Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 6642: 1997 J1; 1997br

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 6641 SEARCH Read IAUC 6643

View IAUC 6642 in .dvi or .ps format.
IAUC number 

                                                 Circular No. 6642
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/cfa/ps/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)


COMET 1997 J1
     Jean Mueller reports her discovery of a comet on a 40-min
IIIa-J exposure by J. D. Mendenhall and herself with the 1.2-m
Oschin Schmidt telescope in the course of the second Palomar Sky
Survey.  The object's trail is condensed, with a diffuse coma and a
hint of a tail to the southeast.  The discovery was confirmed on
another 40-min exposure two nights later.  The following positions
of the trail ends were measured by Mueller and reduced by G. V.
Williams:

     1997 UT             R.A. (2000) Decl.        m1
     May   3.23542   11 39 24.56   +75 42 45.5    14
           3.26319   11 39 08.45   +75 42 19.7
           5.27153   11 18 18.25   +75 01 22.0
           5.29931   11 18 04.26   +75 00 49.8


SUPERNOVA 1997br IN ESO 576-40
     W.-d. Li, Beijing Astronomical Observatory (BAO), reports for
the BAO Supernova Survey:  "SN 1997br in ESO 576-40 (also known as
ESO 576-G40) has been followed photometrically at the BAO with the
0.6-m reflector and spectroscopically with the 2.16-m telescope,
confirming that SN 1997br is a peculiar (unusally bright) type-Ia
object.  Our observations show that the supernova was on rise from
Apr. 10 to 24, reaching its maximum optical brightness at magnitude
R about 13.7 and declining thereafter; the slow brightening of SN
1997br (only 0.6 mag in 13 days) also suggests a photometric
evolution similar to that of SN 1991T.  The spectroscopic
observations obtained on Apr. 11, 12, 13, 14, 16, and 28 also show
an evolution similar to that of SN 1991T.  The spectra of SN 1997br
taken before its optical maximum show no conspicuous Si absorption,
with Fe lines dominating.  The data taken on Apr. 28 (about 4 days
past maximum), however, show a spectrum typical of normal type-Ia
supernovae; conspicuous and relatively strong Si absorption was
seen at 628 nm, and the spectrum is dominated by lines of S, Si,
Ca, and Mg.  The expansion velocity of the envelope is estimated to
be about 8300 km/s, as derived from the Si absorption line at 628
nm."

                      (C) Copyright 1997 CBAT
1997 May 5                     (6642)            Daniel W. E. Green

Read IAUC 6641 SEARCH Read IAUC 6643

View IAUC 6642 in .dvi or .ps format.

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

Valid HTML 4.01!