Central Bureau for Astronomical Telegrams
IAUC 6436: GRO J1655-40 AND GRS 1915+105; 1985T; C/1995 O1
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Circular No. 6436
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
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)
Phone 617-495-7244/7440/7444 (for emergency use only)
GRO J1655-40 AND GRS 1915+105
B. A. Harmon, C. A. Wilson, M. McCollough, S. N. Zhang, W. S.
Paciesas, and C. R. Robinson report for the BATSE Compton
Observatory Science Team: "The two superluminal jet sources GRO
J1655-40 and GRS 1915+105 are both being detected strongly in hard
x-rays by BATSE. GRO J1655-40 was first detected in late May 1996,
but has gradually increased in brightness to an average around 0.6
Crab (20-100 keV) beginning about July 1. Occasional daily
averages reach 0.9 Crab. The spectrum is similar to that of
previous outbursts, exhibiting a power law shape to 200 keV with
photon indices of -2.3 to -2.6. GRS 1915+105 has also become
active again in hard x-rays, and is undergoing a moderately bright
outburst (about 200 mCrab in the band 20-100 keV) which began
around July 4. This precedes the increased radio flux by about 5
days (IAUC 6432). Recent increases in hard x-ray flux (around
June 21 and July 4 onward) have been accompanied by spectral
softening. The spectrum, adequately fit by a power law, has a
spectral index varying between -2.4 and -3.4."
SUPERNOVA 1985T IN ANONYMOUS GALAXY
R. H. McNaught, Anglo-Australian Observatory, reports his
discovery of an apparent supernova on a J plate taken by F. G.
Watson on 1985 June 15 with the U.K. Schmidt telescope, confirmed
on an R/I plate pair taken with the same telescope by M. R. S.
Hawkins on 1985 June 26. The R plates show the supernova at the
same brightness (mag about 18) on both dates; SN 1985T is slightly
fainter in I than R, relative to nearby stars. The position of SN
1985T is R.A. = 19h03m28s.54, Decl. = -65o36'12".4 (equinox 2000.0),
which is 22" east and 21" north of the galaxy's center. No star
appears to mag 21 at this position on U.K. Schmidt J plates taken
on 1975 June 14 and 1986 Sept. 3, or on R plates taken in
1995/1996; likewise, SN 1985T does not appear on the ESO R
(exposure number 5665) or ESO B (number 545) surveys.
COMET C/1995 O1 (HALE-BOPP)
Total visual magnitude estimates: June 24.58 UT, 5.6 (D.
Seargent, The Entrance, N.S.W., naked eye); July 8.91, 5.6 (J. D.
Shanklin, Versailles, France, 7x50 binoculars); 12.15, 5.7 (J. E.
Bortle, Stormville, NY, 10x50 binoculars); 14.28, 5.9 (C. S.
Morris, Lockwood Valley, CA, 10x50 binoculars); 15.22, 5.5 (R.
Keen, Mt. Thorodin, CO, 3x30 binoculars).
(C) Copyright 1996 CBAT
1996 July 16 (6436) Daniel W. E. Green
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