Circular No. 6910
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)


GRB 980519
     J. M. Muller, BeppoSAX Science Data Center, Rome, and Space
Research Organization of the Netherlands (SRON), Utrecht; J. Heise,
SRON; C. Butler, Agenzia Spaziale Italiana, Rome; F. Frontera,
Istituto Tecnologie e Studio Radiazioni Extraterrestri (ITESRE),
Bologna; L. Di Ciolo, G. Gandolfi and A. Coletta, BeppoSAX Science
Operation Center, Telespazio, Rome; and P. Soffitta, Istituto
Astrofisica Spaziale (IAS), CNR, Frascati, communicate on behalf of
the BeppoSAX team: "On May 19.51410 UT, a gamma-ray burst (Bacodine
trigger 6764) was detected by the Gamma-Ray Burst Monitor onboard
BeppoSAX.  A preliminary analysis shows a complex burst lasting 30
s with a peak intensity of about 1500 counts/s (40-700 keV).  An
x-ray counterpart of this burst was detected by the Wide Field
Camera WFC2 having a duration of 190 s and a peak flux of about 2.5
Crab (2-28 keV).  The position derived from the WFC2 image is R.A. =
23h22m15s, Decl. = +77o15'.0 (equinox 2000.0; error radius 3').  A
BeppoSAX follow-up observation is in progress."


GRB 980515
     R. Ricci and G. D'Andreta, BeppoSAX Science Operation Center,
Rome; E. Costa and P. Soffitta, IAS; J. in 't Zand, SRON; J. M.
Muller, BeppoSAX Science Data Center and SRON; L. Nicastro,
Istituto di Fisica Cosmica ed Applicazioni dell'Informatica, CNR,
Palermo; and E. Palazzi, ITESRE, report:  "The position of GRB
980515, observed by the BeppoSAX Gamma-Ray Burst Monitor and Wide
Field Camera (WFC, unit 2) on May 15.708495 UT, has been refined by
off-line data analysis.  The final position is R.A. = 21h17m25s,
Decl. = -67o15'.3 (equinox 2000.0), with an error radius of 4'.
The event duration was about 15 s in gamma-rays (in the energy band
40-700 keV), with a peak intensity of 450 counts/s.  The peak
intensity in the WFC (in the energy band 2-28 keV) was about 1.5
Crab.  The source 1SAX J2116.8-6712 (IAUC 6909) is therefore
positionally consistent with GRB 980515."


COMET C/1998 J1 (SOHO)
     R. H. McNaught, Bugaldie, N.S.W., reports that a photograph
taken on May 19.36 UT with a 55-mm f/1.4 camera lens and HP5 film
reveals a gas tail 10 deg long in p.a. 60 deg and a dust tail just
over 1 deg long in p.a. 80 deg.  At the same time, McNaught viewed
the comet via naked eye (m_1 about 4).

                      (C) Copyright 1998 CBAT
1998 May 20                    (6910)            Daniel W. E. Green