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IAUC 6774: X1354-644 = GS 1354-64; PKS 2155-304; 1997ds

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                                                 Circular No. 6774
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)


X1354-644 = GS 1354-64
     B. A. Harmon and C. R. Robinson, Marshall Space Flight Center,
NASA, report for the BATSE/Compton Observatory Science Team:  "This
x-ray transient (cf. IAUC 6772; Kitamoto et al. 1990, Ap.J. 361,
590) is being detected in hard x-rays with emission up to 200 keV
-- the outburst being first visible to BATSE around Oct. 29 at a
level of 60 mCrab (20-100 keV), where it remained until Nov. 7.
More recent data indicate that the source intensity (Nov. 12-18)
has increased to 160 mCrab, considerably higher than the reported
2-10-keV flux from RXTE (IAUC 6772).  Its location is consistent
with Ginga source GS 1354-64, Cen X-2, and MX 1353-64.  Evolution
from a hard spectrum (power-law index -2.1 to -2.3) to a softer one
(index -2.7) occurred between early November and Nov. 18, possibly
with a cutoff above 100 keV."


PKS 2155-304
     P. Sreekumar, Goddard Space Flight Center; and W. T. Vestrand,
University of New Hampshire, on behalf of the PKS 2155-304
multiwavelength campaign, report:  "Quick-look analysis of data
taken during Nov. 11-17 by the Energetic Gamma Ray Experiment
Telescope aboard the Compton Gamma Ray Observatory indicates that
this variable gamma-ray blazar is currently displaying an outburst
of gamma-ray emission; the current flux > 100 MeV is roughly a
factor of three greater than the highest flux previously seen in
PKS 2155-304.  Multiwavelength observations of PKS 2155-304 are
urged by southern-hemisphere observers during the outburst.
Additional gamma-ray observations are scheduled for Nov. 18-24
and Dec. 30-Jan. 13."


SUPERNOVA 1997ds IN MCG -01-57-007
     F. Patat and H. Boehnhardt, European Southern Observatory; and
X. Delfosse, Geneva Observatory, report that a preliminary
reduction of a spectrogram (range 350-890 nm, resolution 1.1 nm
FWHM) of SN 1997ds, obtained with the 1.54-m Danish telescope (+
DFOSC) on Nov. 20.01 UT at La Silla, shows H-alpha and H-beta lines
with well-developed P-Cyg profiles and expansion velocities
(deduced from the absorption minima, uncorrected for the galaxy
recession) of 9600 and 7500 km/s, respectively.  The Na I 589.2-nm
line has a marked P-Cyg profile (expansion velocity 7400 km/s).
The emission peaks of H lines indicate a recession velocity of 1700
km/s for the parent galaxy.  The blue continuum and these other
features are consistent with a type-II classification, about 2
weeks past maximum light.

                      (C) Copyright 1997 CBAT
1997 November 20               (6774)            Daniel W. E. Green

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