//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25601 SUBJECT: GRB 190901A: Fermi GBM Final Real-time Localization DATE: 19/09/01 21:31:54 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 21:21:49 UT on 1 Sep 2019, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 190901A (trigger 589065714.612092 / 190901890). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 220.3, Dec = 0.9 (J2000 degrees, equivalent to J2000 14h 41m, 0d 54'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 85.0 degrees. The skymap can be found here: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190901890/quicklook/glg_skymap_all_bn190901890.png The HEALPix FITS file, including the estimated localization systematic, can be found here: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190901890/quicklook/glg_healpix_all_bn190901890.fit The GBM light curve can be found here: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190901890/quicklook/glg_lc_medres34_bn190901890.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25602 SUBJECT: GRB 190901A: BALROG localization (Fermi Trigger 589065714 / GRB 190901890) DATE: 19/09/01 21:51:54 GMT FROM: Jochen Greiner at MPE,Garching B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 589065714 at 21:21:49 on 01 Sept. 2019 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position (1 sigma statistical errors) is: RA(2000.0) = 224.7+/-0.8 deg Decl.(2000.0) = -0.5+/-1.1 deg We estimate an additional systematic error of 2 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB190901890/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB190901890/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB190901890/json //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25646 SUBJECT: GRB 190901A: Insight-HXMT/HE detection DATE: 19/09/04 06:48:31 GMT FROM: Ce Cai at IHEP J. M. Yao, Y. G. Zheng, C. Cai, Q. Luo, S. Xiao, Q. B. Yi, Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: At 2019-09-01T21:21:57.80 (T0), Insight-HXMT/HE detected GRB 190901A (trigger ID: HEB190901890) in a routine search of the data, which was also triggered by Fermi GBM (GCN #25601). The Insight-HXMT/HE light curve mainly consists of a single pulse with a duration (T90) of 15.69 s measured from T0-3.00 s. The 1-ms peak rate, measured from T0+0.95 s, is 1500 cnts/sec. The total counts from this burst is 12538 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB190901890_lc.jpg All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://www.hxmt.org. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25687 SUBJECT: GRB 190901A: AstroSat CZTI detection DATE: 19/09/09 11:17:45 GMT FROM: Ramkrishna Gaikwad at IUCAA/AstroSat R. Gaikwad, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed the detection of a GRB 190901A, which was also detected by Fermi GBM Final Real-time Localization (GCN #25601), BALROG localization (Biltzinger B. et al., GCN #25602), Global MASTER-Net (Lipunov V. et al., GCN #25603), Insight-HXMT/HE (Yao J. M. et al., GCN # 25646). The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple pulses of emission with the strongest peak at 2019-09-01 21:21:49.0 UT. The measured peak count rate associated with the burst is 215 cts/s above the background in the combined data of four quadrants, with a total of 891 cts. The local mean background count rate was 572 cts/s. Using cumulative rates, we measure a T90 of 13.4 s. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.