Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 6401: 1996Z; C/1995 O1

The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).

Read IAUC 6400  SEARCH Read IAUC 6402

View IAUC 6401 in .dvi or .ps format.
IAUC number

                                                  Circular No. 6401
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
Phone 617-495-7244/7440/7444 (for emergency use only)

     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; and
S. 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)."

     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

Read IAUC 6400  SEARCH Read IAUC 6402

View IAUC 6401 in .dvi or .ps format.

Our Web policy. Index to the CBAT/MPC/ICQ pages.

Valid HTML 4.01!