//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20350 SUBJECT: GRB 170101B: Fermi GBM detection DATE: 17/01/01 10:24:47 GMT FROM: Andreas von Kienlin at MPE P Veres (UAH) and C Meegan (UAH) report on behalf of the Fermi GBM Team: "At 02:47:17.87 UT on 01 January 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170101B (trigger 504931642 / 170101116). The on-ground calculated location, using the GBM trigger data, is RA = 70.6, DEC = -1.6 (J2000 degrees, equivalent to 04 h 43 m, -1 d 35 '), with an uncertainty of 1.2 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). The angle from the Fermi LAT boresight at the GBM trigger time is 65 degrees. The GBM light curve shows/consists of two overlapping pulses with a duration (T90) of about 12.8 s (50-300 keV). The time-averaged spectrum from T0 to T0 + 15.7 s is best fit by a Band function with Epeak = 213 +/- 13 keV, alpha = -0.57 +/- 0.05, and beta = -2.29 +/- 0.12. The event fluence (10-1000 keV) in this time interval is (1.26 +/- 0.03)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0 + 6.1 s in the 10-1000 keV band is 7.0 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20351 SUBJECT: GRB 170101B: Astrosat CZTI detection DATE: 17/01/01 17:05:46 GMT FROM: Vedant Kumar at Astrosat/CZTI/IUCAA V. Kumar, D. Bhattacharya and V. Bhalerao (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed clear detection of GRB170101B (Fermi-GBM detection: Andreas von Kienlin et al., GCN 20350) in the 40-200 keV energy range. The light curve shows dual peak structure with stronger peak at 02:47:25.870 UT, 8 secs after the Fermi- GBM trigger(consistent with GCN 20350). The measured peak count rate is 209.80 counts/sec above the background in combined data of four quadrants, with a total of 1751 counts. The local mean background count rate was 377 counts/sec. Using cumulative rates, we measure a T90 of 14.3 sec. 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20360 SUBJECT: GRB 170101B: Lomonosov BDRG gamma ray discovery DATE: 17/01/03 12:10:03 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs N.L.Dzhioeva,V.V.Bogomolov, S.I.Svertilov, A.M.Amelushkin, V.O.Barinova, M.I.Panasyuk, A.V.Bogomolov, A.F.Iyudin, V.V.Kalegaev, D.Nguen, V.L. Petrov, I.V.Yashin, P.S.Kazarian Physics Department, Skobel`tsyn Institute of Nuclear Physics, Lomonosov Moscow State University V. Lipunov, E.S. Gorbovskoy, N.Tyurina, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute I. Park, J. Lee, S. Jeong Department of Physics, Sungkyunkwan University, Seobu-ro, Jangangu, Suwonsi, Korea A. J. Castro-Tirado Instituto de Astrofisica de Andalucia (IAA-CSIC) and Universidad de Malaga, Spain At 02:47:22 UT on 01 Jan 2017, the Lomonosov BDRG Gamma-ray Burst Monitor (http://lomonosov.sinp.msu.ru/en/scientific-equipment-2/bdrg), triggered GRB 170101B (P Veres (UAH), GCN 20350), total duration ~13s, the energy range 30-300 keV. LC is available at: https://downloader.sinp.msu.ru/static/grb_catalog/lc/grb_20170101_024722.png More information is available at: https://downloader.sinp.msu.ru/grb_catalog/ This Notice was ground-generated. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20361 SUBJECT: GRB 170101B: POLAR observation DATE: 17/01/03 15:05:07 GMT FROM: Yuanhao Wang at IHEP/CAS Hancheng Li (IHEP), Yuanhao Wang (IHEP), Zhengheng Li (IHEP) report on the behalf of the POLAR collaboration: At 2017-01-01T02:47:18.27 UT (T0), during a routine on-ground search of data, POLAR detected the GRB 170101B, which was also detected by the Fermi/GBM (trigger 504953918/170101374). The POLAR light curve consists of multiple peaks, with a duration (T90) of 11.2 s measured from T0+0.3 s. The 0.2-s peak rate measured from T0+8.1 s is 968 cnts/s, the total counts is about 5217 cnts. The above measurements are in the energy range of approximately 80-500 keV. LC_URL: http://polar.ihep.ac.cn/grb/2017/01/GRB170101B/lc/GRB170101B.JPG Using the best location from the Fermi/GBM, which is (J2000): RA: 70.640[deg] Dec: -1.580[deg] Err: 1.2[deg] the incident angle in POLAR coordinate at T0 is: theta: 63.43[deg] phi: -110.01[deg] The Minimum Detectable Polarization(MDP) for this burst is estimated to be ~23.5% [1-sigma, statistical only]. All analysis results presented above are preliminary. POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board the Chinese space laboratory Tiangong-2 launched on Sep 15, 2016. More information about POLAR can be found at:http://polar.ihep.ac.cn/en/, http://isdc.unige.ch/polar/and http://polar.psi.ch/html/. [GCN OPS NOTE(03jan17): Per operator, the SUBJECT-line was corrected from "170101A" to "170101B".]