ATel #132; M. Revnivtsev (IKI, Moscow; MPA, Garching), M. Chernyakova (ISDC, Geneve), F. Capitanio (IAS, Rome), N. J. Westergaard (DSRI, Copenhagen), V. Shoenfelder (MPE, Garching), N. Gehrels(GSFC/NASA), C. Winkler (ESTEC, Noordwijk)
on 28 Mar 2003; 18:05 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: M. Revnivtsev (email@example.com)
Subjects: X-ray, Request for Observations, Binary, Black Hole, Transient
Referred to by ATel #: 133, 136, 137, 138, 139, 142, 180, 189, 198, 301, 1739
We report the discovery of a variable source
with the ISGRI detector of the IBIS instrument onboard ESA's INTEGRAL
satellite on March 21. The source position is R.A.=17h46.4m, Dec.=-32o13'
(equinox 2000, position uncertainty 2'). The source flux increased by a
factor of 3 from March 21 to March 26. Its flux averaged over March 24-26
is ~60 mCrab in the 15-40 keV energy range, 60 mCrab between 40-100 keV and 70
mCrab in the 100-200 keV energy range. In comparison with other
transients, the spectrum is rather hard suggesting that the source is
may be a black hole candidate. Observations in other bands are encouraged.