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IAUC 5619: 1992ay; GRS 1915+105; FG Sge

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                                                  Circular No. 5619
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505

     J. Maza, University of Chile; and M. Hamuy, Cerro Tololo
Interamerican Observatory, report the discovery by R. Antezana (
University of Chile) of an apparent supernova located in a system of
two anonymous galaxies (R.A. = 4h28m50s.2, Decl. = -46 30'32",
equinox 1950.0).  Its position is 6" east and 6" north of the
southernmost galaxy.  The supernova, of mpg about 18.5, was found
on a 20-min unfiltered IIa-O plate taken by C. Muena (CTIO) with
the CTIO Curtis Schmidt telescope on Sept. 20.323 UT.  Confirmation
was made by X. Guo (Yale University) on CCD B and V images obtained
on Sept. 25.403 with the CTIO 0.9-m telescope.

GRS 1915+105
     B. A. Harmon, W. S. Paciesas, and G. J. Fishman, report for
the BATSE/Compton Observatory Team:  "GRS 1915+105, the hard x-ray
transient discovered by the Granat WATCH experiment (IAUC 5590),
has been observed by BATSE, at flux levels between 280 and 400
mCrab since Aug. 15 in the energy band 20-230 keV, and continues to
be in outburst.  A flux history derived for the given location
indicates the following levels:  June 16-24, 90 +/- 10 mCrab; July
10-16, 190 +/- 20 mCrab; July 17-Aug. 5, 280 +/- 30 mCrab.  Systematic
effects due to source confusion appear minimal in these time
intervals.  The source has remained at about 300 mCrab since mid-
August.  Power-law fits to the spectrum in the band 20-120 keV from
June to September indicate an evolution from spectral index -2.0
(June) to -2.8 (September).  The spectral characteristics and slow
rise to apparent maximum intensity are similar to that observed
during the 1991 outburst of the black-hole candidate GX 339-4 (IAUC
5327, 5352), but differ markedly from those of the other recent
transient GRO J0422+32 (IAUC 5580, 5584)."

     C. E. Woodward, J. Cole, and T. Hodge, University of Wyoming;
and R. D. Gehrz, University of Minnesota, write:  "We have started
to monitor the decline in the light curve of FG Sge (IAUC 5610) and
report the following infrared magnitudes, obtained on the 2.3-m
Wyoming Infrared Observatory telescope:  Sept. 17.22 UT (with
bolometer detector), M = 3.64 +/- 0.10, N = 2.91 +/- 0.16; Sept. 19.14
(with InSb detector), J = 8.69 +/- 0.12, H = 7.69 +/- 0.05, K =
6.26 +/- 0.05, L' = 4.08 +/- 0.01."

1992 September 26              (5619)            Daniel W. E. Green

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