Central Bureau for Astronomical Telegrams
IAUC 6812: 1998C; 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 6813
.dvi or
.ps format.
Circular No. 6812
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)
SUPERNOVA 1998C IN UGC 3825
Q. Y. Qiao, Y. L. Qiu, W. D. Li and J. Y. Hu, Beijing
Astronomical Observatory (BAO) report their discovery of a
supernova in UGC 3825 on unfiltered CCD images taken with 0.6-m
telescope on Jan. 21 UT. SN 1998C is located at R.A. = 7h23m34s.63,
Decl. = +41o26'04".2 (equinox 2000.0), which is 15".5 east and 0".5
south of the center of UGC 3825. CCD magnitudes: Jan. 21.57, 18.1;
22.59, 17.9. Unfiltered CCD images of the same field taken on Jan.
8 show no star at this position (limiting mag about 18.5). A low-
dispersion spectrum of the supernova taken on Jan. 22.70 by Qiao
and X. Y. Dong (BAO) and X. Zhang (Yunnan Astronomical Observatory)
with the BAO 2.16-m telescope at Xinglong Station shows this to be
a type-II supernova before maximum. The spectrum displays a blue
continuum with broad emission lines of H-alpha and H-beta
superimposed. The FWHM of H-alpha shows an expansion velocity of
8500 km/s. The recession velocity of UGC 3825 derived from the
narrow H-alpha emission line is 8600 km/s.
COMET C/1995 O1 (HALE-BOPP)
G. Garradd, Loomberah, N.S.W., reports that his CCD images
taken from the second half of 1997 Dec. through 1998 Jan. 17.46 UT
show an antitail, and the December images additionally show a
longer normal dust tail than previously; a Jan. 4 image can be
viewed at http://usrwww.mpx.com.au/~gjg/halebop.htm. On Jan. 6.70,
he found the antitail 1.5 deg long visually with a 0.25-m reflector,
much fainter than the main dust tail (which was seen to length 4.5
deg with 10x50 binoculars).
H. Boehnhardt, O. Hainaut, G. Pizarro, and R. West, European
Southern Observatory, write: "Schmidt telescope exposures of comet
C/1995 O1 taken between 1997 Dec. 29 and 1998 Jan. 6 at La Silla
show a straight tail about 10" wide that extends both 25' into the
sunward side of the nucleus at p.a. 8 deg and at least 4 deg to the
anti-solar side at p.a. 188 deg. This needle-like tail feature
partially overlaps with the normal diffuse dust tail northward of
the nucleus. The tail/antitail phenomenon is interpreted as due to
the presence of large and old dust grains in the cometary dust tail
that were released by the nucleus at least 100 days before the
observations (or even much earlier)."
Visual m_1 estimates (B = binoculars): Jan. 6.76 UT, 7.8 (A.
Pearce, Nedlands, W. Australia, 20x80 B); 17.06, 8.0 (R. Lourencon,
Jundiai, Brazil, 20x80 B); 21.4, 7.7 (S. O'Meara, Volcano, HI,
10x50 B).
(C) Copyright 1998 CBAT
1998 January 23 (6812) Daniel W. E. Green
Read IAUC 6813
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
