ATel #9387: Activity from SAX J1747.0-2853 and KS 1741-293 detected by INTEGRAL Galactic Bulge Monitoring

J. Chenevez*, E. Kuulkers, R. Wijnands, A. Bazzano, V. Beckmann, T. Bird, A. Bodaghee, M. Del Santo, M. Del Santo, A. Domingo, P. Jonker, P. Kretschmar, C. Markwardt, A. Paizis, K. Pottschmidt, C. Sánchez-Fernández

*Corresponding author for this work

Research output: Other contributionNet publication - Internet publicationResearch


A new season of observations has started for the INTEGRAL Galactic Bulge Monitoring Program (ATel #438; Kuulkers et al. 2007, A&A, 466, 595; see also: ). During the observation performed on August 17, 2016, between UTC 17:20 and 21:01, the neutron star low-mass X-ray binary (NS-LMXB) SAX J1747.0-2853 (aka 1A 1743-288) is detected by the twin JEM-X cameras with an effective exposure time of ∼15 ks. The highest pixels on the combined JEM-X1+2 significance mosaics between 3-10 keV and 10-25 keV reach 6 and 3 σ, respectively. The corresponding fluxes are measured at 8 +/-2 mCrab (3-10 keV) and 6 +/-4 mCrab (10-25 keV). The source does not appear in the 18-40 keV and 40-100 keV mosaics of the IBIS/ISGRI camera, and we estimate the 5-σ upper limits at 18 mCrab and 21 mCrab, respectively. We note that SAX J1747.0-2853 was already reported in outburst during a Chandra observation on May 17, 2016 (ATel #9115). It appears from the MAXI 2-20 keV light curve ( ) that the outburst has declined and stabilized at the current level since the end of June 2016. During the same observation, a typical type-I X-ray burst from the NS-LMXB KS 1741-293 was detected by JEM-X on MJD 57617.8233 (UTC 19:45:30 on August 17, 2016). The burst light curves reveal this event is likely a photospheric radius expansion burst. This source is also detected by ISGRI, and we measure the following average fluxes: 9 +/-2 mCrab (3-10 keV), 11.5 +/-4 mCrab (10-25 keV), 18 +/-2 mCrab (18-40 keV), and 19 +/-3 mCrab (40-100 keV). INTEGRAL will continue to monitor the Galactic Bulge (next time on August 21st) at a rough cadence of an observation every satellite revolution (2.7 days) until October 24th. Near-Real-Time data are publicly available from the ISDC ( ).
Original languageEnglish
Publication date19 Aug 2016
VolumeATel #9387
Number of pages1
Publication statusPublished - 19 Aug 2016
SeriesThe Astronomer's telegram


  • X-ray
  • Gamma Ray
  • Neutron Star
  • Transient
  • Variables

Cite this

Chenevez, J., Kuulkers, E., Wijnands, R., Bazzano, A., Beckmann, V., Bird, T., Bodaghee, A., Del Santo, M., Del Santo, M., Domingo, A., Jonker, P., Kretschmar, P., Markwardt, C., Paizis, A., Pottschmidt, K., & Sánchez-Fernández, C. (2016, Aug 19). ATel #9387: Activity from SAX J1747.0-2853 and KS 1741-293 detected by INTEGRAL Galactic Bulge Monitoring. The Astronomer's telegram