//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22325 SUBJECT: GRB 180113A: Swift detection of a burst DATE: 18/01/13 02:58:25 GMT FROM: David Palmer at LANL T. N. Ukwatta (LANL), J. R. Cummings (NASA/UMBC), A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 02:47:06 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180113A (trigger=804999). Due to an observing constraint, Swift could not slew to this burst. The BAT on-board calculated location is RA, Dec 19.215, +68.682 which is RA(J2000) = 01h 16m 52s Dec(J2000) = +68d 40' 55" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 20 sec. The peak count rate was ~9000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to an observing constraint, Swift will not be able to observe this location until at least T0+36 hours. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22328 SUBJECT: GRB 180113A: Fermi GBM observation DATE: 18/01/13 17:45:19 GMT FROM: Peter Veres at UAH P. Veres (UAH) reports on behalf of the Fermi GBM Team: "At 02:47:06.14 UT on 13 January 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 180113A (trigger 537504431 / 180113116). which was also detected by the Swift/BAT (Ukwatta et al., GCN 22325). The GBM on-ground location is consistent with the Swift position. The trigger resulted in an Autonomous Repoint Request (ARR) by the GBM Flight Software owing to the high peak flux of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight location. The initial angle from the Fermi LAT boresight to the best location is 51 degrees. The GBM light curve shows overlapping peaks with a duration (T90) of about 11 s (50-300 keV). The time-averaged spectrum from T0-1.4 s to T0+15.0 s is best fit by a Band function with Epeak = 247 +/- 12 keV, alpha = -0.59 +/- 0.04, and beta = -2.32 +/- 0.10. The event fluence (10-1000 keV) in this time interval is (1.007 +/- 0.012)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.45 s in the 10-1000 keV band is 9.3 +/- 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: 22329 SUBJECT: GRB 180113B: Fermi GBM detection DATE: 18/01/13 17:46:40 GMT FROM: Peter Veres at UAH P. Veres and C. Meegan (both UAH) report on behalf of the Fermi GBM Team: "At 00:16:00.47 UT on 13 January 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 180113B (trigger 537495365 / 180113011). The on-ground calculated location, using the GBM trigger data, is RA = 354.0, DEC = 13.5 (J2000 degrees, equivalent to 23 h 36 m, 13 d 28 '), 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 88 degrees. The GBM light curve consists of multiple pulses with a duration (T90) of about 15.9 s (50-300 keV). The time-averaged spectrum from T0-5.6 s to T0+17.0 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.95 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 670 +/- 41 keV. A Band function fits the spectrum equally well with Epeak = 647 +/- 46 keV, alpha = -0.95 +/- 0.02, and beta = -2.70 +/- 0.37. The event fluence (10-1000 keV) in this time interval is (1.539 +/- 0.017)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.2 s in the 10-1000 keV band is 36.9 +/- 0.5 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: 22330 SUBJECT: GRB 180113A: KAIT Optical Observations DATE: 18/01/13 18:22:57 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 180113A (Ukwatta et al., GCN 22325) starting at 03:57:49 UT, 70 minutes after the burst, and lasted for about 1.5 hours. Observations were performed with a sequence in the clear (roughly R), V, and I filters, and the exposure time was 60 s per image. The field is relative crowded, after a preliminay analysis using the subtraction method, we do not detect any optical afterglow candidate within the Swift-BAT error circle (Ukwatta et al., GCN 22325). The typical limiting magnitude of our single clear image is about 19.5 mag calibrated to the APASS catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22332 SUBJECT: GRB 180113A: Swift-BAT refined analysis DATE: 18/01/14 12:24:33 GMT FROM: Amy Lien at GSFC T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), (i.e. the Swift-BAT team): Using the data set from T-61 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 180113A (trigger #804999) (Ukwatta et al., GCN Circ. 22325). The BAT ground-calculated position is RA, Dec = 19.211, 68.682 deg which is RA(J2000) = 01h 16m 50.7s Dec(J2000) = +68d 40' 55.9" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 75%. The mask-weighted light curve shows some weak emissions that starts at ~T-15 s, followed by the main structure with several overlapping pulses from ~ T0 to ~T+15 s, and a weak tail that lasts until ~T+70 s. T90 (15-350 keV) is 64 +- 16 sec (estimated error including systematics). The time-averaged spectrum from T-12.98 to T+67.02 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.08 +- 0.06. The fluence in the 15-150 keV band is 4.8 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+10.52 sec in the 15-150 keV band is 2.5 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/804999/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22334 SUBJECT: GRB 180113C: Fermi GBM detection DATE: 18/01/14 14:09:26 GMT FROM: Peter Veres at UAH P. Veres (UAH), C. Meegan (UAH) and A. von Kienlin (MPE) report on behalf of the Fermi GBM Team: "At 10:02:05.41 UT on 13 January 2008, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 180113C (trigger 537530530 / 180113418). The on-ground calculated location, using the GBM trigger data, is RA = 174.6, DEC = -64.7 (J2000 degrees, equivalent to 11 h 39 m, -64 d 44 '), with an uncertainty of 1 degree (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 trigger resulted in an Autonomous Repoint Request (ARR) by the GBM Flight Software owing to the high peak flux of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight location. The initial angle from the Fermi LAT boresight to the GBM ground location is 63 degrees. The GBM light curve shows multiple overlapping pulses with a duration (T90) of about 24.6 s (50-300 keV). The time-averaged spectrum from T0+3.1 s to T0+34.8 s is best fit by a Band function with Epeak = 307 +/- 4 keV, alpha = -0.68 +/- 0.01, and beta = -2.09 +/- 0.01. The event fluence (10-1000 keV) in this time interval is (6.838 +/- 0.017)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+10. s in the 10-1000 keV band is 26.3 +/- 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: 22339 SUBJECT: GRB 180113A: Swift ToO observations DATE: 18/01/15 11:28:20 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Swift/BAT GRB 180113A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00804999 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Swift/BAT event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22342 SUBJECT: GRB 180113B: Insight-HXMT/HE observation DATE: 18/01/15 14:30:16 GMT FROM: Shaolin Xiong at IHEP C. K. Li, S. L. Xiong, X. B. Li, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, J. L. Zhao, 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, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),report on behalf of the Insight-HXMT team: At 2018-01-13T00:16:00.00 UT (T0), the Insight-HXMT/HE detected GRB 180113B(trigger ID: HEB180113011) in a routine search of the data, which was also triggered by Fermi/GBM (Veres et al. GCN 22329) and INTEGRAL/SPI-ACS. The Insight-HXMT light curve consists of multiple pulses with a duration (T90) of 11.7 s measured from T0+1.06 s. The 1-s peak rate, measured from T0+1.30 s, is 13236.7 cnts/sec. The total counts from this burst is 31306.5 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB180113011_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 (record 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. The analysis results presented above are preliminary; final results will be published elsewhere. 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/index.php/enhome . //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22343 SUBJECT: GRB 180113C: Insight-HXMT/HE observation DATE: 18/01/15 14:37:31 GMT FROM: Shaolin Xiong at IHEP C. K. Li, S. L. Xiong, X. B. Li, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, J. L. Zhao, 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, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: At 2018-01-13T10:02:07.50 UT (T0), the Insight-HXMT/HE detected GRB 180113C (trigger ID: HEB180113418) in a routine search of the data, which was also triggered by Fermi/GBM (Veres et al. GCN 22334) and INTEGRAL/SPI-ACS. The Insight-HXMT light curve consists of multiple pulses with a duration (T90) of 22.05 s measured from T0+4.17 s. The 1-s peak rate, measured from T0+7.85 s, is 21741.2 cnts/sec. The total counts from this burst is 235458.8 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB180113418_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 (record 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. The analysis results presented above are preliminary; final results will be published elsewhere. 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/index.php/enhome . //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22344 SUBJECT: Konus-Wind observation of GRB 180113A DATE: 18/01/15 15:37:30 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 180113A (Swift/BAT detection: Ukwatta et al., GCN 22325, GCN 22332; Fermi-GBM detection: Veres, GCN 22328) triggered Konus-Wind at T0=10027.005 s UT (02:47:07.005). The KW light curve shows a single pulse with a total duration of ~13 s. The emission is seen up to ~1 MeV. As observed by Konus-Wind, the burst had a fluence of (1.36 ± 0.10)x10^-5 erg/cm2 and a 64-ms peak energy flux, measured from T0+0.448, of (3.1 ± 0.3)x10^-6 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+16.640 s) is best fit in the 20 keV - 15 MeV range by a cutoff power-law (CPL) function with the following model parameters: the photon index alpha = -0.80(-0.12,+0.13), and the peak energy Ep = 293(-29,+36) keV, chi2 = 72/98 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-3.0. The spectrum near the peak count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by the CPL function with the following model parameters: the photon index alpha = -0.72(-0.12,+0.13), and the peak energy Ep = 308(-30,+36) keV, chi2 = 83/98 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-3.0. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180113_T10027/ All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22349 SUBJECT: IPN Triangulation of GRB 180113C DATE: 18/01/16 05:35:16 GMT FROM: Anna Kozlova at Ioffe Institute K. Hurley, on behalf of the IPN, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D.Svinkin, and T. Cline on behalf of the Konus-Wind team, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: The long-duration GRB 180113C (Fermi GBM detection: Veres et al., GCN 22334) was detected by Fermi(GBM), Konus-Wind, INTEGRAL(SPI-ACS), Mars-Odyssey (HEND), and Swift(BAT) at about 36125 s UT (10:02:05). The burst was outside the coded field of view of the BAT. We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 175.300 (11h 41m 12s) -63.261 (-63d 15' 40") Corners: 173.892 (11h 35m 34s) -62.126 (-62d 07' 33") 176.415 (11h 45m 40s) -64.502 (-64d 30' 07") 176.856 (11h 47m 26s) -64.371 (-64d 22' 16") 174.311 (11h 37m 15s) -62.002 (-62d 00' 07") --------------------------------------------- The error box area is 2174 sq. arcmin, and its maximum dimension is 2.67 deg (the minimum one is 13.8 arcmin). The Sun distance was 82 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB180113_T36129/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22351 SUBJECT: Konus-Wind observation of GRB 180113C DATE: 18/01/16 10:25:27 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 180113C (Fermi-GBM detection: Veres et al., GCN 22344; Insight-HXMT/HE observation: Li et al., GCN 22343; IPN Triangulation: Hurley et al., GCN 22349) triggered Konus-Wind at T0=36129.524 s UT (10:02:09.524) The burst light curve shows a bright, multi-peaked pulse with a total duration of ~80 s. The emission is seen up to ~10 MeV. As observed by Konus-Wind, the burst had a fluence of (2.9 ± 0.1)x10^-4 erg/cm2 and a 64-ms peak energy flux, measured from T0+6.400, of (3.1 ± 0.3)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+37.888 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.78 (-0.05,+0.05), the high energy photon index beta = -2.14 (-0.06,+0.05), the peak energy Ep = 368 (-22,+24) keV, chi2 = 108/96 dof. The spectrum near the peak count rate (measured from T0+6.400 s to T0+6.912 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.35 (-0.16,+0.20), the high energy photon index beta = -2.09 (-0.18,+0.13), the peak energy Ep = 429 (-76,+85) keV, chi2 = 59/63 dof. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB80113_T36129/ All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22354 SUBJECT: IPN Triangulation of GRB 180113B DATE: 18/01/16 15:03:48 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, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, and A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report: The bright long-duration GRB 180113B (Veres and Meegan, GCN Circ. 22329) was detected by Fermi (GBM trigger 537495365), Konus-Wind, and INTEGRAL (SPI-ACS) at about 960 s UT (00:16:00). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 6.697 (00h 26m 47s) +24.021 (+24d 01' 15") Corners: 3.866 (00h 15m 28s) +27.572 (+27d 34' 20") 8.260 (00h 33m 03s) +22.591 (+22d 35' 29") 7.772 (00h 31m 05s) +22.219 (+22d 13' 07") 3.373 (00h 13m 29s) +27.185 (+27d 11' 07") --------------------------------------------- The error box area is 3.7 sq. deg, and its maximum dimension is 6.4 deg (the minimum one is 35 arcmin). The Sun distance was 82 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB180113_T00958/IPN The Konus-Wind time history and spectrum will be given a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22355 SUBJECT: Konus-Wind observation of GRB 180113B DATE: 18/01/16 15:18:46 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 180113B (Fermi-GBM detection: Veres & Meegan, GCN 22329; Insight-HXMT/HE observation: Li et al., GCN 22342; IPN Triangulation: Svinkin et al., GCN 22354) triggered Konus-Wind at T0=958.621 s UT (00:15:58.621). The KW light curve shows a multiple pulses in the interval from ~T0 to ~T0+20 s. The emission is seen up to ~10 MeV. As observed by Konus-Wind, the burst had a fluence of (4.05 ± 0.29)x10^-5 erg/cm2 and a 64-ms peak energy flux, measured from T0+3.200 s, of (2.2 ± 0.1)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+20.224 s) is best fit in the 20 keV - 15 MeV range by a cutoff power-law (CPL) function with the following model parameters: the photon index alpha = -0.97(-0.07,+0.08), and the peak energy Ep = 559(-58,+71) keV, chi2 = 81/98 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-2.0. The spectrum near the peak count rate (measured from T0 to T0+3.840 s) is best fit in the 20 keV - 15 MeV range by the CPL function with the following model parameters: the photon index alpha = -0.80(-0.06,+0.06), and the peak energy Ep = 611(-47,+53) keV, chi2 = 93/98 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-2.0. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180113_T00958/ All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22359 SUBJECT: GRB 180113A CALET Gamma-Ray Burst Monitor detection DATE: 18/01/17 05:44:00 GMT FROM: Takanori Sakamoto at AGU S. Torii (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena) and the CALET collaboration: The long-duration GRB 180113A (Ukwatta et al., GCN circ. 22325; Veres et al., GCN circ. 22328; Frederiks et al., GCN circ. 22344) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 02:47:03.27 on 13 January 2018. The burst signal was seen by the all CGBM instruments. The light curve of the SGM shows two overlapping pulses. The emission starts at T+3 sec, peaks at T+4 sec and ends at T+16 sec. The T90 and the T50 durations measured by the SGM data are 11.3 +- 1.3 sec and 7.0 +- 0.6 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1199846617 The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22363 SUBJECT: GRB 180113A: AstroSat CZTI detection DATE: 18/01/20 18:19:33 GMT FROM: Vidushi Sharma at IUCAA V. Sharma (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), 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 bright GRB 180113A, which was also detected by Swift (Ukwatta T. N. et al., GCN 22325), Fermi-GBM (Veres P. et al., GCN 22328), Konus-Wind (Frederiks D. et al., GCN 22344) and CALET (Torii S. et al., GCN 22359). The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 02:47:07.500 UT, ~1.5 s after the Swift-BAT trigger. The measured peak count rate is 345 cts/s above the background in combined data of four quadrants, with a total of 2536 cts. The local mean background count rate was 628 cts/s. Using cumulative rates, we measure a T90 of 14.3 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22364 SUBJECT: GRB 180113B: AstroSat CZTI detection DATE: 18/01/20 18:21:39 GMT FROM: Vidushi Sharma at IUCAA 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 bright GRB 180113B, which was also detected by Fermi-GBM (Veres P. et al., GCN 22329), Insight-HXMT/HE (Li C. K. et al., GCN 22342), IPN Triangulation (Svinkin D. et al., GCN 22354) and Konus-Wind (Frederiks D. et al., GCN 22355). The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 00:16:01.500 UT, ~1 s after the Fermi-GBM trigger. The measured peak count rate is 1344.6 cts/s above the background in combined data of four quadrants, with a total of 3534 cts. The local mean background count rate was 520 cts/s. Using cumulative rates, we measure a T90 of 10.8 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.