Circular No. 7174
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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1SAX J0835.9+5118
     G. Gandolfi, A. Coletta, and D. Ricci, BeppoSAX Scientific
Operation Center, Telespazio, Rome; J. Heise and J. in't Zand,
Space Research Organization of the Netherlands, Utrecht; and L.
Piro, E. Costa, and M. Feroci, Istituto di Astrofisica Spaziale,
CNR, Rome, write: "On May 20.08539 UT a fast x-ray transient, which
we designate 1SAX J0835.9+5118, has been detected in BeppoSAX Wide
Field Camera unit 1 (2-28 keV).  The event lasted about 10 s, with
a peak flux of 1 Crab in the range 2-25 keV.  The burst shows two
peaks; in coincidence with the second, harder burst, the GRB
Monitor (40-700 keV) obtained a marginal detection (4-sigma signal)
corresponding to a flux of about 1.8 Crab.  The position is R.A. =
8h35m56s, Decl. = +51o18'.6 (equinox 2000.0), with an error radius
of 3'.  No catalogued source at any wavelength lies in the error
box.  Furthermore, no quiescent emission was found from this source
during 3 hr following the outburst, with an upper limit of 6 mCrab
(2-10 keV), and in a combination of 1996-1999 data, with an upper
limit of 0.6 mCrab.  The normalized flux differences F_1-F_2 and
F_2-F_3 (where F_1, F_2, and F_3 are the fluxes in the bands 20-26,
7-20, and 3-7 keV) are -0.62 and +0.05, respectively.  These values
are typically softer than GRBs and fall in the same range as type-I
x-ray bursters.  Follow-up observations are encouraged to
investigate the nature of this object."


COMET C/1998 T1 (LINEAR)
     Visual m_1 estimates:  1998 Nov. 19.80 UT, 13.8 (M. Lehky,
Hradec Kralove, Czech Republic, 0.42-m reflector); Dec. 17.79, 13.6
(R. J. Bouma, Groningen, The Netherlands, 0.25-m reflector); 1999
Jan. 12.76, 13.1 (K. Hornoch, Lelekovice, Czech Republic, 0.35-m
reflector); May 19.61, 11.5 (N. Biver, Oahu, HI, 0.26-m reflector).


COMET C/1999 H3 (LINEAR)
     Visual m_1 estimates:  May 5.88 UT, 13.8 (Hornoch); 9.89, 13.5
(Lehky); 16.07, 13.7 (J. Carvajal, Ciudad Real, Spain, 0.45-m
reflector); 17.92, 13.1 (M. Reszelski, Szamotuly, Poland, 0.25-m
reflector); 18.96, 13.3 (M. Meyer, Frauenstein, Germany, 0.25-m
reflector); 19.90, 13.6 (Lehky).

                      (C) Copyright 1999 CBAT
1999 May 20                    (7174)            Daniel W. E. Green