TITLE:   GCN CIRCULAR
NUMBER:  37537
SUBJECT: GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
DATE:    24/09/17 18:31:44 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.

The Fermi GBM team reported the detection of a burst at 2024-08-25T15:53:00 UTC triggered by Fermi Gamma-ray Burst Monitor (GBM) in GCN 37273. 

Follow up observations were reported in Gupta et al., GCN 37274; Di Lalla et al., GCN 37288; Evans et al., GCN 37290; Gropp et al., GCN 37294; Kuin et al., GCN 37296; Joshi et al., GCN 37298; Sharma et al., GCN 37301; Frederiks et al., GCN 37302; Chen-Wei et al., GCN 37315; Moss et al., GCN 37355; Leonini et al., GCN 37400; Paek al., GCN 37454; Ruffini et al., GCN 37536.

We analyzed the INTEGRAL SPI ACS data around the T0 given in GCN 37273 and detected a peak in the count rate which lasts for about 7 s. The SPI ACS is sensitive above 80 keV; the peak of the burst is at ~35000 counts/s and the steady rate preceding the event is around 3490 counts/s. The peak count rate may be affected by the instruments orientation with respect to the direction of the source. The light curve and the profile is given in the link below :

[GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE](https://docs.google.com/document/d/1de6UrFnIK8YoT4n61gwn11wn92oo9HlvxaronrH8RAk/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.