Circular No. 5396 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Telephone 617-495-7244/7440/7444 (for emergency use only) TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505 MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN 1991 WA R. H. McNaught reports the following measurements of a fast- moving asteroidal object discovered by himself on a U.K. Schmidt Telescope plate taken by M. A. Read and K. S. Russell (the Dec. 1-4 observations were obtained by McNaught with the Uppsala Southern Schmidt telescope): 1991 UT R.A. (1950) Decl. V Observer Nov. 29.45312 1 59 14.93 -21 12 05.4 16 Read Dec. 1.42488 1 56 10.98 -14 58 48.0 McNaught 1.55171 1 55 59.42 -14 36 29.9 " 1.55775 1 55 59.03 -14 35 25.2 " 2.49549 1 54 50.78 -11 56 59.7 " 2.61539 1 54 41.53 -11 37 31.4 " 4.44760 1 52 56.44 - 7 00 45.9 " 4.45315 1 52 56.12 - 6 59 56.6 " Orbital elements from the above observations by G. V. Williams: T = 1991 Sept.26.426 ET Peri. = 241.835 e = 0.64254 Node = 66.089 1950.0 q = 0.56389 AU Incl. = 39.673 a = 1.57748 AU n = 0.497458 P = 1.98 years 1991 ET R.A. (1950) Decl. Delta r V Nov. 30 1 58.30 -19 23.7 0.260 1.160 16.1 Dec. 5 1 52.50 - 5 44.9 10 1 50.13 + 3 37.4 0.386 1.267 16.9 15 1 49.90 +10 09.6 20 1 51.17 +14 53.5 0.548 1.368 17.9 25 1 53.56 +18 27.4 30 1 56.83 +21 14.5 0.727 1.465 18.6 PERIODIC COMET SCHWASSMANN-WACHMANN 1 H. Kosai, National Astronomical Observatory of Japan, communi- cates that M. Tsumura (Oishi Station) has observed an outburst of this comet on a photograph taken Dec. 2.528 UT; the comet appeared stellar, of mag 12-13, suggesting an early phase of outburst. S. Larson, University of Arizona, independently observed the outburst on Dec. 4, noting a fan tail at p.a. about 100 deg; two 30-min spectrograms (range 300-850 nm) show only continuum. 1991 December 4 Daniel W. E. Green