TITLE: GCN CIRCULAR NUMBER: 33437 SUBJECT: GRB 230307A: AstroSat LAXPC detection DATE: 23/03/09 13:15:29 GMT FROM: Tilak Katoch at TIFR Tilak Katoch, H. M. Antia and Parag Shah TIFR, Mumbai, India. Analysis of AstroSat LAXPC data showed the clear detection of a long GRB 230307A. The lightcurve shows the multiple burst profile with the peak triggered at T0 = 15h 44m 03s UT on 07 Mar 2023. The satellite was in a normal operating mode and well before the entry into the SAA region. The lightcurve has a burst profile with T90 = 36 sec. The strongest peak measured have a count rate above the background with 13321 +/- 117 count/sec in LAXPC10 and 4415 +/- 68 count/sec in LAXPC20 at T0+7 sec. Both LAXPC instruments (LAXPC10 and LAXPC20) have registered this burst profile in the light curve. For LAXPC20, the nominal energy range is 3-100 keV, but due to the lower gain in LAXPC10 the energy range is about 30-400 keV. The background subtracted lightcurve with 1 sec time-bin is available at the website: https://www.tifr.res.in/~astrosat_laxpc/grb230307alc.jpg [1] LAXPC was built by TIFR in collaboration with the Indian Space Research Organisation. The Indian Space Research Organisation funded, managed and facilitated the project. Links: ------ [1] https://www.tifr.res.in/~astrosat_laxpc/grb230106lc.jpg