Circular No. 6768
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 1997dp IN NGC 969
L. Arnold, Observatoire de Haute-Provence, reports the
discovery of an apparent supernova by Denis Christen, Hesingue,
France, on unfiltered CCD images taken with a 0.3-m telescope on
Nov. 1.10 and 1.93 UT, at magnitudes 17.8 +/- 0.4 and 17.9 +/- 0.4,
respectively. The supernova is located at R.A. =
2h34m06s.48, Decl. = +32o56'13".4 (equinox 2000.0), which is 22"
west and 36" south of the center of NGC 969. The object is absent
from several photographic atlses, including the Digital Sky Survey.
The Nov. 1.10 image (the sum of four 3-min frames; limiting mag
about 20) is available at
G. M. Hurst, Basingstoke, England, reports that prediscovery images
of SN 1997dp (measured position end figures 06s.48, 13".8) were
recognized by M. Armstrong, Rolvenden, Kent, on a 'patrol master'
frame obtained on Sept. 10.1 (mag 16), as well as on frames taken
on Sept. 28 and Oct. 14 (mag about 17).
S. Jha, P. Challis, P. Garnavich, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that SN 1997dp is a
type-Ia supernova, about 6 weeks past maximum, based on a spectrum
taken by Jha and Challis at the Multiple Mirror Telescope on Nov.
4.2 UT. The spectral features of the supernova are consistent with
the de Vaucouleurs' catalogue recession velocity for NGC 969 of
Z. Abraham, Instituto Astronomico e Geofisico (IAG),
Universidade de Sao Paulo (USP); and A. Damineli, IAG/USP and Joint
Institute for Laboratory Astrophysics, Boulder, report the fading
of the 7-mm flux density of eta Car by a factor of three since its
maximum in 1995: "Our observations were made with the Itapetinga
radiotelescope in Brazil. The measured flux density was 3.6 +/-
0.3 Jy. The He I 1083.0-nm line is fading as predicted (Damineli
1996, Ap.J. 460, L49) by the 5.52-yr period. The high-excitation
lines are expected to fade completely around Dec. 10 through Jan. 20."
Total visual magnitude estimates by R. J. Bouma, Groningen,
The Netherlands (0.25-m reflector): Oct. 11.14 UT, 12.7; 28.11,
12.8; 31.16, 12.6; Nov. 4.17, 12.8.
(C) Copyright 1997 CBAT
1997 November 4 (6768) Daniel W. E. Green