//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24775 SUBJECT: GRB 190610A: Swift detection of a short burst DATE: 19/06/10 11:51:39 GMT FROM: David Palmer at LANL P. A. Evans (U Leicester), J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU), M. J. Moss (GWU), D. M. Palmer (LANL), B. Sbarufatti (PSU), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 11:27:45 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190610A (trigger=907754). Swift did not slew to the burst location due to an observing constraint. The BAT on-board calculated location is RA, Dec 46.289, -7.666 which is RA(J2000) = 03h 05m 09s Dec(J2000) = -07d 39' 57" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 1 sec. This is superimposed on a rising background rate due to the approach of the SAA. The peak count rate was ~10,000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 10:44 UT on 2019 June 14. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24782 SUBJECT: GRB 190610A: Insight-HXMT/HE detection DATE: 19/06/11 10:47:53 GMT FROM: Ce Cai at IHEP C. Cai, S. Xiao, Q. Luo, Q. B. Yi, C. K. Li, X. B. Li, G. Li, J. Y. Liao, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, X. F. Lu, A. M. Zhang, Y. F. Zhang, 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 2019-06-10T11:27:45.00 (T0), Insight-HXMT/HE detected GRB 190610A (trigger ID: HEB190610477) in a routine search of the data, which was also triggered by Swift/BAT (GCN #24775). The Insight-HXMT/HE light curve mainly consists of a single pulse with a duration (T90) of 0.56 s measured from T0+0.96 s. The 1-ms peak rate, measured from T0+1.04 s, is 22407 cnts/sec. The total counts from this burst is 8510 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB190610477_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: 24783 SUBJECT: GRB 190610A: Swift-BAT refined analysis DATE: 19/06/11 14:09:44 GMT FROM: Amy Lien at GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), P. A. Evans (U Leicester), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+35 sec from the recent telemetry downlink, we report further analysis of BAT GRB 190610A (trigger #907754) (Evans et al., GCN Circ. 24775). The BAT ground-calculated position is RA, Dec = 46.244, -7.661 deg which is RA(J2000) = 03h 04m 58.6s Dec(J2000) = -07d 39' 38.7" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a short spike that starts ~T+0.2, peaks at ~T+0.3, and ends ~T+0.9. Due to the SAA, data beyond ~T+35 s are unavailable. T90 (15-350 keV) is 0.62 +- 0.11 sec (estimated error including systematics). The time-averaged spectrum from T+0.21 to T+0.89 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.32 +- 0.27. The fluence in the 15-150 keV band is 4.1 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.05 sec in the 15-150 keV band is 3.9 +- 0.5 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/907754/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24805 SUBJECT: GRB 190610A: CALET Gamma-Ray Burst Monitor detection DATE: 19/06/13 10:21:46 GMT FROM: Valentin Pal'shin at AGU T. Tamura (Kanagawa U), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita(AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The short GRB 190610A (Swift-BAT trigger #907754: Evans et al., GCN Circ. 24775, Palmer et al., GCN Circ. 24783; Insight-HXMT/HE detection: Cai et al., GCN Circ. 24782) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 11:27:45.359 UTC on 10 June 2019. The burst signal was seen by all CGBM detectors. The burst light curve shows a single pulse which starts at T+0.58 sec, peaks at T+0.83 sec and ends at T+1.41 sec. The T90 and T50 durations measured by the SGM data are 0.61 +- 0.16 sec and 0.26 +- 0.05 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1244201256/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24821 SUBJECT: GRB 190610A: Swift ToO observations DATE: 19/06/13 20:26:46 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 190610A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020896 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: 24828 SUBJECT: Konus-Wind observation of short/hard GRB 190610A DATE: 19/06/14 14:06:17 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, A. Kozlova, A.Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The short GRB 190610A (Swift-BAT detection: Evans et al., GCN 24775; Insight-HXMT/HE detection: Cai et al., GCN 24782) triggered Konus-Wind (KW) at T0=41263.560 s UT (11:27:43.560). The light curve of the burst shows a single, multi-peaked pulse with a total duration of ~0.6 s. The emission is seen up to ~10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB190610_T41263/ As observed by Konus-Wind, the burst had a fluence of (7.65 ± 1.48)x10^-6 erg/cm^2 and a 16-ms peak energy flux, measured from T0+0.080, of (2.43 ± 0.31)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The spectrum of the burst (measured from T0 to T0+0.256 s) is well fitted in the 20 keV - 20 MeV range by a cutoff power-law (CPL) function with the following model parameters: the photon index alpha = -0.28(-0.26,+0.33), and the peak energy Ep = 903(-181,+251) keV, chi2 = 53/47 dof. Fitting this spectrum with the GRB (Band) function yields nearly the same alpha and Ep, and an upper limit on beta of -2.3. All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24833 SUBJECT: GRB 190610A: Swift-XRT observations DATE: 19/06/14 15:34:31 GMT FROM: Aaron Tohuvavohu at PSU/Swift A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Swift/BAT-detected burst GRB 190610A (Palmer et al. GCN Circ. 24783), collecting 5.0 ks of Photon Counting (PC) mode data between T0+292.3 ks and T0+300.5 ks. One uncatalogued X-ray source has been detected consistent with being within 187 arcsec of the Swift/BAT position, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below: Source 7: RA (J2000.0): 46.2216 = 03:04:53.17 Dec (J2000.0): -7.6824 = -07:40:56.7 Error: 5.3 arcsec (radius, 90% conf. [Enhanced position]) Count-rate: (1.76 [+0.83, -0.64])e-3 ct s^-1 Distance: 111 arcsec from Swift/BAT position. Flux: (1.17 [+0.55, -0.42])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) We note that the position of this afterglow candidate is consistent with the galaxy SDSS J030452.77-074055.3 (r=21.5 AB), which has unknown redshift. Five uncatalogued sources were also detected too far from the GRB position to be likely afterglow candidates. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020896. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24834 SUBJECT: GRB 190610A: Swift/UVOT Upper Limits DATE: 19/06/14 17:08:39 GMT FROM: Paul Kuin at MSSL N.P.M. Kuin (UCL/MSSL) and P.A. Evans (Leicester U) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 190610A 292282 s after the BAT trigger (Evans et al., GCN Circ. 24775). No optical afterglow consistent with the BAT position or the XRT candidate position (Beardmore et al., GCN Circ. No. 24833) has been detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag v 292282 300459 4890 >20.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.09 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24898 SUBJECT: GRB 190610A: Further Swift-XRT observations DATE: 19/06/28 14:21:27 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has carried out further observations of GRB 190610A (Palmer et al. GCN Circ. 24783, Beardmore et al., GCN Circ. 24883), in order to ascertain whether the faint source in the BAT error circle ("Source 7") is fading. Marginal evidence of fading has been detected. In our later-epoch observations, the source is not detected at the 3-sigma level. The 3-sigma upper limit is 1.27 x 10^-3 ct/sec, or a 1-sigma confidence interval count-rate is 3.2 (+5.6, -1.7) x 10^-4 ct/sec (all rates are 0.3-10 keV). The original detection had a count rate of 1.76 (+0.83, -0.64) x 10^-3 ct/sec. Thus the source appears to be fading, but only at the 2.1-sigma level. Given the low significance of the fading, the faintness of the source, and the fact that low-level variability is not uncommon among X-ray sources, we cannot say with confidence that this is definitely the afterglow of GRB 190610A, however it remains a tantalising possibility. Due to the faint nature of the object, no further XRT observations are planned. The details of the source can be viewed, and the light curve rebinned, at: http://www.swift.ac.uk/ToO_GRBs/00020896/Source7.php This circular is an official product of the Swift-XRT team.