A. Dollfus, Observatoire de Paris, reports that the observation on 1979 Nov. 1 of an outer ring of Saturn (cf. IAUC 3426) has been confirmed on several plates taken on 1980 Jan. 29 with the 1-m reflector at Meudon. The lineament extends westward from ring A up to 7 Saturn radii. Potential observers of satellite phenomena are advised that ephemerides from February to April are available from: Bureau des Longitudes, Groupe Satellites, 77 Avenue Denfert-Rochereau, F-75014 Paris, France. Coefficients for the development of the coordinates in Chebyshev polynomials are given. The coordinates are differential with respect to Saturn, in the mean equatorial system, and have a geocentric precision of ~ 0".02. D. Pascu, U.S. Naval Observatory, reports the detection of a possible new satellite, designated 1980 S 1. Its weighted mean position, derived from three exposures with the 0.66-m refractor over a 10-min interval centered on Feb. 19.2402 UT, was in the ring plane, 24".63 west of the center of Saturn. The magnitude, comparable to that of Saturn VII (Hyperion), was thus about 14. Supplementing the note on IAUC 3417, J. Van Allen et al. (1980, Science 207, 415) have reported further new satellites as follows: 1979 S3 (suspected, but interpretation of the signature is ambiguous), radial distance from the center of Saturn 2.82 Rs; 1979 S 4 (which may be a longitudinally extended signature of 1979 S 2), distance 2.522 Rs; 1979 S 5 (firmly established), distance 2.343 Rs; and 1979 S 6 (which may be a longitudinally extended signature of 1979 S 5), distance 2.350 R5. There was no trace of 1966 S 1, the object that has previously been called Saturn X (Janus).
International Astronomical Union Circular
- Pub Date:
- February 1980