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Show .Bureau watches for celestial wonders 11,1 urf'1"0'01'0'0 1 1 Smithsonian Newt Servlct Photo courtety ol Smithsonian Aitrophyslcal Observatory In 1963, Comet Ikeya-Seki was so bright that it was visible even during the day. Its tail was 77 million miles long when this picture was snapped by the Smithsonian Astrophysical Observatory station in New Mexico. The comet was named after two Japanese observers who reported their discovery to the Central Bureau for Astronomical Telegrams within 15 minutes of each other. This "sungrazer" is not expected back for another 880 years. By William Waller Smithsonian News Service CAMBRIDGE, MASS. In the heavens, as on the Earth, the unexpected unex-pected can occur at any time. Without warning, a fast-moving . comet can dramatically brighten, a previously unidentified asteroid can briefly come into view or an otherwise undistinguished star can suddenly explode into a dazzling nova. Alerting the world's astronomers to these new and often short-lived celestial wonders is the task of the Central Bureau for Astronomical Telegrams, an international in-ternational clearinghouse for the hottest astronomical news fit to print. For scores of skywatchers around the glode, the century-old Telegram Bureau, now operated by the Smithsonian Institution for the International Astronomical Union, has become an indispensable early-warning system for the scientific community. Receiving and diseminating information on all new celestial discoveries and, in some cases, determining who will get credit for the finds, the Telegram formation, the Telegram Bureau's real bread-and-butter is news about comets. Comets are sometimes defined as "dirty snowballs" hardpacked i congolmerations of frozen gases and dust where eccentric orbits around the sun bring them precariously close to the sun's vaporizing rays. The solar radiation causes the comet's icy outer shell to vaporize into a long stream of gas and dust, sometimes millions of miles long. "Comets, even the faint ones, have always held a special fascination for amateur astronomers," Marsden says. This fascination is in part due to the unique tradition of naming comets after their discoverers. No other astronomical objects ob-jects are so named. Usually, the naming process is fairly straightforward. "If all goes well, it's a first-come, first-come, first-served situation," Marsden says. "However, if two or three claims of discovery are submitted within a few hours of each other, we give a combined name." But when more than three claims are received, the Bureau is forced to limit the designation to the first three names. "Though somewhat unfair," Marsden admits, "it has to be done. After all, even three names in a row is a mouthful to pronounce." Perhaps the most problematic episode of comet-naming came in 1975, when two comets were discovered almost simultaneously. The first temporarily designated 1975j, had three Japanese discoverers within 70 minutes. It was formally dubbed "Comet Mori-Sato-Fujikawa." The second, temporarily designated 1975k, had five discoverers within 30 minutes. Alas, the last two discoverers missed their chance for fame, and the final designation became "Comet Suzuki-Saigusa-Mori." Incidentally, In-cidentally, Hiro-Aki Mori's discovery of two comets within 70 minutes was the first time anyone had discovered two successive comets in such a short time. Because of such situations, Marsden emphasizes that the only good way to report a discovery is via telegram. In fact, to ensure that a discoverer receives credit for finding fin-ding a comet, a telegram with date and time clearly marked is absolutely essential. (The Central Bureau's TWX number is: 710-320-6842.) Besides tending to comets, moons and novae via the IAU's Telegram Bureau, Marsden also shepherds the Minor Planet Center, the official recipient and certifier of all asteroid observations. Asteroids, or minor planets, are small, primarily rocky bodies that orbit the sun between Mars and Jupiter and are thought to be relics of the early solar system. "In a typical year, we receive observations of about 1,000 unidentified asteroid candidates, as well as several thousand observations of already known asteroids," Marsden says. Since 1801 when astronomers started keeping track 2,321 distinct asteroids have been catalogued in the "definitive list." Of these, only 12 have been . lost from view. "Right now, we are identifying about 100 new members a year," Marsden comments. com-ments. Once numbered and catalogued, each new asteroid is named by its discoverer after 1 someone else. Although less ego-satisfying, this procedure can be just as much fun as the comet-naming comet-naming practice. For example, John Huchra, an astronomer at the Smithsonian Astrophysical Observatory, Ob-servatory, named his asteroid discovery after Asmodeus, the Babylonian god of lust. Bureau plays a vital role in international astronomy. "We have subscribers throughout the world from the United States to the People's Republic of China, from New Caledonia to Barbados,' says Dr. Brian Marsden, the Smithsonian astronomer who serves as Bureau director. "And, with our telegraph service, we can alert virtually all of them within 24 hours of a discovery." Over the past 12 years, Marsden has become synonymous with the high-speed communications com-munications service headquartered at the Smithsonian Astrophysical Observatory Ob-servatory here in Cambridge, Mass. A spirited Britisher, he runs an essentially one-man one-man show, using TWX machines, one in his observatory office and the other neatly tucked into his study at home. On these machines, Marsden receives astronomical news around the clock from observers around the world. After quickly checking and refining the raw reports of discoveries, Marsden sends out "observing alert" messages via coded telegrams to his main subscribers, primarily the world's major observatories. ob-servatories. Later usually within a day he recomposes the telegrams into printed versions, the official "IAU Circulars." More comprehensive and more readable, these 3-by-5 announcement cards go by mail to a much broader group, including amateur ' astronomers, libraries and news organizations. Because of its rapid and accurate coverage, the Telegram Bureau often breaks some of the most exciting new comets, two Jovian moons and at least seven Saturnian moons as well as a handful of supernova explosions in distant galaxies. Although, it carries a wide range of astronomical in- """" y" Comets have often been associated with impending doom. This illustration depicts a comet broadside over Constantinopole in 1556. To the artist, there may have been some connection between the comet's appearance and an earthquake which struck the city about the same time and caused several buildings to collapse. |
