi s 18-poin t nebula in Lyra--two in the faint green inner part suspension, w e place d a thi n cardboar d and two mor e in the surrounding nebulosity . "bib, "glued down to two of the leather pads. A We ca n se e th e globula r cluster s o f th e circumferential stra p rest s on th e bi b an d the Andromeda galaxy and some of its luminous O- mirror slides down th e bib and hangs in place. and B - type stars. Th e spira l arms of M7 4 i n Pisces ar e seen, and w e can eve n distinguis h the shape s o f th e galaxie s i n th e Coron a Borealis cluster at a distance of about a billio n light-years. The entir e mechanis m i s buil t int o th e telescope "tailgate, " whic h i s hinge d t o th e instrument's boxlike lower end for easy loading of th e mirror . Whe n th e telescop e i s operational, the tailgate is screwed up tight to the en d o f th e bo x wit h fou r 3-1/2-inc h stainless-steel screws. The bo x o f Delphiniu m i s mad e ou t o f damaged plywood , on e shee t o f 1-1/8 - inchthick floorin g plywoo d an d on e shee t o f 3/4inch. Th e rocker and the ground board were made fro m discarde d doors . Bria n an d I decided to order 4-foo t and 8-foot sections o f 30-inch cardboard tubing. Whe n larrived at the local supplie r o f contractors ' tubular form s I found Bria n alread y there with pieces of these lengths standing on the loading dock. W e each assumed the other ha d placed the order earlier that day , bu t they proved to b e dunnage from another customer's order. I turned to Brian with the remark, "Something i n this universe wants that 24." Another day I found a crew dismantling the power pole s on Pin e Street, only a block from my house. Seein g that stout crossbar lying on the sidewal k wit h thos e grea t insulator s an d John Dobso n (kneeling ) Install s th e 24 " mirro r I n other hardware , I said to a crewman, "You'r e Delphinium. just goin g t o thro w thos e things away , aren't 14 The Sidewal k Astronomer s often set up their collection of telescopes at the Gran d Canyon. A t lef t is The Littl e On e (18") , an d behin d Delphiniu m (24") I s The Phoenlx(22") . At the righ t i s The Grea t Spac e Moth (16" ) an d Stellatrope (th e author' s ol d four-barrel 12") . you?" Th e beam was 4-1/2 b y 6-1/2-inch first - We firs t star-teste d th e 24-inc h mirro r o n class, straight-grai n lumber . I t supplie d th e Mount Tamalpai s durin g a n eclips e o f th e structural member s fo r th e telescop e groun d moon. We' d had it temporarily silvere d so that board as well as those of the trailer to which the we coul d ge t t o th e Wester n Amateu r telescope is bolted fo r freeway travel. Astronomers conferenc e in Sacramento a few Ata mountai n observing site, the telescope days later. Tha t was its debut. Stil l silvered, we is lifted off the trailer and set on the ground o n took i t t o Deat h Valle y a t Christmastim e its ow n thre e feet . Th e tub e slide s int o th e through a blizzar d whic h strande d 7,00 0 upper en d o f th e bo x tha t house s the mirror . motorists i n the passes. I t was there that I first The weight of the box and tube is carried to the slept i n the tube . rocker through four Teflon bearing pad s on the We staye d through si x days and night s o f vertical cradl e boards . Th e rocke r swivels in wind and rain, but on the last night, within plain azimuth o n thre e mor e Teflo n pads , an d th e sight of the mercury-vapo r light s of a gasoline weight i s born e t o th e groun d throug h thre e station, w e could se e the Horsehead nebul a i n fixed feet under the ground board . A n observer Orion withou t th e slightes t nee d fo r averte d can mov e the telescope easily from the top of vision. Bria n wasn't with me on that trip, but in our 12-foo t ladder . W e us e Teflo n t o avoi d the hope of refiguring the mirror before getting backlash i n th e bearing s an d ye t provid e it aluminize d i n Januar y h e ha d aske d m e t o enough frictio n t o kee p th e telescop e from reread its figure before leaving Death Valley. I moving undul y i n the wind. read it on our last morning at Furnace Creek on 15 The Centre's Dobsonian Projec t Members o f th e Edmonto n Centr e ar e currentl y involve d i n a project t o acquir e a larg e apertur e Dobsonian reflecto r fo r the Centre. The initial idea was to purchase an 18" porthole glas s blank from Joh n Dobson himself i n San Francisco. Arrangements were made to this end, but the announcement by Coulter Optical of the availability of a finished 17.5 " f/4. 5 mirro r (with secondary) mad e grinding our own mirror a needless chore. The cost of the mirror i s $595.00 in U.S. funds, plus shipping. I f the Centre purchases this item for us e by all members, we should be able to import the mirror duty and tax free. If this is the case, the final cost to u s would b e about $750.0 0 Canadian . The proposal before the membership i s that the Centre purchase a Coulter 17.5 " mirror , and build a standard Dobsonian moun t t o accommodate it. The cost of the materials for the mount shoul d b e about $200.00. Th e finished telescop e woul d eventuall y b e store d a t Buc k Mountai n eithe r i n a separate shed/observatory o r i n th e propose d warm-u p hu t itself . Till thes e are completed, th e scope coul d b e housed a t Ellersli e an d transported to a darker site when necessary. A standard station wago n or van is sufficient to transport the scope. Those presen t a t th e Jun e 2 3 Observer' s Corne r meeting , hel d t o discus s th e matter , wer e ver y enthusiastic about acquiring a Dobsonian and many indicated that they were prepared to donate funds to the cause. Mos t were prepared to donate $100.00 , thoug h a donation o f any amount would be very much appreciated. This, then, is where the project now stands. Donations are being collected and when we are assured of sufficient funds, the mirror will be ordered. Jim Jacobson of Coulter Optical has informed us that delivery on the 17.5 " optic s i s about 6-8 week s (bu t a longe r dela y shouldn' t surpris e us!) . Wor k coul d begi n immediately on the mount and tube assembly. This work could be carried out in parallel with the occasional weekend work partie s at Buck Mtn. It seems reasonable to expect that the telescope could b e finished by next spring, i n time to view those fantastic galaxies, spiral arms and all! If you wish to donate to this cause, please make all cheques payable to: The Edmonton C«ntr«, R.A.S.C. All donations are tax deductible and receipts will b e issued.

SEND TO: Me l Rankln, Treasurer , Edm . Centre; the glint of sunlight i n a raven's eye . eyepiece field at that magnification . When th e 24-inc h mirro r wa s finall y The following night, in the Bristlecone Pine aluminized we took it up to 8,000 feet on Mount Forest one rang e east of the Sierras , we set up Rose to entertain the girls from a summer camp the 24 on White Mountain, again at 10,000 feet. at Lak e Tahoe . Ther e w e foun d tha t it s In spit e o f a quarter moon , w e sa w the spira l performance outstrippe d ou r wildes t arms o f M8 1 i n Urs a Majo r a t it s lowes t poin t imaginations. Th e following nigh t w e were at above th e horizon. Nearl y overhead, when the Sherwin's Summit . A n astronome r happene d moon wa s sinking , w e sa w th e cluste r o f by an d remarke d tha t th e vie w o f th e Trifi d galaxies i n Hercule s — a dozen at a time in th e nebula through the 24 was more exciting than eyepiece field — and the surrounding darknes s his professionl slide. looked lumpy . Th e fiel d i s locate d abou t 5 ° We nex t wen t u p a glacia l valle y t o west-southwest o f Gamm a Hercults . Mosquito Flat , a t ove r 10,00 0 fee t i n the Joh n Later, at the suggestio n of the Fores t Muir Wildernes s area , o n th e highes t pave d Service, we took the telescope to the Alpha and road in the Sierras . Fro m there , the Pleiade s Omega Rest Area at only 5,000 feet on the west were wall-to-wall nebulosity, and we could see slope of the Sierras, to entertain the students of the detailed structure of M33 . The Andromeda a school in Nevada. Ther e with the help of Lee galaxy wa s seve n eyepiece-field s lon g a t 150 McDonald, we first saw the cluster of galaxies in power, and it took a great deal of time to scan it. Corona Borealis , mor e tha n thre e time s a s Even its satellite galaxy, NGC 205, spanned the distant as the group i n Hercules. Th e light we 16 saw the n ha d lef t thos e galaxie s mor e tha n a bare eyes . Th e intricat e detail s i n th e clou d billion years before, during the formation of the bands an d th e sharp , roun d shadow s o f th e Late Precambrai n rock s exposed at the bottom moons cause most viewers to gasp. On another of the Gran d Canyo n gorge, over which seven occasion w e could see a big brown patch within oceans hav e come an d gone. the pola r ca p of Mar s that looke d a s though a Since those early trips, the 24 has traveled great warm rock ha d melted the snow for mile s over 30,000 miles in public service. I t has been around, four times to the Grand Canyon, many times to When th e seein g i s troublesome , a s i t Death Valley , man y time s t o Glacie r Poin t i n usually i s belo w 7,00 0 feet , w e ofte n us e Yosemite (wher e ther e shoul d b e a publi c offcenter elliptica l stop s for viewing luna r an d observatory with a t least a dozen 18-inchers) . planetary detail. O n the 24 this gives us a 10-by It ha s recentl y bee n joine d b y Gerar d 15-inch unobstructe d ova l aperture, whic h not Pardeilhan's 22-incher. Fo r this mirror' s fina l only improve s th e imag e bu t increase s th e figuring, we carried the 13-foot tube upstairs to depth o f focus by increasing the focal ratio . Gerard's roo m a t 160 0 Bake r Street, where we In the summer of 1978, on tourtothe Grand had replace d th e windo w glas s wit h paralle l Canyon, we took the 24, the 22, The Little One, plate so that we could read the mirror through a and 16 , some smaller stuff, and several of ou r closed window , usin g a glint o f sunligh t o n a sun telescopes in which the sky end of the tube power-pole insulato r abou t hal f a block away. is a full-apertur e cove r glass , se t a t 45 ° an d partially aluminize d on th e inside . (Th e glass acts bot h a s a sola r filte r an d Newtonia n We've mad e tons of glass into diagonal, and it is completely fail-safe because telescopes so that millions of no light can pas s to the eye if the glass should ever b e shattered or detached . people could see. In a fittle ove r two weeks , we entertaine d some 20,00 0 people. Man y of them told us that At on e stage his mirror had a high center, our preliminar y tal k o n th e natur e o f space , and we tried to correct it with tension. We glued time, electricity, and gravity, followed by a slide a bloc k o f woo d t o th e cente r o f the mirror' s show, mad e th e late r look s throug h th e bi g back, from which we ran a string through a hole telescopes al l th e mor e worthwhile. Man y of in th e telescop e tailgate . W e move d th e them remarked that finding us in a national park flotation triangle s ou t farthe r fro m the center was the highlight o f their summer trip. and hun g abou t 3 0 pound s o f lea d o n th e Our trip s hav e bee n possibl e largel y central string . Tha t correcte d th e curv e b y because our telescopes are inexpensively built. nearly 1/ 8 wave, but this was not sufficient, so When I first bought the four tons of portholes, I we refigure d th e mirro r an d restore d th e was afrai d tha t i n orde r t o pa y bac k th e flotation system to it s original configuration. borrowed mone y I might hav e to sell many of For th e mos t par t thes e bi g telescope s them as garden stepping stones. I t never cam e operate above 7,000 feet. Th e South Rim of the to that , an d b y no w that glass i s long gon e to Grand Canyon, Wolverton at Sequoia National telescope makers. Park, an d Glacie r Poin t i n Yosemit e ar e al l Since th e earl y monaster y day s I hav e above this elevation. Wha t can be seen through helped thousands of people figure their mirrors. these larg e aperture s depend s largel y o n th e We've made tons of glass into telescopes so that seeing condition s - - muc h mor e s o than wit h millions o f people coul d see. Th e professional the smalle r telescope s wher e th e destructiv e observatories ca n neve r handl e th e publi c influence o f turbulenc e i s muc h les s desire to view astronomical objects . W e need pronounced. O n a very still night a t the Grand public observatorie s i n the stat e parks an d i n Canyon year s ago , Jupiter throug h th e 2 4 the nationa l park s and monuments. Tryin g t o looked a great deal more like the flyby pictures serve this need has been the pleasant task of the than lik e an y ground-base d pictur e w e hav e Sidewalk Astronomers, but a great deal remains ever seen . I n this instrumen t th e giant plane t to be done. Million s o f eyes are waiting to see. appears as bright a s the full moo n doe s to the Millions o f peopl e are eager to understand . 17 Portable

by Dave Beale Edmonton Centre RASC

Most amateur astronomers do not have access to the luxury of a permanent observatory, an d therefore must us e a portabl e telescope. This creates a special set of problem s for observers . Here are a few techniques to help you ge t the most out of your telescope during a night's observing.

Author Dav e Beal e and hi s ow n se t up for portabl e astronomy. Dave' s equipment feature s a C-B with a Kencor driv e an d driv e corrector , a custo m mad e lightweight tripo d wit h levellin g legs , an d a convenient cas e for carrying an d storing eyepieces, adapters, filters, cords, and the scope Itself . 18 FINDING A SITE As a n ai d t o alignin g you r telescope , Except fo r Edmonto n Centr e member s purchase a small bubble leve l and glue it to your (who have both a Near and a Dark Site), the first tripod. A Craftsman circular type is only a few question i s always, "Where shall I go to setup?" dollars and is very sensitive. As you may know, For visual observing only, a very dark site is not Polaris i s no t exactl y o n th e Nort h Celestia l necessary, as long as there are no bright lights Pole, but about a degree off. An excellent pola r directly visible . Mor e experience d observer s alignment char t showin g th e fiel d o f star s can find darker sites to their advantage, but the around Polari s and the locatio n of the NC P is beginner i s often confused by all the stars! contained i n the "Messier " se t o f AstroCards, The sit e should hav e some sort o f natura l popular amon g Centre members . protection fro m th e prevailin g winds , goo d After roug h alignmen t an d levellin g wit h access, and not involve trespassing so as not to your scop e set at 90° , you shoul d aggravate farmer s and viscious yar d dogs . I t see the stars in Figure 1 in your finder scope. I should als o b e relatively close to hom e so the recommend first centering Polari s in the cross- observer can use it fairly often. A distance of 20 hairs of the finder. The telescope ma y then be to 40km from the city is a good compromise of rotated 180 ° i n righ t ascensio n t o b e certai n distance an d darkness for casua l observing . that th e optical axis is actually concentric wit h For deep-sky astro-photography, however , the mechanica l one ; i.e. that th e telescop e i s the requirement s fo r dar k skie s ar e mor e truly set at 90° declination, regardles s of what a critical. Thi s will mean travelling at least 60 to badly adjusted setting circl e migh t say . Whe n 100km from large cities. Th e ground at such a rotating th e scop e i n righ t ascension , Polaris site shoul d hav e fir m soil t o avoi d jogging o r should remai n centered. If not, adjust it bac k misaligning th e telescope when walking around halfway wit h the declinatio n contro l an d the n it. Furthe r consideration s (cal l them luxuries ) re-center it by movin g the entir e telescop e in include A C power , a warm-u p hut , o r altitude o r azimuth . Repea t this procedur e i f comfortable overnight accommodation . necessary. SETTING UP Once th e optica l axi s i s line d u p paralle l The firs t thin g a n amateu r astronome r with th e mechanica l pola r axis , adjus t you r should d o is set up the telescope in the house, declination circl e itsel f s o tha t i t read s 90 ° both wit h th e light s o n an d off , t o becom e exactly. You'v e now calibrated you r dec. circle; familiar with th e procedure. Ther e are usually in future , pola r alignmen t wil l no t requir e th e some simple modifications that will make most above procedure, I f your declination circledoes telescopes much easier to use. Fo r example, try not get out of calibration . to eliminat e loos e nut s an d bolt s b y Once this has been done, the star pattern in "captivating" them in the equipment. I f you can, Figure 1 ma y b e use d t o offse t Polari s th e eliminate the need for tools by aquiring on e of required amount. Thes e adjustments are made the "ho t set-up " boi t kits . Thes e are available by movin g th e entir e telescop e in altitude (b y for Celestro n scopes , for example . Also, yo u adjusting th e latitud e angl e o f th e wedg e o r should alway s have a t leas t one spar e bolt o r mount) o r i n azimut h (b y movin g th e wedge, nut of every size you normally remove. There is pier o r tripo d fro m sid e t o side) . Havin g on e nothing mor e frustrating tha n losin g tha t all - tripod o r pie r le g pointe d sout h help s whe n important wedg e bolt i n the snow or tall grass, trying to raise or lower the scope to set it on the and havin g t o g o hom e withou t usin g th e Pole. telescope. Of course , thi s procedur e assume s you r For visua l observing , th e telescop e nee d finderscope i s very accurately aligned to you r only b e roughly aligne d with Polaris. Thi s will main optics , a n adjustmen t yo u ca n mak e make following a n object easier. Precis e polar during th e da y b y sightin g o n a very distan t alignment i s necessary only i f you intend to use terrestrial object. Mos t finderscopes have fields setting circles ( a practice frowned upon in the of abou t 4° , s o Polari s will hav e to b e moved Edmonton Centre!) , o r i f you ar e going t o d o about 1/4 of afield diameter to one side in order astro-photography. to center the true Celestial Pole. 19 "With a normal (ens the maximum image drift we can tolerate on the film is ISO/ of arc."

ROUGH GEAR S AND REFRACTIO N Typical Flnderscope View Even with yourclock drive running during a long exposure, the stars wil! still trail across the film t o a certai n extent , spoilin g th e photo . Increasing atmospheri c refractio n nea r th e horizon and a misaligned mount are two causes of gradua l imag e drift , bu t shor t ter m erratic motion i s caused by errors in your drive gears. This i s the mos t seriou s problem tha t requires electronic "drive correction." Let' s see how bad it ca n be . If, fo r th e purpose s o f thi s article , w e assume that th e earth rotates once in 24 hours exactly, the n i n 1 secon d o f tim e th e sk y appears to move about 1 5 seconds of arc. Now, from practic e (althoug h i t ca n b e calculated), we know that when using a 28mm or 50mm lens Figure I on a fixed tripod, a n exposure of no more than 10 second s wil l produc e sta r image s wit h n o noticeable trailing . Therefore , th e maximu m PLUGGING I N amount o f imag e drif t w e can tolerate o n th e If AC power is available, simply plug in your film is about 150 " of arc (15" of arcxIOseconds telescope moto r an d observe . I f you r onl y of time) . source of electricity i s a 12 volt car battery, yo u Now lets assume that the telescope drive in will need an inverter to power your scope. Thi s question use s a 6-inc h diamete r driv e gea r unit converts 1 2 V DC t o 11 0 V AC a t 60Hz . (approximately 20-inc h circumference) . I f The hear t o; f every such device is a simple there i s a .001-inch error i n the tooth-to-toot h stepup transformer . Bu t transformer s don' t spacing ( a typica l erro r i n averag e qualit y work on D.C. A n inverter circuit switchesthe12 gears), the resultin g imag e drift'will be: V DC alternately betwee n two ends of a center- tapped windin g o n th e transformer , thu s number o f seconds of ar c i n 360° 4 - number o f "fooling" it into thinking i t is connected to A.C. thousandths i n circumferenc e = 129600 0 / power. Thi s produces a 110V AC/60Hzsquare 20000 = approx . 65" ol arc of image drift per wave output , whic h wil l ru n a standar d thousandth o f an inch gea r error. telescope motor . For visual observing, this i s all yo u reall y Our averag e image drift of 65" of arc from need i n th e wa y o f electronics . Ther e ar e gear erro r alon e i s a sizabl e fractio n o f th e several relativel y inexpensiv e unit s o n th e maximum allowable error of 150". I t begins to market for this purpose: th e Meade #43 inverter become obviou s wh y yo u canno t simpl y trus t (sold at the Planetarium), the Accutrack #2361, your telescope to track your camera across the or the unit from Rober t Little are all examples. sky b y itself . Th e exampl e we gave was for a Astro-photographers, however, will require wide-angle o r norma l 50m m lens . Th e longer an inverte r wit h adjustable frequenc y output . the foca l lengt h o f th e lens , th e mor e i t wil l This i s necessar y fo r guiding , bu t wh y i s magnify tracking errors. With a 200mm lens, for guiding necessary ? example,an imag e drift of no more than 35" or 20 "Better quality gears reduce tracking error by a factor o f 10. '

so can be tolerated. Wit h a 2000mm telescope, Questar drive corrector fo r example . 3.5" i s the maximum . A typica l driv e correcto r draw s abou t 1 In better quality gears, the actual errors are ampere from a 12 V DC supply. Eve n in winter less tha n .0001-inc h ove r period s o f u p t o this should not be enough to drain a car battery. several minutes , reducin g imag e drif t b y a However, t o fre e yoursel f fro m th e car , a factor of 10. (I n our case, this means a tracking motorcycle battery o r a small sealed lead-aci d error o f onl y 6.5" , comparabl e t o th e battery may be used, B e sure to get at least a 10 requirements fo r photograph y wit h ver y lon g Amp-Hour capacit y uni t an d kee p i t charged . focal lengths. ) Also , the larger the diameter of {Charge after use , store i n cool place , charge the driv e gear , the smaller the error. Yo u can once a month i f no t used. ) see why critica l astro-photographers try to get For portabl e astro-photography , yo u wil l the bes t possibl e driv e syste m fo r thei r need no t onl y th e driv e corrector bu t als o an telescopes sinc e i t mean s less guidin g an d illuminated reticl e guidin g eyepiec e an d (fo r sharper photos . photography through the telescope itself) some sort of off-axis guider or separate guide scope. KEEPING COMFORTABLE FIfiure 2 If settin g u p an d usin g you r portabl e telescope is to b e at all enjoyable, you mus t be multivibrator switch comfortable. The important thing to remember (and it' s amazing how many people forget this) is that it gets co/dat night. Be sure to overdress. If yo u alway s ge t col d a t eac h observin g session, the hobby will soon lose its appeal and satisfaction. 110 VAC outpu t Frankly, long underwea r i s excellent, even in summer , a s i t beat s havin g to wea r a bulk y coat. Heav y pant s ar e strongly recommende d car batter y as well as warm boots, a touque and parka with hood for winter. A hat is a valuable item even in summer a s the bod y ca n los e u p to 50% of it s warmth through the head. Heav y mitts are nice, but even cloth gloves help a lot. (Forge t leather Simplified Drive Corrector Circui t -- it doesn't insulate well.) In general, remember that yo u wl ! be doing almos t nothin g physica l To actuall y guid e th e telescope , th e for several hours at the coldest time of the day. photographer use s an electronic drive corector A FE W LAST HINTS with "fast" and "slow" buttons to vary thespeed In astro-photography, record every photo. of the motor. Thes e buttons usually changethe To do this, a pencil is best as pens can freeze up frequency of the inverter from 60Hz to 72Hz and in winter. Tw o flashlights are convenient, one 48Hz respectively . Thi s give s a 20% change, dim re d light fo r preservin g night vision whe n which is about the limit of a 60Hz synchronous reading charts , AstroCards, etc. , an d a brigh t motor. Beyon d this the motor will stall. Fo r the white flashlight fo r packing up by. {No w where "slow" function , th e powe r t o th e moto r may did I drop tha t bol t ??) actually b e shu t off ; thi s i s a featur e o f th e Good observing , an d see you a t the Sites.

21 Cliff Holmes , conference organizer

Some of th e crowd of 800 who attended . RIVERSIDE ROUNDUP

From Ma y 24 to 26 , 800 people converged o n Cam p Oakes in the Sa n Bernadino Mountains of California for a weekend of amateu r astronomy. The weather was unusually cold but the A 16 " Newtonia n o n an An elaborate set-up for friendship was warm and the AstroWorks mount . astro-photography. event a great success for the organizers and for those who attended. All photo s by Alan Dyer

Refractors are still very popular. Thts The Ingenious "bowling ball" David Levy's folded refractor features a Brandt 8" objective. telescope. that "talks. "

22 The annua l Riverside gathering is probably one of the finest events in the world of amateur astronomy. Ifs lik e an eclipse -- yo u hav e to be there at least once in your lifetime .

Richard Berr y (left ) o f Astronomy.

Leo Henzl' s bargain table, one of many.

Robert Co x o f Telescope Making magazine

David Chandler with a sample of his 12" Volkscope. Robert Little , Criterion representative .

Brad Walli s and Robert Provln . Ben Mayer and his band of blinkers. ot th e ploncUiriu m uue hov e liftof f !

On July 8, the Edmonto n Cit y Council named the proposed Space Sciences Centre as the official cit y projec t t o commemorate Alberta's 75t h Anniversary. Wit h thi s approval goes a grant o f $5,000,000. After year s o f planning an d negotiations, the projec t i s off th e ground !

July 8 wa s a n unusua l da y a t th e from Cit y Hall that the Council had voted 8 to 3 Planetarium. Whil e cleanin g out the basemen t to fun d th e ne w Planetariu m an d Spac e storage area we came across a box of dusty old Sciences Centre. Almos t twenty years after the films. On e o f the m wa s a memorabl e item , Q.E.P. was first opened, th e long-held drea m of showing rar e footag e o f th e Roya l Visi t t o many — a drea m o f buildin g a ne w majo r Coronation Par k i n 1959 , and th e actua l sod - planetarium for Edmonto n wa s realized. turning ceremon y fo r th e Quee n Elizabet h But while i t might see m like the battle has Planetarium. There were also flickering scenes been won, the July 8 approval was only the first of one of the first programmes presented in the step. Th e wor k i n designin g th e buildin g i n theatre, wit h a youthfu l Ia n Maclenna n detail ha s only jus t begun . Futur e editions of presiding over the evening's event. Stardust wil l featur e progres s report s o n th e Seeing thi s historica l bi t o f fil m wa s a n planning and construction of what will surely be appropriate prelude for what was to come later one o f th e fines t facilitie s i n th e worl d fo r that day . Shortl y afte r noo n wor d came down science education and entertainment.

"That's one smal t ste p fo r City Council , one giant lea p for Edmonton. "

24

rci/c new /

PLANETARIUM SPONSORS SUMMER to promot e astronom y las t Apri l 26 . The first OBSERVING SESSIONS prize wen t t o th e Gran d Rapid s Amateu r On eac h Tuesda y an d Thursda y evening Astronomers Associatio n i n Michigan . Th e throughout Augus t th e Planetariu m wil l b e Edmonton Centr e was one of 6 clubs to win an continuing wit h its series of small-scale public Honorable Mentio n Certificate , however . The observing sessions. Telescopes will be set up in judges were very impressed with STARNIGHT front of the Planetarium to allow the public and 1980 and with Inequality of ourentry. Look fora the patrons of the evening shows to look at the photograph i n th e Augus t issu e o f Sk y an d real sky . The viewing will get underway about Telescope o f th e RAS C displays se t up i n the 10:00 PM , but i t is likely that scopes will be set Planetarium lobby at STARNIGHT. up earlier for some solar observing with scopes CANADIANS WIN AT RIVERSIDE equipped with white-light an d Hydrogen-alpha Five RAS C member s attende d th e 198 0 filters. RASC members are welcome to help out Riverside Telescop e Maker s Conferenc e i n with these sessions, primarily i n helping to set California last May: Ste w Krysko and Alan Dyer up scopes supplied b y the Planetariu m and in from the Edmonto n Centre , Jack Newton and explaining the sights to the public. If you would Leo VanderBy l fro m th e Victori a Centre , an d like t o len d you r assistanc e for a n evening, David Lev y formerl y o f th e Montrea l an d please contac t Planetariu m Communit y Kingston Centres . Thi s i s th e firs t yea r tha t Programmer, Stewar t Krysk o a t wor k there was any Canadian or RASC contingent at (4550119), o r a t hom e (488-1092) . Severa l Riverside. On the othe r hand , RAS C members members hav e already volunteered, bu t some have lon g bee n well-represented a t Steltafane, nights ar e still vacant. the eas t coas t equivalen t o f Riverside . David NO FIRS T PRIZE, BUT AN HONORABLE Levy won a Riverside Merit Award for his unique MENTION talking telescope , a folde d refracto r calle d The Edmonto n Centr e wa s th e onl y Mintaka. Jac k Newton , an d absent membe r of Canadian group to enter the Edmund Scientific the Victoria Centre, Georg e Ball , wo n a Merit "Astronomy Day " competition . A $50 0 priz e Award fo r thei r col d camer a instrument . was awarded to the group with the best project Members o f th e Edmonto n Centr e wil l recal l that at the April General Meeting, Jac k showed several photograph s take n wit h thi s col d camera. Our congratulations to Jack, George, and David! The First Annual Norman W. Edmund Astronomy Award LIGHTNING PLAGUES THIRD ANNUAL S & D On Friday, June 20, a total of only 7 RASC Certificate of Honorable Mention members showe d u p fo r th e Thir d Annua l Summer Solstic e Sacrific e and Debauchery . The stormy weathe r that nigh t ma y have kept more S & D'er s away . Indeed, i t was almost a real huma n sacrific e tha t nigh t a s al l th e celebrants had to flee the top of Buck Mountain at abou t 1:3 0 AM whe n the y wer e confronte d with a ver y activ e thunderstorm. Tent s wer e packed u p b y th e ligh t o f near-continuou s lightning. Earlie r i n th e evening , th e distan t 26 lightning provide d a spectacula r displa y t o must be paid u p member for nex t year. It is the accompany th e solstic e vigil , an d a cheerfu l 1981 due s tha t w e wil l begi n collectin g i n time was had by those few i n attendance. September. Last year' s S & D gaine d widesprea d recognition latel y wit h th e reprintin g o f ou r ACROSS CANADA 1979 post-Debauchery repor t i n the May, 1980 The Victori a Centr e i s contemplatin g th e issue of The Reflector. This newsletter goes out construction o f a mobil e 20 " reflector . Th e to som e 700 0 member s o f th e Astronomica l heart o f th e telescop e woul d b e an f/4 mirror , League in the U.S. The editors used our writeup the blank for which i s already owned by centre as an inspiration fo r simila r events they hoped member Le o VanderBy l Th e Vancouve r to encourage around th e States. Centre is well into their Centre 50th Anniversary With the unplanned departur e Friday night project, with various small committees lookin g of everyon e fro m Buc k Mountain , no one was into aspects o f developing their new observing left fo r th e work part y schedule d fo r th e nex t site. For now, that include s th e construction o f day, Saturday , June 21 . However, Dav e Beale an observing hut , obtaining electri c power, and and Co . returne d o n Sunda y afternoo n an d incorporating th e Centr e unde r B.C . cleared another large section of the Lower Site. regulations. Greg g Winte r o f th e Vancouver Two weeks later, on Saturday, July 5, a group of Centre i s experimentin g wit h ga s hyper - 7 Centre members continued th e work. Almost sensitization o f fil m fo r astro-photogaphy . the entir e Lowe r Sit e i s now cleare d (abou t 1 Rumour has it that Gregg was in fact using the acre i n size) , wit h mos t o f th e brus h eithe r apparatus on Sunday, May 18 when 3 or 4 large burned o r stacke d fo r firewood . Late r thi s explosions were hear d i n the Vancouver area, summer w e hop e t o acquir e th e grave l but official s repor t tha t h e was nowher e nea r necessary for some road improvements, and to Mt. St . Helen s Th e Winnipe g Centr e also begin clearin g th e Uppe r Site . Contac t Dav e reports som e strikin g sunset s followin g th e Beale (474-0811) or Ted Cadien (463-1703 ) for initial St . Helen s eruptio n Oddl y enough , the dates of future work sessions. the publicly-owned Goldendal e Observatory in Washington Stat e di d no t receiv e an y as h WE DIDN' T QUIT E REAC H 100 fallout fro m eithe r th e Ma y 1 8 o r Ma y 2 5 As o f July 1 , 1980, the membershi p coun t eruptions. Operation s wen t o n a s usual , bu t for the Edmonton Centre stood at 99 members! with smalle r tha n norma l turnout s a t thei r Last year's total was 97. While we gained many public lecture s 'Scope, th e seldom-see n new member s thi s year , a n almos t equa l newsletter o f th e Toront o Centre arrived with number o f ol d member s failed to rene w thei r news o f ho w Toront o Centr e member s ca n membership, leavin g u s wit h almos t zer o apply fo r th e ne w RAS C Messie r Certificat e growth. initiated b y Edmonton Th e Hamilton Centr e Members wh o joine d lat e i n th e is currentl y collectin g donations fro m it s membership seaso n (i.e . afte r Apri l o r so) , members toward the purchase of the 17.5" f/4.5 ' PLEASE TAKE NOTE : set of optics from Coulter. Thi s will replace the While we will begin collecting membership 10" scop e no w house d i n thei r ne w Centr e fees again in the fall, everyone who is a member observatory Th e Ottaw a Centre' s radi o now will continu e t o receiv e Stardust an d the telescope ha s bee n use d b y Centr e member s National RAS C publication s unti l December , during th e sprin g t o recor d a number o f solar 1980. However, to receive all 1981 publications, flares. Report s o f thei r observation s ar e including the 198 1 Observer's Handbook, you contained i n recent issue s of Astronotes. 27 look boc k tim e and IO O year / ag o August, 1930 : well suite d fo r observatio n tha t "stil l furthe r increase i n their number s i s desirable. " "The Cap e Times of Jun e 1 6 contains a n article entitled "Sout h Africa for Astronomers," July 1880 : by Dr . R.T.A . Innes , who recentl y retire d from "If an y ligh t whateve r ha s it s intensit y the directorshi p o f th e Unio n Observatory , increased the effect on the eye is to add to the Johannesburg. H e trace s th e presen t sensation a certain yellow element which I have astronomical development i n that regio n to Si r accurately defined by an experiment (Am, Jour. David Gill's invitation to European astronomers Sc/., Apri;, 1877, vol. xiii, p.247). I t follows that if to visi t th e Cap e mor e tha n fort y years ago. two star s ar e o f unequa l brightnes s the y wil l Prof. Kapteyn' s visi t ther e resulte d i n th e appear of different colours unless the qualities formation o f th e Cap e Photographi c of the two light s have a peculiar relation to one ; Prof , d e Sitte r bega n ther e another; an d th e brighte r wil l usuall y b e the the importan t wor k o n Jupiter' s satellite s that yellower. Accordingly , i f w e refe r t o Mr . he has lately brought to completion; he has also Burnham's list s o f binarie s w e fin d tha t concluded a n arrangemen t fo r Leyde n although difference s o f colou r ar e s o littl e astronomers t o visi t Johannesbur g distinguished that three-quarters of all the pairs Observatory an d vic e versa . Thre e Nort h are considered t o be of the same colour, ye t of American observatorie s hav e establishe d the twenty-four pair s which differ in brightness branches in South Africa: Harvard has a branch by tw o magnitude s o r over , no t on e i s at Bloemfonte i n; Yal e ha s on e a t considered t o hav e components o f th e sam e Johannesburg; an d Dr . Abbo t o f th e colour. An d o f th e forty-two pair s whic h ar e Smithsonian Institution , has established asolar said t o b e o f differen t color al l bu t tw o hav e observatory at Bukkaros near Windhoek, being more yellow i n the brighter, so much so indeed led to this by advice from Dr. Innes.... Dr. Innes that it is possible to suppose that the difference notes that ther e are already mor e astronomers of brightness is the chief cause of the difference per thousand of the inhabitants in Sout h Africa than i n any other country; and the climate is so Edited from Nature. « Tony Whyte

NOTICE TO READERS Due to increase d printing and mailing costs, the cover price of Stardust ha s been increased from 35C to 50C effective with this issue . The number o f issues printed per year has been reduced from 1 1 to 10 . One issu e will now cove r the Doc./Jan . period- I t nov / takes about Uvo v;e3l;s of volunteer time to typeset and layout each issue, time that will not be available at year's end due to the bus y Planetariu m schedule at that time. The annual subscriptio n fe e for Stardust wil l also be increased from $3.5 0 to $4.50effective October 1 , 1930 . All ne w subscriptions and renewals received before that date will be honored at the ol d rat e of $3.5Q/year. We trust that our subscribers will appreciate the need for these changes. Of course, members of the Edmonto n Centr e will be unaffected by the price increases . They will continue to receive Stardust a s a benefit of their $20.0 0 membership fe e ($12.00 for youths). Membership fee s in the Centre remai n unchange d fo r 1980/81 .

28 uihotV up ? the cygriu / are a

Now that the perpetual twilight has ended we can fully appreciate the summer Milky Way. What better plac e t o start than the prominent of Cygnus. Within Cygnus lie some of the best-known objects in the sky, such as the Vei l Nebul a an d the Nort h American Nebula .

CLASS I composing al l thes e section s ar e muc h mor e The North American (NGC 7000 ) is a bright spectacular. nebulous area located just southeast of ( The othe r CLAS S II object s are rathe r a Cygni) . I t i s very large , reasonabl y bright , bright planetaries . NG C 682 6 i s the "Blinkin g and easil y located i n a pair o f binocular s i n a Planetary." It' s a fairly bright , blu e planetary , dark sky. For this reaso n I have chosen i t as a which will seem to disappear from your field of CLASS f object; but b e warned — in a telescope view whe n you loo k directly a t it, leaving only this objec t i s nex t to invisible , being s o larg e the brigh t centra l star . Averted vision reveals and very diffuse . Wit h a nebular filter, though, the nebul a bu t makes the star disappear. NG C the "Gulf o f Mexico" area can be distinguished 7027 is not quite as bright or large as 6826, but is easily. easier t o find . I t form s an equilateral triangl e The othe r CLAS S I object s ar e the two with the stars £ an d $ Cygni . NGC 6826, on Messiers withi n th e boundarie s o f Cygnus . the othe r hand , sit s u p i n norther n Cygnus , Both o f these are open clusters, M29 and M39. toward i Cygni . Also, there is some questio n M39 is the brighte r and larger of the two. It lies of whethe r NG C 702 7 i s actually a planetary. toward th e easter n edge o f Cygnus , about 3 ° The Webb Society Observer's Handbook, Vol 2. west o f Ta , M29 is a bit fainter, but somewhat lists it a s a very starlike emission nebula . easier to find, lyin g close to the middl e sta r in the Norther n Cros s (

CLASS I

Mag. Size Type

M29 7 7 ' OC • \ ^ M39 5 30 ' OC I i , L^ ^^ NGC 700 0 N 1 ^Jl

CLASS II CLASS II I

Mag. Size Type Mag. Size Type

NGC 682 6 8.8 25 " PL NGC 688 4 12 5 7 " P L NGC 702 7 9 18"X1 1 PL \C 5117 1 3 2 " P L NGC 6960 - — N NGC 689 4 1 4 44 " P L NGC 6992/5 N the /olo r /y/te m

Mercury: i s at elongation low in the east on the Jupiter: set s about two hour s after the su n at morning o f Jul y 31. the beginning o f the summer, and is too close to the sun to b e seen by the end of August. Venus: reache s greatest brillianc y on July 21 , and greatest elongation from thesun on August Saturn: i s lo w i n th e wes t afte r sunse t thi s 24. Venu s remain s i n th e mornin g sk y summer. ^ - Mar k teender s throughout th e summer. Mars: no w distan t an d therefor e small , Mar s For further information concernin g th e planets gradually sink s int o th e sunse t durin g th e this month , pleas e consul t th e Observer's summer. Handbook. 30 /peciol event / the Perseid meteorswarm Al l of theevening On Sunday , Augus t 1 0 ther e i s a n annula r sky planet s have disappeared, being to o close eclipse of the sun, but only visible in the Pacific to the sun for observation Venu s is brilliant and in South America . On this continent, onl y in the morning sky, however, reaching greatest the south-west U.S . will see the partial eclipse. elongation fro m th e su n o n Augus t 2 4 O n Save those slightly used welding filter s for the Monday, Augus t 2 5 th e moo n undergoe s a annular eclips e o f May , 198 4 Monday , penumbral eclipse,startingat7:41 PM MDTand August 1 1 i s th e pea k nigh t fo r th e Persei d ending at 11:2 0 PM MDT. See if you can detect meteor shower, when up to 60 meteors per hour any darkenin g o f th e moo n a t all ! A pai r o f will b e visible . Fewe r meteor s wil l b e see n binoculars i s best . I f yo u wer e o n th e moo n Sunday evenin g and at our Observing Session during this event you would see a partial eclipse scheduled fo r Saturday , August 9 at Buck. Be of the sun by the earth Whil e there is little in sure t o tak e a t leas t on e nigh t to si t bac k and the wa y of special celestial events this month , watch th e sk y for a n hour o r so. The Perseids early Augus t an d earl y Septembe r ar e grea t have bee n ver y activ e lately , du e t o th e times fo r explorin g deep-sk y object s i n th e approach o f the parent comet whic h spawned summer constellations and early fall sky. ob/erving report /

OBSERVING O N PLATEAU MOUNTAI N On th e lon g weekend o f Ma y 16-19 , Dave Beale, Darrel l Cross , Crai g Makarowsk i and I went dow n t o Platea u Mountain , southwes t of Calgary, to do some dark sky observing. (Thi s site is a large, flat plateau at about 8000 ft. above sea level) . O n th e two night s tha t wer e clear; each of u s saw at least a few objects before the wind forced us to retreat to a van or tent. A t this time o f the month , the summer Milky Way was making it s wa y ove r th e horizon . This , combined wit h the altitude of Plateau Mountain allowed u s such sights as the dark lanes in the Trifid Nebula (M20), the large open clusters M6 in suc h object s a s the Trifi d Nebula , and th e and M7 , an d th e notoriousl y fain t globula r Lagoon Nebul a (M8) . Man y o f th e brighte r cluster NG C 589 7 i n Libra . A s the Sagittariu s nebulae an d sta r cluster s i n th e Sagittariu s region ros e higher , th e Milk y Wa y became an region were easily seen in a pair of binoculars or incredible sight, with the Great Rift and Central a finder scope. Al l i n all, i t was well worth the Bulge easily see n with the naked eye. Some of 200 mile plu s driv e t o Platea u Mountain, to do the hal f doze n o r so Calgary Centr e member s some observin g a t a reall y dar k sit e an d t o who joined us that weekend had hauled along a escape the annual plagu e o f summer twilight . Celestron 14 , which reveale d incredibl e detai l — Dav e Holmgre n 31 ob/erving activitie s

OBSERVING SESSIONS Observing activities get underway again as perpetual twilight comes to an end for another year. Th e principl e observin g sessio n fo r August i s scheduled fo r Saturday , August 9 at Buck Mountain . A fe w earl y Persei d meteors should b e visible that night, though the peak of the showe r i s no t unti l Monda y night . Thi s should b e a great year for th e Perseid s as the shower occurs at new moon, Grou p observing sessions wil l als o b e scheduled fo r Saturday, Sept. 6 an d Saturday , Sept . 1 3 a t Buc k Mountain. S o mar k the m o n you r calendar . Don't forgot August and September are the best months for the work observing, so try to mak e the most of them this parties at year. Fo r more information, pleas e phone me. Buck Mtn. and OBSERVER'S CORNERS the QEP's On Monday , Ma y 26 , Andre w Low e summer presented a n excellen t tal k o n astro - observing photography illustrate d wit h man y fin e sessions. examples of hi s work. Th e June O.C. featured See p.2 6 for the "Dobsonian Debate", or whether or not the more details. Centre could (or should) build a large telescope for Centr e use . Needles s to say, it was a lively meeting. Chec k the item in this issue titled The Dobsonian Project fo r informatio n o n th e outcome o f this meeting . Coming up , an Observer's Corner meetin g will be held Monday , August 25 starting at 8:00 PM. I t will feature a slide talk from Tony Whyte on th e recen t RAS C Genera l Assembl y i n Halifax, includin g new s o f result s o f thei r observing competition . Ther e shoul d als o be for /cil e lots o f report s an d photograph s fro m th e August observing sessions, so bring along your FOR SALE : 80m m Car l Wetzla r refractor wit h slides! clock drive . Phon e Larr y a t Wed. to Sun. afte r 5 PM. Askin g $500.00. ~ Dave Holmgren (436-2398 ) FOR SALE : Celestro n C9 0 wit h wedg e an d tripod. Rarel y used. Askin g $750.00. Contac t DEADLINE FOR : Kjell Bronson , Entrance , Alberta , TO E ORO, o r Sept. issu e -- Aug. 11 phone (Evenings). Oct. issue — Sept. 8 DISCOVER ThE UNIVERSE

* monthly general meetings * monthl y observers group meetings * regula r grou p observing session s * us e of the Ellerslie Observator y * th e annual RASC Observers Handbook * STARDUST * th e RASC Journal and Newsletter * fre e admission to all Planetarium shows

ANNUAL FEES: $20.00 (Adults) $12.00 (Youths under 18) u/iih RoyAl AsTRONOMJCAl

SociEiy Centre Executive President Te d Cadien of CANAC! A Vice-President Dav e Belcher Treasurer Me l Rankin EDMONTON Secretary Ton y Whyt e Observing CENTRE Coordinator Dave Holmgre n

For more Information, call one o f the above people . STARDUST EDMONTON CENTRE, Royal Astronomical Society of Canada c/o Queen Elizabeth Planetarium 10th Floor, C.N. Tower Edmonton, Alberta T5J OK1

GENERAL MEETING Monday, Sept. 8 at 8:00 PM Music Room, Edm. Public Library SPEAKER AND TOPIC : To B e Announce d

OBSERVER'S CORNER Monday, August 25 at 8:00 PM RM.445, Physics BIdg., U.of A. SPEAKER AND TOPIC : Mr. Tony Whyt e - - "The 1980 RAS C General Assembl y i n Halifax " plus Misc. Observing Report s and Astro-Photograph s

OBSERVING SESSIONS Saturday, August 9 Buck Mountain Sat., Sept.6and Sept.13 Buck Mountain See the ma p in the June issu e fo r direction s o r phon e Dav e Holmgre n at 436-239 8

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