Circular No. 5456 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 1992H IN NGC 5377 William Wren, McDonald Observatory, reports his visual discovery of a supernova located about 57" east and 19" north of the nucleus of NGC 5377 (R.A. = 13h54m.3, Decl. = +47 29', equinox 1950.0). Nothing appears at this position on the Palomar Sky Survey. SN 1992H was near mv about 15.0 at discovery on Feb. 11.50 UT, and the brightness has remained near this level on Tech Pan photographs taken by Wren on Feb. 13.37, 13.40, 15.31, 16.33, 17.36, 17.39, 21.24, and 21.27. T. Iijima, M. Turatto, and E. Cappellaro, Asiago Observatory, report that a spectrogram (resolution about 1 nm) of SN 1992H was obtained with the 1.82-m telescope (+ Boller & Chivens spectrograph + CCD) on Feb. 21.07 UT. A preliminary inspection of the spectrum shows a blue continuum with broad H-alpha (FWHM about 25 nm) and no sign of P-Cyg absorption, resembling the type-II linear supernovae 1979C and 1980K when 2-3 weeks past maximum light. NOVA CYGNI 1992 G. Sonneborn and R. Polidan, Goddard Space Flight Center; and S. Starrfield, Arizona State University, report: "Low- and high- resolution ultraviolet spectra (range 120-335 nm; resolution 0.6 and 0.02 nm) of Nova Cyg 1992 were obtained with the International Ultraviolet Explorer (IUE) satellite during Feb. 20.9-21.1 UT. Mg II (280.0 nm) and Al III (185.8 nm) were detected in emission, with blueward absorption troughs extending to about -2800 km/s. The spectrum shortward of 170 nm is broken up by numerous absorption features characteristic of optically thick ejecta observed in the early outburst phase of other novae (e.g., OS And, N Pup 1991). Numerous interstellar lines are detected against the relatively smooth continuum longward of 170 nm. The visual magnitude during these observations was about 4.9, as measured with the IUE Fine Error Sensor." Further visual magnitude estimates (cf. IAUC 5455): Feb. 20.79 UT, 5.2 (T. Seki, Geisei, Japan); 20.983, 4.9 (J. E. Bortle, Stormville, NY); 21.41, 4.4 (J. A. DeYoung, Washington, DC); 21.415, 4.7 (Bortle); 21.74, 4.4 (B. H. Granslo, Blindern, Oslo, Norway); 21.78, 4.3 (G. Hurst, Basingstoke, England); 22.00, 4.4 (DeYoung). 1992 February 21 (5456) Daniel W. E. Green
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