Bulletin S.R.A.C

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n December r u o J

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t décembre n e m e l p p

u 1991 S

l a n r u o J Royal Astronomical Society of Canada e h t

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n Volume 1 e m e l p p

u Number 6 S BULLa SociétéL Royale d'AEstronomie dTu Canada IN

Auroræ and the Power AURORA CURRENT To SUN System EASTWARD WESTWARD Joe Yurchesyn Senior Project Engineer 100,000 V Nova Scotia Power Corporation Halifax Centre North Pole On March 13th 1989, almost all of Québec’s power system was knocked out for about five hours, with some customers in the dark for close OUTGOING INCOMING to two days. The subsequent Québec Hydro CURRENT CURRENT press report, blaming the previous night’s aurora, was met with a certain degree of scepti- cism by the general public. Believe it or not, our DIRECTION OF ROTATION modern power system is at risk from aurorae. The impact of geomagnetic storms on man- MAGNETOTAIL made systems has been chronicled for almost 150 years. It began with spontaneous electric Figure 1. currents being observed on telegraphs in 1846. The first occurrence of a geomagnetic storm The explanation begins with the Sun. A flow solar wind distorts the magnetic field of the Earth affecting a power system was on March 24th, of charged particles, called the solar wind, is and stretches it out as a long cylindrical shaped 1940, in New York City. continuously streaming away from the Sun. This structure pointing away from the Sun called the magnetotail. In so doing, the positive and negative charged particles of the solar wind are AURORA CURRENT separated, with each type going to opposite MAGNETIC FIELD EFFECT sides of the magnetotail. Since opposite charges attract, these particles want to become "un- NORMAL POSITION EARTH'S MAGNETIC separated”. One path that they can follow to FIELD LINE OF MAG. FIELD LINE accomplish this is down the magnetic filed lines (ie. one of...) of the Earth to the upper atmosphere, and through two curved parallel paths to the opposite side of the Earth (and the magnetotail) and AURORA CURRENT then back up to outer space. See figure 1. The MAGNETIC FIELD high altitude part of this current causes the ~ 100 km aurora; the lowest part interaction (altitude ~100 km) affects the power system. EARTH MAGNETIC FIELD LINE DISPLACED BY AURORA Every electrical current has a magnetic field CURRENT MAGNETIC FIELD associated with it. The magnetic field of the auroral current interacts with, and distorts, the Earth’s magnetic field. See figure 2. The movement of the Earth’s magnetic field lines induces NORTH LOOKING EAST (at night...)

Figure 2. (continued on page 2) R.A.S.C. BULLETIN S.R.A.C. - December/décembre 1991 - Page 1 Prices are per issue At the National Council meeting on May 17th, the Canadian advertisers must pay 7% G.S.T. extra following rates and conditions for advertisements Advertiser is to supply black and white copy two in the BULLETIN were approved. months prior to month of publication along with payment in full to the Society c/o the BULLETIN editor. BULLETIN Number of Insertions One copy of each issue of the BULLETIN contain- is a publication of the Royal Astronomical Society Width Height Size 1 to 3 4+ ing the ad will be mailed to the advertiser. of Canada and is distributed together with the 7.5 " 10.0 " 1 page $750 $600 The BULLETIN is mailed bi-monthly, along with the Society’s Journal. It contains articles on curreni Journal to about 4,000 members and subscribers 90% of 7.5 " 5.0 " 1/2 page $480 $375 activities of the Royal Astronomical Society of whom are in Canada. 5.0 " 7.5 " 1/2 page $480 $375 Canada and its Centres across Canada, as well as Classified ads will be charged at the rate of $1 per word 5.0 " 5.0 " 1/3 page $350 $250 articles from members and non-members which with a minimum charge of $20, subject to the same terms 2.5 " 5.0 " 1/6 page $250 $175 as above. are of general interest to members of the Society. Manuscripts (in English or French) should be sub- field. It will not work with DC electricity. Trans- of harmonic voltages. Harmonic voltages are mitted to the Editor at the address below. Inquiries formers normally carry two types of AC current: multiples of 60Hz (e.g. 120Hz, 180Hz, 240 Hz). about the Society should be directed to its National load current, and magnetizing current. The Harmonic voltages can cause misoperation of Office at 136 Dupont Street, Toronto, Ontario, Canada M5R 1V2. magnetizing current is very small (1% of load) relays in protection schemes resulting in errone- and maintains the internal magnetic field neces- ous tripping of healthy equipment. Editor: Patrick M. Kelly sary for the transformer to work. DC current is Harmonic voltages also greatly affect today’s Mailing Address: 2 Arvida Avenue, Halifax, Nova magnetizing current only, and for economic most modern high-tech power system device, Scotia, Canada B3R 1K6 reasons transformers are not designed for the the Static Var Compensator or SVC. SVC’s are E-mail Address: [email protected] FAX: (902) 423-6672 flow of DC current. Even a small DC current can very complicated control devices which raise cause a dramatic increase in the flow of AC and lower the system voltage at high speed to Editorial Staff: Diane Brooks, Harlan Creighton magnetizing current, perhaps more than the damp out oscillations in the power system. In so Rédacteur pour les Centres francais: Marc Gélinas, load current, and possibly more than the coils doing, SVC’s generate their own harmonic 11 Pierre-Ricard, N-D-lle-Perrôt, Québec, Canada are capable of carrying. The immediate result to voltages which are removed by filters. The nor- J7V 8M6 the transformer is the overheating of the internal mal level of system harmonics plus those pro- Printing: University of Toronto Press coils. Also, more magnetic flux is created than duced by the SVC determines the rating of the This publication is printed on recycled paper con- the core is capable of holding. This causes core filters. Abnormally high levels of system har- htaining 50% pre-consumer recycled paper and at heating plus the excess flux spills into places not monics will overload the filters, causing the SVC least 5% post-consumer de-inked fiber. normally designed to carry it, such as the steel to “trip off” when it is needed most. A trip at the Deadline for the February issue is Dec 15th. containment tank. This can cause sufficient wrong time can initiate a total system collapse, heating to blister the tank’s paint. A prolonged just what happened to Québec Hydro. Auroræ and the Power System flow of even a small amount of DC current can If SVC’s have such problems, then one is destroy a transformer. tempted to ask “Why are they used?”, and “Why (continued from page 1) In addition to problems caused for transform- are they so heavily depended upon?”. Well, ers, another problem is created in the power strangely enough, the answer lies not in engi- a voltage in the ground as if the ground was a system. For complicated reasons, the increase neering, but in economics. It is an example wire in a generator. This voltage is about 5 V/km. in magnetizing current flow causes the creation These voltages are direct current (DC), as op- (continued on page 7) posed to the alternating current (AC) delivered to your home. Long transmission lines are electrically (and ORIGIN OF GROUND INDUCED CURRENTS physically) connected to ground through trans- NORMAL POSITION formers. See figure 3 on page 2. The auroral OF MAG. FIELD LINE DIRECTION OF AURORA CURRENT FLOW induced ground voltage causes the ground at each transformer to have a different voltage. lt is as if a giant battery was connected between the DISPLACED MAG. FIELD LINE transformers. The transformer has a high resistance to the normal AC power frequency, but a very low resistance to this DC voltage. The GROUND INDUCED CURRENT / 3 result is a significant flow of DC current into the GIC GIC transformers. The magnitude of this current is IINDUCED GROUND VOLTAGE proportional to the resistance of the ground beneath the transformers. Québec Hydro’s trans- EARTH CURRENT formers, situated on the high resistance bed- WEST LOOKING NORTH rock of the Canadian Shield, are particularly susceptible to this type of current flow. RESISTANCE OF ELECT. EQUIP.

Transformers have coils of wire wrapped RESISTANCE OF BEDROCK around an iron core which holds the magnetic

R.A.S.C. BULLETIN S.R.A.C. - December/décembre 1991 - Page 2 The weather, while not perfect, was reason- 36 inch telescope to yourself for an hour? Much Alberta Star Party 1991 able. Afternoon thundershowers cleared off in later, John Dobson comes out to see what we’re Glen Hawley the evenings, only annoying us slightly with looking at. Someone at the eyepiece describes Calgary Centre some dewing problems. A large group of sun- NGC 6888, the Crescent Nebula, as a big egg. spots was slowly creeping out of sight around John scurries (and I mean scurries) up the The 1991 Alberta Star Party was a joint effort the limb of the Sun, but enough of them re- ladder to see for himself. After a moment, he of the Lethbridge Astronomy Club, and the Cal- mained to make a worthwhile view through solar announces definitively, “This is no hen’s egg - gary and Edmonton Centres of the Royal Astro- filters during the day. The sky brightness caused it’s a snake’s egg!” That settles that. nomical Society of Canada. In past years, each by the high sunspot levels did have a deleterious Midweek, the air is steady: Murray sees of these groups had taken turns hosting the effect on the nighttime views, as one might Encke’s Division in his 12.5 inch and Bryce has event at different locations in southern Alberta. expect. the central star in the Ring at 620x in his 14 inch. The once and future permanent site is now the While most of the attendees were from Al- Thursday night is calm and clear all night. Murray Waterton Heritage Campground, a private facil- berta, some came from B.C., Montana, Sas- finds an arc of the Veil Nebula in his 6x30 Zeiss ity just north of the Waterton Park gates, off katchewan and Manitoba. We hope to be able to binoculars, unfiltered. Laced with dark tenta- Highway 6. Lethbridge handled local logistics, welcome more people from eastern Canada cles, M24, the great star cloud in Sagittarius, is Calgary the registrations, and Edmonton the and the United States, and plan on a bit more magnificent in my 12.5 inch. True to form Alister speakers, and this arrangement seems to have publicizing of what has been till now a basically Ling and Steve (a friend visiting from Australia) µ worked very well. We intend to continue our local event. spend three hours on an almost invisible plan- cooperative efforts in years to come. etary with an even more invisible galaxy super- The party is held each year in late August Mount Kobau ’91 imposed on its edge. Dawn offers the subtlest of colours; greens, yellows, blues, violets. We try near the time of the New Moon; typically on the Dave Clyburn weekend following the Mount Kobau Star Party. out Steve’s 8x50 Fujinon binoculars and know Edmonton Centre what we want for Christmas. If the Waterton site lacks the superb skies of reprinted from Stardust Kobau, it does have some little conveniences Friday night is cloudy, but after an all-nighter, that Kobau lacks, such as hot showers, a small After two wet Mount Kobau Star Parties in a no one seems too upset. Showers on Saturday grocery store, heated outdoor pool, and flush row, why would 140 or so people drive hundreds afternoon threaten the telescope-making com- toilets (a particular relief after the rather aro- of miles to take the chance of getting drenched petition, but they abate. Bob Drew’s 20 inch f/4 matic “one-hole-long-drop” facilities at Kobau) again? The place seems to get in your blood. aluminium “Heavy Metal Thunder” takes a prize. Daytime activities in the park are only a few The mountain can offer tranquil beauty one hour The evening is cloudy; it’s starting to feel like last minutes drive away. These things make as- and raging thunderstorms the next. The sky at year again. A few people pack up and leave. tronomy more fun for the rest of the family. our observing site, well east of Edmonton can Around 11:00 P.M., skies clear and the air is Most of the participants camped in the get very dark, but the brilliant Milky Way spilling very transparent. The 36 inch is back in the campground overflow area, which the across the heavens at Kobau is another matter States, but it’s replaced by a splendid 25 inch f/ campground management set aside for our entirely. For long periods, my telescope is aban- 5 with a Galaxy Optics mirror brought by the exclusive use. Serious dark sky fanatics had doned; its field of view is much too narrow for MacMillan Planetarium in Vancouver. their own area, outside the campground and up what can be seen here. We try out Bob’s new 20 inch. The Veil is the hill a little ways, while lovers of civilized After a couple of years of attending, the stunning. Guest speakers Al Dyer and Terence amenities could set up their RV’s in the main confusion of tents, R.V.’s and telescopes re- Dickinson share that view. Near NGC 891, the campground, where they could have electricity veals its own order: Craig McCaw’s 17.5 inch field is riddled with galaxies. NGC 7008 shows and water hook-ups for a modest extra fee. joins the Calgary group, near Ted Pigeon’s 20 a wealth of detail. The dawn comes all too early, Registration of $20.00 for the star party did not inch Cassegrain. Lucien Kemble, Dan Lazar but then provides its own rewards. For the dark cover camping fees, which started at $8.00 per and Murray and Joanne Paulson are also in their of the Moon in August, Mount Kobau was again µ night. Those who did not wish to actually camp familiar spots on the second tier. John Casino’s the place to be. out could go to the town of Waterton, which is 36 inch is below. Above, on the road to the One board member found perplexing the located right inside the park, to stay in one of the summit, the Vancouver observers are on the scientific view that the north and south motels there. west side (joined by the Breckenridges) on the poles have changed places several times in Around 150 registrants showed up this year, concrete pad while Bryce Heartwell’s 14 inch the history of our planet. She wondered and T-shirt sales were brisk. The traditional and my tepee are in their usual places to the why scientists couldn’t make up their minds! Saturday supper was cooked on a four metre east. Linda and Robin Utter are everywhere at long barbecue-on-wheels which showed up once. The American group who form Refractor She also found evolution unconvincing be- towed behind a pick-up truck full of groceries. A Alley are missing this year as the Table Moun- cause she could not imagine how asexual good two dozen volunteers were recruited holus- tain Star Party is on at the same time south of the life forms could evolve into male and female bolus from the three sponsoring groups, to sup- border, but appropriately, their spot remains forms. Nonetheless, she said that she was plement the Lethbridge cooking team. There vacant throughout the week. in favour of science because it had made were burgers for the kids, steaks for the adults, On Monday night, I wander down the hill to possible cosmetics and skin creams. corn-on-the-cob, baked potatos, an enormous check out the 36 inch. John Casino is busy doing vat of salad, and an excellent selection of vari- something else but graciously offers me, a National Science Foundation, ous home baked desserts. stranger, its use. Now, where else do you get a Conference on Science Education (1986) R.A.S.C. BULLETIN S.R.A.C. - December/décembre 1991 - Page 3 In addition to just the right ascension and The second selection accessed from the MAIN MICRO-GUIDER: A declination display, the Micro-Guider also has a MENU is the SELECT MENU. The SELECT built-in database of celestial objects. The data- MENU is used to select an object to find (it is also Computerized Setting base contains 17 bright alignment stars, the 110 used by the alignment function described above). Messier objects, the entire 7 840 object NGC It consists of a sub-menu used to enter whether Circle/Database Device database, and the eight planets. Five “user” a star, deep sky object, or a planet is to be David J. Lane objects also allow for the storage of transient selected. If a star is selected, the user is to enter Halifax Centre objects such as comets or minor planets. the number of the star (as shown on the front of OPERATION: the Micro-Guider) directly on the keypad. The INTRODUCTION: The operation of the Micro-Guider is very star database is mainly used in the alignment Micro-Guider, as I have named it, is a device straightforward because it is entirely menu driven. function of the SET MENU. If a planet is se- which I have designed and built to provide a When the Micro-Guider is turned on, the MAIN lected, the Micro-Guider uses the date and time telescope with digital setting circles, complete MENU becomes active. The MAIN MENU is from the built-in clock to calculate the planet’s with a database of 7 975 celestial objects. It is used to access four functions, the first being the position. All nine planets are supported; if the designed to provide many of the features pro- SET MENU. user enters a 3 (meaning the Earth), the calcu- vided by commercially available units. The SET MENU is used to align the Micro- lated position is somewhat inaccurate as Micro- As well as describing the Micro-Guider’s func- Guider, set the built-in clock, and also to control Guider simply instructs the user to look down! tionality and software, this article will also dis- several programmable settings. The alignment The deep sky database is subdivided into Messier cuss a future project which will enhance the function asks the user to select two objects from and NGC objects, with the object’s catalogue Micro-Guider’s capability. The author would be the built-in database and to point the telescope number entered directly on the keypad. more than pleased to provide more detailed to these two objects. After this procedure is The third selection accessed from the MAIN information than is provided here, for readers complete, the Micro- Guider is able to determine MENU is the INFO screen. It displays the known who wish to consider building the device them- the right ascension and declination that the information (object number, right ascension, selves. A blank printed circuit board and EPROM telescope is pointed to, until the mount base is declination, object type, and magnitude) for the (electrically programmable read-only memory) moved or the Micro-Guider is turned off. currently selected object. chips are available at cost from the author. I can be reached at the following “addresses”: David J. Lane 26 Randall Avenue Apt. 4 Halifax, Nova Scotia Canada B3M 1E2 Phone:(902) 443-5989 Compuserve ID: 71601,247 Internet: [email protected] DESCRIPTION: The Micro-Guider is a self-contained device which connects to a telescope by using two optical shaft encoders, one attached to each rotational axis. The optical encoders translate the movement of the telescope into electrical signals which are interpreted by the Micro-Guid- er’s on-board microprocessor. The Micro-Guider is very user-friendly, incor- porating a large two line by twenty column liquid crystal display (LCD), and a sixteen button keypad for the user to interact with. In addition, the built-in software is entirely menu-driven. As is normal practice with modern digital setting circles, the Micro-Guider uses two ini- tially known coordinates to align itself. This allows it to work equally well with equatorial or alt-azimuth mounted telescopes, since it does not require polar alignment or mount levelling. Once aligned, it uses the elapsed time and the azimuth and altitude to calculate the current right ascension and declination based on a complex trigonometric algorithm. The Micro-Guider, shown attached to the author’s Meade 2120 telescope. Photo by the author. R.A.S.C. BULLETIN S.R.A.C. - December/décembre 1991 - Page 4 The last selection of the MAIN MENU is the Another major part of the program is the The user objects are entered by the user and GUIDE MODE. The GUIDE MODE is the main object database and planet calculation func- stored in non-volatile memory. operational screen of the Micro-Guider. This is tions. As mentioned earlier, there is a perma- Using the basic software functions just de- the screen where the telescope’s coordinates nent database of alignment stars (seventeen), scribed, a menu structure was created to act as are shown. The GUIDE MODE has two screens: Messier objects (110), and NGC objects (7 740). the user interface for the Micro- Guider, com- right ascension/declination screen and azimuth/ The database contains the Epoch 2000.0 coor- pleting the software. altitude screen. The first screen displays the dinates to a precision of 1/20 of a degree, the FUTURE PROJECT: right ascension and declination in which the object type, and the brightness of the object (if A future project which I intend to undertake is telescope is currently pointed and the right as- known) to the nearest tenth of a magnitude. to enhance the Micro-Guider’s capabilities by cension and declination of the currently se- The Messier database was obtained from the adding the ability for it to drive a Dobsonian lected object. The telescope’s coordinates are Compuserve computer network’s ASTRO FO- telescope in right ascension so that it will track updated whenever the telescope is moved or if RUM (provided by Darrell Green). The NGC the stars. For obvious reasons, the Micro-Guider a sufficient amount of time has elapsed which database was derived from the NGC2000.0 disk cannot drive a Dobsonian telescope in right makes a re-calculation necessary. The selected marketed by Sky Publishing. In all cases the ascension with a single motor in one axis (as is object is brought into the telescope’s field of databases had to be compressed into a size of done with an equatorially mounted telescope), view by moving the telescope such that the 6 bytes per object in order to allow all of the thus it must be accomplished by controlling two telescope’s coordinates equal that of the se- objects to fit into the 64k of available object independent motors. The motors that I intend to lected object. The second screen does the same memory. There is space available for about use are stepping motors attached to the azimuth thing, only using altitude and azimuth instead of 3000 more objects, which in the future I may use and altitude axis driven at calculated rates of right ascension and declination. for the brightest Index Catalogue objects. speed and direction to simulate a single motion SOFTWARE: The planets are calculated using the algo- in right ascension. This is the method used by The Micro-Guider’s hardware is basically a rithm described in the book: “Practical Astronomy most modern professional observatories. dedicated computer, thus the software formed a With Your Calculator” (equation 50). The algo- The motors will be controlled based on the major part of the effort in designing this device rithm is not “super” accurate, but was a trade off following method. The Micro-Guider always and thus reflects greatly in its functionality. The between speed, program size, and accuracy. (continued on page 7) software was written primarily in the C program- ming language. When writing the software for this project, I did not have many of the luxuries available to most programmers when using a conventional desk- top computer. I had to start from absolute scratch, by writing all of the software which scans the keypad, outputs to the LCD display, and other functions most programmers take for granted. The first major part of the software is the optical encoder and coordinate conversion rou- tines. The optical encoders are read by the software at a rate of 2 048 times per second. Each optical encoder produces two signals which are used to determine the direction of motion of each shaft. These two signals when combined, form a “grey code”. A grey code is a binary sequence whereby only one bit (or signal) can change from one state to the next. The software detects a change in the encoder signals, then interprets the grey codes to determine the new azimuth and altitude of the telescope given the current and previous grey codes. Given the azimuth and altitude of the telescope, the Micro-Guider then uses the trigonometric algorithm described by Toshimi Taki of Japan in Sky and Telescope’s Astronomical Computing column (February 1989). This algorithm, given two initial coordinates at known times, can be used to convert a telescope’s azimuth and altitude into right ascension and declination and vice-versa. Consult the article A close-up view of the Micro-Guide. Note that for entering negative declinations the “D” key is for details of this algorithm. used as the keypad has no minus key. Photo by the author. R.A.S.C. BULLETIN S.R.A.C. - December/décembre 1991 - Page 5 building what may be Canada’s largest amateur Canadian “Starfest” telescope; and David Levy, Canadian comet NOVA EAST ’91 Comes of Age hunter extraordinaire, now up to twelve comets Doug Pitcairn at the time of writing. Special treats have been Halifax Centre Cathy Cresswell the continuous forty-eight hour coverage of Ottawa Centre Voyager’s Neptune encounter with live telephone This year’s Nova East was held on the Labour linkage with Terry Dickinson at the Jet Propul- Day weekend, August 30th to September 2nd in This year’s August 10th weekend marked the sion Laboratories; the comet panel discussion New Brunswick’s Fundy National Park. It was celebration of the tenth year for Starfest, one of with Canadian comet discoverers David Levy, hoped that the late date would increase our the most popular Canadian amateur astronomi- RoIf Meier and Doug George; and the on-site chances of a clear sky. For the last three Nova cal conventions. Starfest saw first light in 1982 optical quality survey and testing marathon by Easts, the skies have been poor until the last with about twenty-five participants from south- Peter Ceravolo of Telescope Making magazine. night, and then fate has allowed everyone a ern Ontario. It was conceived by Andreas Gada This 10th year celebration brought a very night of prime observing. This year saw a con- and Bonnie Bird, founders of the North York special program and about 275 registrants. The tinuation of this somewhat perplexing trend. Astronomical Association. The N.Y.A.A. is an guest speakers for the Saturday evening talk Sunday night was indeed clear, and until the active observing group started in 1980 in To- were Tony Hallas and Daphne Mount of Oakview, twenty-three day old moon rose about midnight, ronto and currently has about forty-five mem- California, who delighted us with their incredible Fundy’s legendary dark sky allowed a feast of bers. Club equipment includes 16" f/5 and 12.5" astrophotos. The daytime program included observing. f/6 Newtonians, a CCD camera and a surplus special talks on optical design by Roland Chris- Friday saw a so-so day turn into a cloudy Baker Schmidt meteor camera. ten of Astro-Physics and on telescope fabrica- night. Several dozen people showed up for The Starfest convention is held annually at tion by Rocky Cimarusti of Celestron Interna- public viewing anyway. You’ve got to admire the River Place Campground near Mount For- tional. Other presentations were given by their enthusiasm! Then it was back to the camp- est, Ontario. The Friday evening program con- Andreas Gada on the successful N.Y.A.A. Baja site for several slide talks. sists of informal slide talks under the marquis eclipse trip; Michael Watson on the R.A.S.C. Saturday was rather wet with intermittent dry tent and observing until dawn. Saturday has tent eclipse trip; comet discoverer Doug George and spells. The corn boil and whatever roast was talks morning and afternoon, a swap table, electronics engineer Bob Sandness on CCD postponed until the more promising Sunday, as commercial vendors, a catered dinner at the comparisons; and Dr. John Percy, Dean of was the scope set up. We did get everybody to site, door prize draws and a special evening talk Science and Erindale Campus of the University fill out a registration form, and there was a brisk followed by observing. For other family mem- of Toronto on contributions that serious ama- sale of NE ’91 T-shirts, featuring artwork by our bers there is a pool and playground. teurs can make to astronomy. very own Mary Lou Whitehorne. The scene Over the past ten years, Starfest speakers There was a commemorative cake cutting depicted was a typical NE ’91 one: two rac- have included many well-known amateurs and ceremony Saturday evening and a number of coons, eating corn and playing inside some professionals: Terry Dickinson, noted Canadian special award presentations were made to Star- hapless astronomer’s Dobsonian scope! In ad- observer and author of the popular Night watch fest contributors from the past decade. Prize dition, the members of the Cape Breton As- and other books; Dr. Fred Lossing of the Ottawa certificates were awarded to winners of Star- tronomy Club (Motto: “We put the party back in Centre, a Stellafane judge for many years and a fest’s first astrophotography competition. Best Star Party!”) sold anyone and everyone a fa- designer of the 16" Newtonian telescope that of Show honours went to Ottawa’s Doug George. mous and very rare (till next printing) C.B.A.S. was used to discover five Canadian comets; Dr. Both Friday and Saturday nights were cool hat. Tom Bolton of the David Dunlap Observatory, and clear and afforded everyone spectacular Sunday the sky was broken cloud until mid- discoverer of the X-ray source Cygnus X-1; observing through a myriad of telescopes ranged day, when the clouds departed and left us a Steve Dodson of the acclaimed Science North throughout the campground. It was a special classic clear sky. The corn was consumed and center in Sudbury, Ontario, who is currently ending to a special celebration. µ astronomical babble was the order of the day. The telescopes were displayed, along with as- sorted gidgets and gadgets. The “Coulter gang” dominated one section of the field, while the large refractors towered overhead. The aperture range was two to thirteen inches, with Tom Anderson’s (Saint John Astronomical Society) King Kong taking first place in the monster category (12" f/9 on an equatorial mount). The clear skies were no accident. A Styrofoam and cardboard telescope was burned in effigy that evening as a sacrifice to the cloud gods, while amateurs stood around chanting “Clear skies!”. Laugh, oh ye of little faith, but the clouds parted and the photons were good. The slide talks do a nice job of filling in the Starfest founders Andreas Gada and Bonnie Bird with the anniversary cake. Photo by the author. cloudy nights. This year’s talks included cover- R.A.S.C. BULLETIN S.R.A.C. - December/décembre 1991 - Page 6 age of the eclipse in Baja, Stellafane and the about $300,000 per km, plus the substation at Auroræ and the Power System G.A., stamps with an astronomical theme, as each end. For a typical line length of 400 km, well as an assortment of astrophotos from sev- that’s $120,000,000 for the lines plus several eral amateurs. We also distributed several small (continued from page 2) million for the two substation terminals. An SVC door prizes, including an excellent framed photo where a complicated, but elegant solution is giving a similar increase in transmission capac- of Comet Levy (taken at last year’s Nova East) cheaper then the brute force approach. ity costs about $12,000,000. Although the SVC by Greg Palman of Maine’s Penobscot Valley The modern power system has evolved into option results in higher system losses, the SVC Amateur Astronomers. Also given away was a one where generating equipment is remote from is still more attractive economically. year’s subscription to The Starry Messenger. load centres and interconnected by long trans- To date, the worst power system disruption We hope to expand upon the door prizes next mission lines. On any system, the power that occurred at 2:45 A.M. on March 13th, 1989, year as we are considering starting a small can flow is inversely proportional to transmis- when virtually all of the province of Québec was registration fee. sion resistance. That is to say, the lower the plunged into darkness. Québec Hydro’s system One thing noticed this year was a drop in the resistance (i.e. more lines),the greater the power collapse can be attributed to the loss of SVC’s attendance from the Halifax Centre. The weather flow. However, on an AC system, things are a due to high levels of harmonic voltages. At that no doubt was a contributing factor. Also con- little more complicated. Power flow is also pro- time, the Québec system was sustaining a con- spicuous by their absence were any members portional to the angle between the sending and nected load of 21 350 MW. Nine hours later, from the two P.E.I. clubs, Charlottetown and receiving voltages. On an AC system, sixty 83% of its forecast load had been restored. The Athena. The attendance from both south of the times per second, the voltage rises from zero to remaining 17% represents about 3 600 MW, a border and from the Saint John club were both a maximum in one direction, decreases back to little more than twice the peak load for Nova up. Next year’s Nova East, (August 28th -31st), zero, rises to maximum in the opposite direction Scotia Power! is ideally timed with a three day crescent moon and decreases to zero again. Believe it or not, The Sun goes through cycles where the aver- showing off to the public, then getting out of the when the AC voltage is at a maximum at your age strength of the solar wind varies. The last way for an all night observing session. µhouse, it is not at a maximum at the generating strong cycle was in the late 1950’s, during a time station. There, it is actually past maximum and when power systems were small and weakly Micro-Guider on its way back to zero! This time difference interconnected. This made them relatively in- between the voltage at your house and the sensitive to the effects of the aurora. Today’s (continued from page 5) generating station can be described as the power system spans thousands of kilometres, “angle” between the sending and receiving knows the current right ascension and declina- depends on SVC’s to damp out instability, and is voltages. Power flow is regulated by controlling tion (coordinates on the sky) and the azimuth much more sensitive to the aurora. this angle. There is a practical maximum at and altitude (coordinates of the telescope). It The aurora problem is not new, but high solar which this angle can be maintained, however a also can calculate a future azimuth and altitude activity in recent years has demonstrated how larger angle can be tolerated if an SVC is used. of the telescope for a fictitious object placed at susceptible the modern power system has be- This is where the economics come in. There the current declination but with an increased come. Currently, we are at the mercy of mag- are two choices available to provide increased right ascension (thus at a time in the near netic storms, but the next period of low solar power flow: build more lines, or build an SVC. A future). Knowing the current azimuth and alti- activity will provide time for continuing research high voltage transmission line typically costs µ tude and a future azimuth and altitude and the to offer possible solutions. time difference between them, the Micro-Guider can calculate the rate and direction at which to drive each of the two motors. If this approach proves successful and tracks sufficiently well to allow for time exposure pho- tography, the next logical step is to add a third axis at the eyepiece to correct for field rotation at the film plane. This final step would open up some exciting possibilities by allowing portable and stable large aperture telescopes to be used for deep sky astrophotography without their normal massive equatorial mountings. The author would be very interested in hear- ing from Dobsonian owners who would like to collaborate on this project. ACKNOWLEDGEMENTS: I would like to acknowledge my employer, OCEANROUTES SEIMAC where I work as Professor Emeritus J.E. Kennedy at the podium in the lecture theatre of the Convention Centre, Montevideo, Uruguay, participating in the official opening ceremonies of the International electronics design manager, for allowing me to Colloquium on the Astronomical Culture in Modern Society on July 16th, 1991. Claude Hareau use their computer-aided design system. I would de Estrada, on his left, served as the official English-Spanish translator. also like to thank Nathan Cohen, for designing The following evening, Professor Kennedy, a former President of the R.A.S.C. and currently the and machining the encoder mounts. µ representative of the Saskatoon Centre on National Council delivered the invited main lecture. R.A.S.C. BULLETIN S.R.A.C. - December/décembre 1991 - Page 7 – La nuit du grand OVNI de Montréal, F4. N Index – Volume 1, 1991 – L’Astronomie en couleur, Au6. N.A.S.A., Poor N.A.S.A., Doug Pitcairn, Ap1. Gibbons, Clive, Letter to the Editor, J2. National Science Foundation, quote, D3. – Seeing The Light, J1. News Notes: Advertising Rates, J4, D2; International Astro- Note that the individual issues are identified H by letters as follows: F=February, Ap=April, nomical Youth Camp 1991, F5; Ie Annuaire Astronomique, Au2, O2; Officers Appointed, Ap3; R.A.S.C. Promotional J=June, Au=August, O=October, Haasdyk, Ulrich, Trip to Totality: One Person’s Experience, O6. Items, Ap3; Saskatoon Member Speaks in Uruguay, D7. D=December. Thus a page referecne of J7 Halley’s Comet Time Capsule Sealed, Patrick Kelly, Au6. News Reaches the Colony, Ed Kennedy, O8. refers to page 7 of the June issue. Halliday, Ian, Peter MacKenzie Millman, 1906-1990, Ap3. NOVA EAST ’91, Doug Pitcairn, D6. Hawley, Glen, Calling All RASCals!, O8. O A – Alberta Star Party 1991, D3. Occultation par Pallas, Alain Roussel, J8. Head, Mel, Calling All RASCals!, O8. Offthe Deep End: Two Amateurs Try the Real Thing, Mary A Canadians Pre-War Comet, Philip Mozel, F7. Hewitt, Susan, A Call for More Scientific Truth in Product Lou Whitehorne and Chris Brown, Ap4. A Call for More Scientific Truth in Product Warning Labels, Warning Labels, O1. P Susan Hewitt and Edward Subitzky, O1. How Astronomers Captured an Asteroid, John Howell, Au4. A Saskatchewan Name in the Skies, Richard D. Vanderberg, Howell, John, How Astronomers Captured an Asteroid, Au4. Peter MacKenzie Millman, 1906-1990, lan Halliday, Ap3. Au8. Hugo, Victor, quote, F4. Pitcairn, Doug, Amateurs Needed to Observe Nothing!, J4. Across the R.A.S.C.: Edmonton, Ap8; Halifax, Au2; Hamil- Hymec, J. Allen, quote, Ap2. – N.A.S.A., Poor N.A.S.A., Ap1. ton, Ap8; London, J6; Vancouver, Ap8, J6, O2; Victoria, I – NOVA EAST ’91, D6. J6; Windsor, J6. Planets in the Palm of Your Hand, Brian McCullough, J4. Introducing Children to Astronomy, Sylvia Smith, Ap6. Q Ah, the Amateur Enjoys, Alister Ling, Fl. K Alberta Star Party 1991, Glen Hawley, D3. Quotes, “Astronomy is the most ancient O2; “In the path Amateurs Needed to Observe Nothing!, Doug Pitcairn, J4. Kelly, Patrick, My First Editorial, F1. of a total eclipse...”, O8; “It’s our U.F.O....”, Ap2; “One An Encounter With Totality, Bruce W. Shier, O4. – My Second Editorial, Apl. board member found perplexing...”, D3; “This is the Astronomie le long du Saint-Laurent, Marc A. Gélinas, J8. – Halley’s Comet Time Capsule Sealed, Au6. excellent foppery of the world...”, Au5; “What shall be the Astronomy Day in Montréal, Mario Caluori, F3. Kennedy, J.E., T.W. Webb’s Classic Text, F7. lot...”, F2; “Where the telescope ends...”, F4. Astronomy Day in Montréal, Mario Caluori, Au7. – News Reaches the Colony, O8. R Astronomy Day in Six Cities, Steve Dodson, Au3. Kingston Centre Hosts a Real Blast!, Bill Broderick, Au7. Ramblings of an Armchair Astronomer, Jim Low, J7. Astronomy Workshop 1991, Dave Clyburn, F6. Kunej, Zeljko, Letter to the Editor, Ap2. Reyahi, Bassel A., Letter to the Editor, J2. Aurora and the Power System, Joe Vurchesyn, D1. L B – Letter to the Editor, Au2. La dichotomie de Venus en 1989-1990, Marc A. Gélinas, Reflections, F1, Ap1, J1, Au1. Belleru, Sergei, Letter to the Editor, Ap2. Ap6 (erratum, J8). Roussel, Alain, Occultation par Pallas, J8. Bernstein, Loule, What is Heaven? A Personal Perspective, La nuit du grand OVNI de Montréal, Marc A. Gdlinas, F4. Ryan, Dennis, Discovery of an Observing Site, J6. Aul. L’Astronomie en couleur, Marc A. Gélinas, Au6. S Binary Star Observer’s Group Formed, Ronald C. Tanguay, Lane, David J., MICRO-GUIDER: A Computerized Setting Saxon, Greg, The Incredible Blinking Reticle, J3. F8. Circle/Database Device, D4. Seeing The Light, Clive Gibbons, J1. Breckenridge, Catherine, Letter to the Editor, Ap2. Ledger, E., quote, F2. Segal, Brian, Long Time, No See, F3. Broderick, Bill, Kingston Centre Hosts a Real Blast!, Au7. Letters to the Editor, Sergei Belleru (Astronomical Glasnost), Shakespeare, William, quote. Au5. Brown, Chris, Off the Deep End: Two Amateurs Try the Real Ap2; Catherine Breckenridge (This is our Real Address), Shier, Bruce W., An Encounter With Totality, O4. Thing, Ap4. Ap2; Mario Caluori (Astronomy Day in Montréal), F2; Simison, Jack, Letter to the Editor, F2. Brown, Peter, Meteors: Why Not?, Au5. Alan Dyer (New Format Liked). Au2; D.J. Fitzgerald (I’m C Not Dead Yet!), F2; Clive Gibbons (Testing Jupiter’s Smith, Sylvia, Introducing Children to Astronomy, Ap6. Disk), J2; Zeljko Kunej (Courageous Astronomer), Ap2; Some Observations of the Zodiacal Light, Alister Ling, Au8. Calling All RASCals!, Glen Hawley and Mel Head, O8. Alister Ling (A Cure for Some Headlights),J1 ; Alister Ling Spinney, Steven, The 1991 General Assembly, O3. Caluori, Mario, Astronomy Day in Montréal, F3. (The Mazatlan Zenith Curse?), F2; Todd Lohvinenko Subitzky, Edward, A Call for More Scientific Truth in Product – Astronomy Day in Montréal, Au7. (Palms Up), O2; Jim Low (The “Old” Name’s History), Warning Labels, O1. – Letter to the Editor, F2. Au2; Bassel A. Reyahi (A Mystery of Procyon), Au2; T Can the Disk of Jupiter Be Glimpsed With the Naked Eye?, Bassel A. Reyahi (Astronomy Under Attack), J2; Jack Tanguay, Ronald C., Binary Star Observer’s Group Formed, Roland G. Dechesne, Ap7. Simison (A Society First!?), F2; Gregory L. Zentz (Hu- F8. Canadian “Starfest” Comes of Age, Cathy Cresswell, D6. mour Wanted), F2. The Incredible Blinking Reticle, Greg Saxon, J3. Clyburn, Dave, Astronomy Workshop 1991, F6. Ling, Alister, Ah, the Amateur Enjoys, Fl. The 1991 General Assembly, Steven Spinney, O3. – Mount Kobau ‘91, D3. – Letter to the Editor, F2. The R.A.S.C. Eclipse Expedition, Dan Falk, O4. Cresswell, Cathy, Canadian “Starfest” Comes of Age, D6. D – Letter to the Editor, Jl. Trip to Totality: One Person’s Experience, Ulrich Haasdyk, – Some Observations of the Zodiacal Light, Au8. O6. Davie, Kathie, Ways to Increase Disabled Participation, F4. Todd Lohvinenko, Letter to the Editor, O2. T.W. Webb’s Classic Text, J.E. Kennedy, F7. Davie, Wayne, Ways to Increase Disabled Participation, F4. Long Time, No See, Brian Segal, F3. V Dechesne, Roland G. Can the Disk of Jupiter Be Glimpsed Low, Jim, Letter to the Editor, Au2. Vanderberg, Richard D., A Saskatchewan Name in the With the Naked Eye?, Ap7. – Ramblings of an Armchair Astronomer, J7. Skies, Au8. Discovery of an Observing Site, Dennis Ryan, J6. Luther, Martin, quote, O2. Dodson, Steve, Astronomy Day in Six Cities, Au3. M W Dyer, Alan, Letter to the Editor, Au2. Ways to Increase Disabled Participation, Wayne and Kathie Major U.S. Research University Discovers New Element!!, Davie, F4. E Au5. Weil, Andrew, quote, O8. Escadrille exceptionnelle de météores, Gaetan Morissette, McCullough, Brian, Planets in the Palm of Your Hand, J4. What is Heaven? A Personal Perspective, Louie Bernstein, J8. Meteors: Why Not?, Peter Brown, Au5. Au1. F MICRO-GUIDER: A Computerized Setting Circle/Database Whitehorne, Mary Lou, Off the Deep End: Two Amateurs Try Device, David J. Lane, D4. Falk, Dan, The R.A.S.C. Eclipse Expedition, O4. the Real Thing, Ap4. Fitzgerald, D.J., Letter to the Editor, F2. Morissette, Gaetan, Escadrille exceptionnelle de météores, Y G J8. Mount Kobau ’91, Dave Clyburn, D3. Yurchesyn, Joe, Auroræ and the Power System, D1. Gélinas, Marc A., Astronomie le long du Saint-Laurent, J8. Mozel, Philip, A Canadian’s Pre-War Comet, F7. Z – La dichotomie de Venus en 1989-1990. Ap6 (erratum, My First Editorial, Patrick Kelly, F1. Zentz, Gregory L., Letter to the Editor, F2. µ J8). My Second Editorial, Patrick Kelly, Ap1. R.A.S.C. BULLETIN S.R.A.C. - December/décembre 1991 - Page 8