Circular No. 5517 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@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU) SUPERNOVAE 1992W, 1992X, 1992Y Jean Mueller reports her discovery of three supernovae on plates taken with the 1.2-m Oschin Telescope in the course of the second Palomar Sky Survey. SN 1992W was at mag about 18 on a red plate taken by J. D. Mendenhall and Mueller on Apr. 28; the supernova is located 24" west and 32" north of the center of MCG +08-23-096 (R.A. = 12h48m.0, Decl. = +48 22', equinox 1950.0). SN 1992X was also at mag about 18 on a red plate taken by C. Brewer and Mendenhall on May 2; the supernova is located 2" west and 7" south of the center of MCG +06-32-024 (R.A. = 14h22m09s, Decl. = +35 22'.0). W. Sargent and T. Small confirmed SNe 1992W and 1992X with spectrograms obtained May 9 at the Hale 5-m telescope (+ double spectrograph). SN 1992Y in NGC 3527 (R.A. = 11h04m.5, Decl. = +28 48') was at mag 18.5-19 on a blue plate taken May 2 by Brewer and Mendenhall. SN 1992Y is located 13" east and 6" south of the galaxy's nucleus; no image is present at this location on prints from the original Palomar Sky Survey. HV VIRGINIS K. H. Mantel, H. Barwig, and M. Patschke, Universitats- Sternwarte Munchen; H. Ritter, Max-Planck-Institut fur Astrophysik, Garching, report: "Simultaneous high-speed UBVRI photometry was performed during the new outburst of HV Vir (IAUC 5502, 5505) using our fiberlink multicolor photometer (MCCP) at the 0.8-m telescope on Mt. Wendelstein. On Apr. 24 and 26, two measuring sequences of 5.4 hr each were obtained with a time resolution of 2 s. Between the first and second observations, the V brightness of HV Vir decreased by 0.3 mag. On both nights, the light curves showed periodic light variations with a maximum amplitude of 0.06 mag in B. A periodic analysis revealed two periods at 80.6 and 83.3 min, which give rise to a beat phenomenon in the hump structure of the light curves. The periods differ by 3.4 percent, which is typical for dwarf novae in superoutburst. This makes HV Vir a new member of the SU UMa subclass of dwarf novae. Its probable orbital period of 80.6 +/- 0.1 min and the recurrence time of about 60 years between subsequent superoutbursts resemble the behaviour of WZ Sge." Corrigendum. On IAUC 5503, line 12, for range 760-720 nm, read range 460-720 nm, 1992 May 9 (5517) Daniel W. E. Green
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