Circular No. 5405 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 1991bi IN NGC 5127 Further to IAUC 5404, C. Pollas reports that the supernova is located at R.A. = 13h21m24s.75, Decl. = +31 49'28".6 (equinox 1950.0). A star of magnitude B = 17.5 has end figures 28s.58, 03".2; another foreground star (B = 12.5) has end figures 14s.15, 51'09".1. S. Benetti, E. Cappellaro, and M. Turatto, Asiago Observatory, communicate: "A spectrogram (range 390-800 nm, resolution 2.0 nm) of SN 1991bi, obtained on Dec. 15.19 UT at the Cima Ekar 1.8-m tele- scope (+ Boller & Chivens spectrograph + CCD), exhibits several broad emission features (the strongest are measured at 462.5, 497.5, 561.0, and 662.3 nm) typical of a type-Ia supernova 3-4 weeks after maximum. However, the absorption feature at about 570.0 nm, usually relatively strong in type-Ia supernovae at this phase, is missing." 5405 Circular No. 5405 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 1991bi IN NGC 5127 Further to IAUC 5404, C. Pollas reports that the supernova is located at R.A. = 13h21m24s.75, Decl. = +31 49'28".6 (equinox 1950.0). A star of magnitude B = 17.5 has end figures 28s.58, 03".2; another foreground star (B = 12.5) has end figures 14s.15, 51'09".1. S. Benetti, E. Cappellaro, and M. Turatto, Asiago Observatory, communicate: "A spectrogram (range 390-800 nm, resolution 2.0 nm) of SN 1991bi, obtained on Dec. 15.19 UT at the Cima Ekar 1.8-m tele- scope (+ Boller & Chivens spectrograph + CCD), exhibits several broad emission features (the strongest are measured at 462.5, 497.5, 561.0, and 662.3 nm) typical of a type-Ia supernova 3-4 weeks after maximum. However, the absorption feature at about 570.0 nm, usually relatively strong in type-Ia supernovae at this phase, is missing." SUPERNOVA 1991bg IN NGC 4374 Benetti et al. also report: "A spectrogram of SN 1991bg was obtained on Dec. 14.15 (instrumentation details as given above). A preliminary reduction of the spectrum shows a very strong Si II line at 617 nm, indicating this to be a type-Ia supernova not far from maximum. Also very strong is the other Si II line at 581 nm, and also present are the S II lines at 534.5 and 550.5 nm. Although the continuum is relatively blue and no Na I D interstellar absorption is visible, there are several similarities with the strongly red- dened SN 1986G in Cen A in the proximity of its maximum: the slow expansion velocity, the strength of Si II lines, and the absence of the emission band at about 410 nm (visible in most of the type-Ia spectra)." GRS 1715-44 N. Lund, S. Brandt, and A. J. Castro-Tirado, on behalf of the Granat WATCH team (Danish Space Research Institute, Lyngby; and Space Research Institute, Moscow), report: "A gamma-ray burst, GRS 1715-44 (R.A. = 17h15m, Decl. = -44.1, equinox 1950.0, error radius 1 deg), was recorded by the WATCH all-sky x-ray monitor on Dec. 9.77 UT. The event contained two pulses with 12-s separation. Follow-up observations are encouraged." 1991 December 16 Daniel W. E. Green