Circular No. 4591 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 617-495-7244/7440/7444 MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN SUPERNOVA 1979G IN MCG +01-08-023 A. R. Klemola, Lick Observatory, reports that S. Francic has discovered a stellar object, presumably a supernova, on simultaneous blue and yellow exposures by B. Jones with the 0.5-m Carnegie double astrograph on 1979 Dec. 17.23 UT. The object, of B about 16.5, was located at R.A. = 2h55m48s.63, Decl. = -5D01'08".0 (equinox 1950.0), or 9".4 east and 4".4 south of the nucleus of the galaxy MCG +01-08-023 (mag 15.5). SUPERNOVA 1988M IN NGC 4496B A. V. Filippenko, University of California at Berkeley; and W. L. W. Sargent, California Institute of Technology, report the discovery of a probable type II supernova long past maximum brightness in NGC 4496B (R.A. = 12h29.1m, Decl. = +04D12'.1, equinox 1950.0). The object was discovered serendipitously in a long-slit spectrum (p.a. 180D, range 620-686 nm, resolution 0.2-0.3 nm) obtained on Apr. 7 with a CCD spectrograph attached to the 5-m reflector at Palomar Observatory. Weak, broad (FWZI approx. 6000 km/s) H-alpha emission at the approximate redshift of NGC 4496B (cz = 4510 km/s) was detected 12".5 south of the nucleus, between NGC 4496B and an H II region in the foreground galaxy NGC 4496A (cz = 1700 km/s). No evidence for the SN was visible in a spectrum covering the range 422-510 nm (resolution 0.5 nm). If the distance to NGC 4496B is 60 Mpc (Ho = 75 km s**-1 Mpc**-1), the measured luminosity of H-alpha is 1.7 x 10**39 ergs/s. Comparison with the luminosity of SN 1980K (Uomoto and Kirshner 1986, Ap.J. 308, 685) suggests that SN 1988M was discovered 300-400 days past maximum, consistent with its spectroscopic appearance. Observers are urged to search for SN 1988M, which may have been as bright as mag 16-17, on images of NGC 4496B obtained during the past two years. PERIODIC COMET KOHOUTEK (1986k) Total visual magnitude estimates: Feb. 9.24 UT, 13.2 (A. Hale, Las Cruces, NM, 0.41-m reflector); 13.22, 13.0 (C. S. Morris, Whitaker Peak, CA, 0.26-m reflector); 16.21, 13.0 (Morris); 17.24, 13.2 (Hale); 18.30, 12.6 (R. Keen, Mt. Thorodin, CO, 0.32-m reflector). 1988 May 10 (4591) Brian G. Marsden
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