TITLE: GCN CIRCULAR NUMBER: 37510 SUBJECT: EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE DATE: 24/09/14 18:37:22 GMT FROM: Devraj Pawar at R. J. College, Mumbai - 86, India <devrajdp@gmail.com> Devraj Pawar (R. J. College, Mumbai-86, India) on behalf of a collaboration studying transients. Li et al. (GCN 37492) reported X-ray transient EP240913a at 2024-09-13T11:39:33 UTC and Yin et al. (GCN 37493) reported the occurrence of bright gamma-ray transient in the Fermi/GBM data approximately 180 seconds after time of EP240913a. We analyzed the INTEGRAL SPI ACS data around the time of EP240913a given in GCN 37492 and detected a peak in the light curve after a lag of ~177 s. The SPI ACS is sensitive above 80 keV; the peak of the burst is at ~3630 counts/s and the steady rate preceding the event is around 3300 counts/s, this may be affected by the instruments orientation with respect to the direction of the source given in GCN 37507. The light curve indicating the peak with respect to EP240913a time and the profile is given in the link below. [https://docs.google.com/document/d/1VmCF7dktgNCYbGKSV8uegpFCkx11WIfES9D5Z9Ua7EE/edit?usp=sharing]() This work is based on observations with INTEGRAL, an ESA project with instruments and a science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), and with the participation of Russia and the USA. The SPI-ACS detector system has been provided by MPE Garching/Germany. View this GCN Circular online at https://gcn.nasa.gov/circulars/37510. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...