IAUC 6401
Circular No. 6401
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)
SUPERNOVA 1996Z IN NGC 2935
W. Johnson, Anza, CA, reports his discovery of a supernova (mag
about 16) on a CCD image taken on May 16.17 UT, SN 1996Z located
about 1' south of the center of NGC 2935 (R.A. = 9h36m.7,Decl. = -
21o08', equinox 2000). S. Benetti and M. Turatto, European
Southern Observatory; andS. Moehler, Space Telescope Science
Institute, report: "Inspection of a reduced CCD spectrogram (range
332-924 nm, resolution 2.7 nm) obtained on May 17.97 UT with the
ESO/MPI 2.2-m telescope (+ EFOSC2) confirms that this object is a
type-Ia supernova. The supernova, as measured on an R CCD frame, is
located 4" east and 71" south of the galaxy nucleus. The spectrum is
dominated by P-Cyg lines of intermediate-mass elements (mostly Ca II
H and K and infrared triplet; Si II; and S II) superimposed on a
relatively blue continuum, which is typical for a type-Ia supernova
about 5 days after maximum light. The expansion velocity deduced
from the minimum of Si II (635.5 nm), corrected by the redshift (2500
km/s, as measured from a strong Na I D interstellar absorption) of the
parent galaxy, is about 12 000 km/s. The mean expansion velocity
derived from the Ca II lines is about 16 200 km/s; this is substantially
faster than was seen in the prototype-Ia SN 1994D (Patat et al. 1996,
MNRAS 278, 111)." P. Garnavich, A. Riess, and R. Kirshner,
Harvard-Smithsonian Center for Astrophysics, communicate: "CCD
images of NGC 2935 were obtained by R. Jansen on May 18.1 UT
using the Whipple Observatory's 1.2-m telescope. The supernova (V
about 14.3) is 70" south of the galaxy's nucleus. A spectrum taken by
E. Barton with the 1.5-m Tillinghast telescope on May 18.2 shows that
the supernova is of type Ia, a week to ten days past maximum. Strong
interstellar Na I (589.3 nm) absorption is detected from our galaxy
(equivalent width 0.09 nm) and the host galaxy (equivalent width 0.14 nm)."
COMET C/1995 O1 (HALE-BOPP)
Total visual magnitude and coma-diameter estimates (cf. IAUC
6380): Apr. 14.67 UT, 7.4, about 9' (D. Seargent, The Entrance,
N.S.W., 10x50 binoculars); 18.05, 7.7, 6' (A. Baransky, Kiev, Ukraine,
0.11-m reflector); 21.48, 7.5, - (C. S. Morris, Pine Mountain Club, CA,
10x50 binoculars); 29.43, 7.8, 7' (R. Keen, Mt. Thorodin, CO, 0.15-m
reflector); May 15.58, 6.7, - (D. Seargent, The Entrance, N.S.W.,
2.5x25 binoculars); 16.42, 7.4, 11' (A. Hale, Cloudcroft, NM, 10x50
binoculars).
(C) Copyright 1996 CBAT
1996 May 18 (6401) Daniel W. E. Green
CBAT