Circular No. 5400 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 1991bg IN NGC 4374 H. Kosai, National Astronomical Observatory of Japan, communi- cates the visual discovery by Reiki Kushida (Yatsugatake South Base Observatory), using a 0.40-m f/5 reflector, of a supernova in NGC 4374 (M84); on Dec. 9.844 UT, she estimated that the object is about 80" from the galaxy's center, in p.a. 165 deg, with mv = 14. Y. Kushida provides the following accurate position for the supernova, from photographs exposed Dec. 9.86 at the same site: R.A. = 12h22m31s.54, Decl. = +13 08'52".4 (equinox 1950.0). Approximate photovisual magnitudes from Y. Kushida: Nov. 17.802, [15.1; Dec. 3.777, 14.9; 9.860, 14.5; 10.804, 14.4. On Dec. 10.8, using the 0.91-m reflector (+ multichannel photometer) at the Dodaira Station of National Astronomical Observatory, T. Kato found that the super- nova was at V about 14.3. There is a foreground star of mag V = 14.7 some 80" from the galaxy's center toward the southwest. At the request of A. Filippenko (University of California at Berkeley), following his discussions with the Central Bureau, the Berkeley Automated Supernova Search Team obtained a CCD image of M84 on Dec. 12 UT; examination of the image by H. Newberg shows a stel- lar object, located 57" south and < 2" east of the galaxy's center, that was not present in earlier images of the galaxy. DY PERSEI A. Alksnis, Radioastrophysical Observatory, Latvian Academy of Sciences, reports: "This carbon star, suspected to be an R CrB-type variable, was observed with the Baldone Schmidt telescope and found to be in a deep minimum: Dec. 2.74 UT, V = 15.7; 5.54, V = 15.7; 5.55, B = 17.0. For a finding chart and information on previous photometric behavior, see Investig. Sun and Red Stars 33, 83 (1990, Riga)." PERIODIC COMET WIRTANEN (1991s) Total visual magnitude estimates (cf. IAUC 5389): Nov. 18.41 UT, 11.5 (J. E. Bortle, Stormville, NY, 0.32-m reflector); 18.52, 11.6 (A. Hale, Las Cruces, NM, 0.41-m reflector); Dec. 10.21, 13.9 (H. Mikuz, Ljubljana, Yugoslavia, 0.36-m reflector). 1991 December 12 Daniel W. E. Green