Circular No. 3507 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. TWX 710-320-6842 ASTROGRAM CAM Telephone 617-864-5758 SATELLITES OF JUPITER S. P. Synnott, Voyager Navigation Team, Jet Propulsion Laboratory, informs us that the Voyager 1 observations reported on IAUC 3470 as confirmation of 1979 J 1 in fact refer to another satellite, designated 1979 J 3. Of diameter perhaps 40 km, 1979 J 3 has also been detected in transit across Jupiter in at least half-a-dozen Voyager 2 frames as well, and its revolution period is determined as 7h04m30s +/- 3s. 1979 J 1, of diameter perhaps 25 km, has not been identified in frames other than its discovery ones, and its revolution period remains at 7h09m +/- 1m (Jewitt et al. 1979, Science 206, 951). At the epoch of the Voyager 2 observations (1979 July) 1979 J 1 and 1979 J 3 were separated by about 160o in longitude. Images of the satellite 1979 J 2 have now been identified in both Voyager 1 and Voyager 2 data, and its revolution period has been refined to 16h11m21s.3 +/- 0s.5. SATURN J. Lecacheux and B. Fort, Observatoire de Meudon, report: "CCD observations of the Saturnian E ring on Mar. 16-17 at Pic du Midi lead to a radial structure unlike that proposed on IAUC 3497 by the Space Telescope Wide Field/Planetary Camera Team. In a paper submitted to Icarus on July 10 we note a broad maximum (E1) in density between 4.15 and 4.6 (+/- 0.2) Rs from Saturn; this is roughly midway between Enceladus and Tethys. There is a second, narrower component (E2) near 5.7 Rs, somewhat inside the orbit of Dione. Such a two-component model is supported by quick-look electronographic observations on Feb. 28-29 and Mar. 1. We wish to point out the difficulty of discriminating between stationary condensations that are real components of the rings and transient ring knots due to satellites (1980 S 6, perhaps also 1980 S 13) moving in Dione's orbit or possibly due to similar unknown bodies orbiting at various distances from Saturn's center." NOTICE TO CONTRIBUTORS Contributors are reminded that the recommended way of contacting the Central Bureau is by TWX/telex to the number 710-320-6842 (answerback ASTROGRAM CAM). This number, followed perhaps by "CENTRAL BUREAU FOR ASTRON, CAMBRIDGE, MASS", should also be used for the address in messages sent by telegram or cablegram. 1980 August 26 (3507) Brian G. Marsden
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