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Circular No. 6807
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)
SUPERNOVAE
L. Germany reports, on behalf of the Mount Stromlo Abell
Cluster Supernova Search Team (cf. IAUC 6639), their discovery of
four apparent supernovae on V and R CCD images (limiting mag V =
21.5) taken by S. Chan at the Mount Stromlo 1.27-m telescope (+
Macho Camera):
SN Date UT R.A. (2000.0) Decl. V Offset
1997fb Dec. 31 5 01 14.60 -38 38 12.7 18.6 1".3 W, 0".4 N
1997fc Dec. 31 4 59 58.81 -38 55 04.3 20.5 4".9 E, 1".9 N
1997fd Dec. 28 3 41 15.65 -53 29 30.8 21.2 7".1 E, 1".3 S
1997fe Dec. 31 4 33 07.64 -61 26 19.3 19.5 5".7 E, 6".2 S
Confirmation images (limiting mag R = 21) for all four objects were
obtained by S. Sabine at the same telescope on 1998 Jan. 12.
Previous images not showing each supernova were taken on the
following dates (with galaxy cluster membership noted
parenthetically): 1997fb and 1997fc, Dec. 19 (Abell 3301); 1997fd,
Dec. 12 (Abell 3158); 1997fe, Nov. 7 (Abell 3266).
PKS 2255-282
D. Bertsch, Goddard Space Flight Center, NASA, on behalf of
the EGRET Collaboration, writes: "The EGRET instrument on the
Compton Gamma Ray Observatory (CGRO) has detected a gamma-ray
source at energies above 100 MeV (significance 6 sigma) located at
R.A. = 22h55m, Decl. = -28o.2 (equinox 2000.0). The source's 50-
percent uncertainty contour includes PKS 2255-282, a flat-spectrum
radio quasar of visual mag 16.7 and redshift 0.9, and which has
catalogued radio fluxes of 1.8 Jy at 5 GHz and 3 Jy at 31 GHz. A
preliminary analysis indicates that the photon intensity is 3-4 x
10E-6 photons cmE-2 sE-1, integrated above 100 MeV (from data
obtained between 1997 Dec. 30 and 1998 Jan. 3). EGRET had not
detected this source previously, so that a strong flare is
indicated. The data will be released to the public archive at the
CGRO Science Support Center, as soon as initial processing is
completed. A preliminary view of the likelihood map is available
at the Web site http://cossc.gsfc.nasa.gov/cossc/2255_282.gif."
GRB 971227
Further to their item on IAUC 6803, S. A. Ilovaisky reports
that the CCD image of the GRB 971227 field noted therein can be
found at URL http://www.obs-hp.fr/~ilovaisky/grb.html.
(C) Copyright 1998 CBAT
1998 January 15 (6807) Daniel W. E. Green
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