Earlier activity from XTE J1739-302/IGR J17391-3021 detected by INTEGRAL
J. Chenevez (DTU/NSI, Denmark),  V. Beckmann (ISDC, Switzerland), E. Kuulkers (ESA/ESAC, Spain), A. Bird (Southampton, UK), S. Brandt (DTU/NSI, Denmark), T. J.-L. Courvoisier (ISDC, Switzerland), A. Domingo (LAEFF/INTA, Spain), K. Ebisawa (ISAS, Japan), P. Jonker (SRON, The Netherlands), P. Kretschmar (ESA/ESAC, Spain), C. Markwardt (GSFC, USA), T. Oosterbroek (ESA/ESTEC, The Netherlands), A. Paizis (INAF-IASF, Italy), D. Risquez (LAEFF/INTA, Spain), C. Sanchez-Fernandez (ESA/ESAC, Spain), S. Shaw (Southampton, UK/ ISDC, Switzerland), R. Wijnands (UvA, The Netherlands)
The recently reported outburst from the supergiant fast X-ray transient XTE J1739-302/IGR J17391-3021 (ATEL #1466) began already about five hours earlier than the Swift/BAT trigger on 2008-04-08.

The INTEGRAL/JEM-X monitor detected a flare starting at 16:18 (UTC) on the same day during recent Galactic Bulge monitoring observations (see ATEL #1385 and #1468). The flux averaged over the ~2 hour flare reached 42+/-8 mCrab (3-10 keV) and 80+/-15 mCrab (10-25 keV) with upper limits previous to the flare of 4 mCrab (3-10) keV and 8 mCrab (10-25 keV).

The source was also detected with INTEGRAL/IBIS/ISGRI with fluxes of 31+-1.7 mCrab (20-40 keV) and 13+-2.7 mCrab (40-80 keV) on 2008-04-08T14:01 during a 8 ksec exposure.
x-ray,gamma ray,binary,transient