Supernova 1992az in NGC 818

C. Pollas, Observatoire de la Cote d'Azur, reports his discovery of a supernova (mag about 18) in the spiral galaxy NGC 818 = UGC 1633. The new object is located at R.A. = 2h05m45s.04, Decl. = +38 32'10".0 (equinox 1950.0), which is 28".5 east and 16".2 south of the galaxy's center (end figures 42s.61, 26".2). The supernova was found on a Tech Pan film obtained by Pollas (assisted by J.-B. Emond) on Sept. 27.04 UT and confirmed on an R plate taken Sept. 28.08 (respective limiting magnitudes 21.5 and 19). Nothing is visible on the POSS prints to R about 19 and B about 20. A nearby star of mag about 15 has end figures 45s.58, 38".1. F. Michel and P. Prugniel obtained a CCD image on Sept. 29.06 UT with the 1.2-m Observatoire de Haute-Provence telescope, under non-photometric conditions, measuring V = 18.85 +/- 0.2. R. Kirshner and S. Gordon, Harvard-Smithsonian Center for Astrophysics, communicate: "Spectra obtained with the Multiple Mirror Telescope (+ Red Channel spectrograph, range 400-800 nm) show that this object is a type-II supernova, with a well-developed P- Cyg profile at H-alpha. It closely resembles other type-II supernovae at an age of about 1 month. This is a reasonable candidate for a distance determination by the Expanding Photosphere Method, and further observations (especially V, R, and I photometry) will be valuable."