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Comets for Canada

by David H. Levy, Author and Comet Discoverer

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Until 1965 December 17, comet hunting through a telescope was a distinctly non-Canadian sport. Before then, however, Jim Low of the Montreal Centre set up an ingenious binocular-based search program based on dividing the sky into 438 areas, most of them 10 x 10 degrees in area. Jim built upon the 175 Milky Way nova search areas in the AAVSO program, adding areas 176 to 438 as specific comet search areas. The idea was that areas would be assigned to members of, at first, the Montreal Centre, but later, as the standing committee for observational activities was formed in the mid-1960s, to members of the RASC all over the country. Although no comets were discovered this way, I am still actively using these areas in my photographic comet search by subdividing them into 1 x 1 degree CCD fields.

On 1965 December 17, I began my telescopic comet search program, which eventually became the earliest Canadian telescopic comet hunt that eventually succeeded in discovering a comet. Nine years later, Sidney van den Bergh became the first Canadian to discover a comet; his comet appeared on a photographic plate taken in the U.S. In 1978, Rolf Meier became the first Canadian to discover a comet from Canada; his program has since yielded four discoveries: 1978f (C/1978 H1), 1979i (C/1979 S1), 1980q (C/1980 V1), and 1984o (C/1984 S1). Two months after his fourth and most recent find, I discovered Comet 1984t, the first of 21 discoveries plus two independent finds below:

Visually, with backyard telescope:

  • Comet Hartley-IRAS 1983v, P/1983 V1, 1983 November 28
  • Comet Levy-Rudenko, 1984t, C/1984 V1, 1984 November 14
  • Comet Levy, 1987a, C/1987 A1, 1987 January 5
  • Comet Levy, 1987y, C/1987 T1, 1987 October 11
  • Comet Levy, 1988e, C/1988 F1, 1988 March 19
  • Comet Okazaki-Levy-Rudenko, 1989r, C/1989 Q1, 1989 August 25
  • Comet Levy, 1990c, C/1990 K1, 1990 May 20 (This widely visible object was considered the most spectacular since Halley in 1986).
  • Periodic Comet Levy, P/1991 L3, 1991 June 14
  • Comet Takamizawa-Levy, C/1994 G1, 1994 April 15

Photographically, as part of team of Eugene and Carolyn Shoemaker and David Levy:

  • Periodic Comet Shoemaker-Levy 1, 1990o, P/1990 V1
  • Periodic Comet Shoemaker-Levy 2, 1990p, 137P/1990 UL3
  • Comet Shoemaker-Levy, 1991d C/1991 B1
  • Periodic Comet Shoemaker-Levy 3, 1991e, 129P/1991 C1
  • Periodic Comet Shoemaker-Levy 4, 1991f, 118P/1991 C2
  • Periodic Comet Shoemaker-Levy 5, 1991z, 145P/1991 T1
  • Comet Shoemaker-Levy, 1991a1, C/1991 T2
  • Periodic Comet Shoemaker-Levy 6, 1991b1, P/1991 V1
  • Periodic Comet Shoemaker-Levy 7, 1991d1, 138P/1991 V2
  • Periodic Comet Shoemaker-Levy 8, 1992f, 135P/1992 G2
  • Periodic Comet Shoemaker-Levy 9, 1993e, D/1993 F2 (This comet crashed into Jupiter in 1994, resulting in the most dramatic events ever seen on another world).
  • Comet Shoemaker-Levy, 1993h, C/1993 K1
  • Comet Shoemaker-Levy, 1994d, C/1994 E2
  • Periodic Comet Shoemaker 4, 1994k, P/1994 J3

In 1990, Doug George discovered Skorichenko-George (C/1989 Y1) from Ottawa, using the same telescope that Rolf Meier had used for his finds. In January 1995, Robert Jedicke discovered his first comet, P/1995 A1, as part of the Spacewatch Survey in Arizona. It holds the distinction of being the first comet to be designated with the new system, P/1995 A1, instead of the old, which would have been 1995a. Jedicke followed that up with a second, P/1996 A1, a year later. In August 2001 at a star party in Saskatchewan, Vance Petriew discovered comet P/2001 Q2, near The Crab Nebula.

Future of visual discoveries

Comet hunting has utterly changed in the 37 years since I started comet hunting in 1965. Back then, the threat to visual searches was from photographic surveys, which were succeeding in finding most of the comets. However, these efforts were concentrating on the sky at opposition to the Sun, and not terribly thoroughly at that, leaving many comets available for visual observers. Even after the enormous productivity of the great Palomar photographic surveys of the 1980s and 1990s - surveys specifically designed to discover comets and asteroids - until a few years ago it still seemed possible for comets to be found visually.

Although it is certainly still possible to discover a comet visually, it is far more difficult to do so than it was even a few years ago. Some comets happen to come in at a shallow angle to the Sun that hides them from the big surveys. But the date and time of the last visual comet discovery is approaching. I still believe that there will always be comets for the amateur to seek and find through his or her visual telescope. It's harder than it used to be, and many searchers will give up. In 1967, Robert Burnham Jr., who discovered comets both physically and photographically, advised me that "If you hunt long enough, stay away from the galaxies in Virgo, and never give up, some day you will find a comet." I think this advice still holds, although that "some day" could be decades into the future for most searchers.

As you hunt for comets, remember that it isn't a good idea to have the discovery of a new comet your only goal. In 1997, Leif Robinson, then-editor of Sky & Telescope, came down pretty hard on single-minded searchers. "I've never had any great admiration for comet hunters," he editorialized. "To spend hundreds of hours in failure for each minute of success never seemed like a good deal to me. ... For amateurs there's the allure of getting your name hitched to a star, albeit a hairy one. If you're very lucky, like Thomas Bopp, your name might appear in textbooks for years." If the only reason you spend all this time comet hunting is to find a comet, then Robinson has a point. So did the great Japanese comet hunter Minoru Honda, who discovered 12 comets and 11 novae during his lifetime, in the advice he gave Kaoru Ikeya before the young comet hunter made his first discovery. "If you desperately want to find a new comet, please stop your search because you may never be able to find a new comet. However, if you are content to search the sky without ever experiencing a new comet discovery, please keep searching because someday, you may be able to find a new one." Leslie Peltier, in Starlight Nights, perhaps said it best:

In spite of this increasing competition there always will be comets for the amateur to seek and, in some facets of this work, he still has an advantage. In a given time he can cover far more sky than can the camera, he can know within half an hour the true nature of a suspected object and he can search much closer to the sun in regions which would fog a photographic plate.

Click for a full list of Canadian Comet Catchers