//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23879 SUBJECT: IPN Triangulation of GRB 190206A (short/extremely bright) DATE: 19/02/06 18:25:20 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova, and T. Cline on behalf of the Konus-Wind team, K. Hurley, on behalf of the IPN, and S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, report: The extremely bright, short-duration GRB 190206A has been detected by Konus-Wind and Swift (BAT), so far, at about 13759 s UT (03:49:19). The burst was outside the coded field of view of the BAT. We have triangulated it to two preliminary, 3 sigma error boxes whose coordinates are: Box 1: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 313.330 (20h 53m 19s) -30.510 (-30d 30' 35") Corners: 324.521 (21h 38m 05s) -35.854 (-35d 51' 16") 323.780 (21h 35m 07s) -36.074 (-36d 04' 27") 307.665 (20h 30m 40s) -23.586 (-23d 35' 08") 308.080 (20h 32m 19s) -23.489 (-23d 29' 22") --------------------------------------------- Box 2: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 357.837 (23h 51m 21s) -14.585 (-14d 35' 07") Corners: 354.375 (23h 37m 30s) -24.856 (-24d 51' 20") 355.013 (23h 40m 03s) -24.585 (-24d 35' 08") 357.410 (23h 49m 38s) -6.031 ( -6d 01' 53") 357.048 (23h 48m 12s) -6.188 ( -6d 11' 16") --------------------------------------------- The error box area is about 7.4 sq. deg, and their maximum dimension is 19.05 deg (the minimum one is 23.2 arcmin). The Sun distances were about 13 (Box 1) and 34 deg (Box 2). This localization may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB190206_T13763/IPN/ The time history and spectrum will be given in forthcoming GCN Circulars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23880 SUBJECT: Konus-Wind observation of GRB 190206A DATE: 19/02/06 18:33:33 GMT FROM: Anna Kozlova at Ioffe Institute A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The extremely bright, short-duration, hard-spectrum GRB 190206A (IPN triangulation: Svinkin et al., GCN Circ. 23879) triggered Konus-Wind at T0=13763.926 s UT (03:49:23.926). The burst light curve shows a single smooth pulse which starts at ~T0 s and has a total duration of ~0.1 s. There is no evidence of an extended emission following the burst. The emission is seen up to ~10 MeV. As observed by Konus-Wind, the burst had a fluence of 1.64(-0.17,+0.17)x10^-5 erg/cm2, and a 16-ms peak flux, measured from T0+0.004 s, of 6.44(-0.75,+0.76)x10^-4 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+0.064 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.58(-0.10,+0.12) and Ep = 1600(-223,+248) keV (chi2 = 31/30 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.3 (chi2 = 30/29 dof). The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB190206_T13763/ The spectrum of the burst is typical of short-hard GRBs. Assuming the measured fluxes, GRB 190206A is the third-brightest short GRB detected by KW since November, 1994 in terms of peak flux, and among the dozen brightest short GRBs, in terms of the fluence (Svinkin et al. 2016, ApJS 224 10). Although the redshift of GRB 190206A is not available (yet), a comparison of the provisional track of the burst in the Ep,z-Eiso and Ep,z-Liso planes with the KW sample of GRBs with known redshifts (Tsvetkova et al., 2017, ApJ 850 161) suggests z < 0.5 (see http://www.ioffe.ru/LEA/GRBs/GRB190206_T13763/GRB190206A_z.pdf). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23892 SUBJECT: GRB 190206A: AstroSat CZTI detection DATE: 19/02/12 13:47:25 GMT FROM: Vidushi Sharma at IUCAA V. Sharma, D. Bhattacharya, T. Khanam and A. Vibhute (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 short bright GRB 190206A, which was also detected by Konus-Wind (Kozlova A. et al., GCN # 23880). The source was clearly detected in the 40-200 keV energy range. The light curve shows single pulse of emission with peak at 03:49:28.5 UT, about 4.6 s after the Konus-Wind trigger time, consistent with possible propagation delay. We do not see any activity around 03:49:19 UT, the reference time quoted by IPN (Svinkin D. et al., GCN # 23879). The measured peak count rate associated with the burst is 396 cts/s above the background in the combined data of four quadrants, with a total of 413 cts. The local mean background count rate was 515 cts/s. Using cumulative rates, we measure a T90 of 0.94 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.