Circular No. 5366 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 SUPERNOVA 1991bc IN UGC 2691 Robert H. McNaught, Anglo-Australian Observatory, reports his discovery of a supernova (mag about 16) on a J plate taken by M. Hartley with the U.K. Schmidt Telescope on Oct. 12.7 UT. The super- nova appears in UGC 2691, in the arm connecting the two galaxies of this interacting pair, but much closer to the brighter, northern component. SN 1991bc is located at R.A. = 3h18m12s.92, Decl. = -1 13'33".0 (equinox 1950.0, uncertainty 0".3 in each coordinate); offsets from the center of the northern galaxy are 5" east, 6" south. No star of this brightness appears in this position on J or I survey films or on the Palomar Sky Survey. A nearby star of mag about 18 has end figures 14s.49, 2".7. B. Leibundgut, B. Schmidt, and S. Gordon, Center for Astrophysics, report that a spectrogram (range 400-900 nm) obtained Oct. 15 with the Multiple Mirror Tele- scope shows this to be a type-Ia supernova within a week of maximum. The Si II line at 615 nm appears stronger than in SN 1991bb. SUPERNOVAE 1991ay AND 1991bb Leibundgut, Schmidt, and Gordon report further spectroscopic observations (range 400-900 nm) with the MMT. Their observation on Oct. 15.5 UT confirms the classification by Filippenko (IAUC 5365) of SN 1991bb in UGC 2892 as a type-Ia object; the spectrum indicates that the supernova is near maximum. Their observation of SN 1991ay (IAUC 5352, 5356) on Oct. 13.2 UT shows this to be a type-Ia super- nova at about 1 month past its maximum; narrow emission lines from the underlying galaxy indicate a redshift of 0.051. PERIODIC COMET FAYE (1991n) On Oct. 10 D. Rabinowitz, using the Spacewatch telescope at Kitt Peak, detected a very diffuse band of light, some 1'-2' wide and 2 deg long, extending beyond the field-of-view of the scan. J. Scotti confirmed the band with the same telescope the following night and noted that the band could be traced to the head of P/Faye, i.e., for > 10 deg; the band had a uniform width of about 2'. The earth crossed the plane of the comet's orbit on Oct. 13.3 ET. 1991 October 15 Daniel W. E. Green