H. Kosai, National Astronomical Observatory of Japan, communicates 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 supernova 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 stellar object, located 57" south and < 2" east of the galaxy's center, that was not present in earlier images of the galaxy.
International Astronomical Union Circular
- Pub Date:
- December 1991