October 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 40224] GRB 251006B: Insight-HXMT detection
by GCN Circulars 08 Oct '25

08 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42155 SUBJECT: GRB 251006B: Insight-HXMT detection DATE: 25/10/08 04:38:08 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> Chen-Wei Wang, Yue Wang, Cheng-Kui Li, Shao-Lin Xiong, and Chao Zheng report on behalf of the Insight-HXMT team: At 2025-10-06T20:05:04.350 (T0), Insight-HXMT/HE detected the burst GRB 251006B, which is also detected by Fermi/GBM (Fermi GBM team, GCN#42131), EP (Yin et al., GCN#42137) and SVOM/GRM (Wang et al., GCN#42139). The Insight-HXMT/HE light curve mainly consists of multi-pulses with a T90 of 4.6 +1.1/-0.8 s. The 1s peak rate, measured from T0-0.1 s, is 3694 cnts/sec. The total counts from this burst is 5990 counts. The HXMT/HE light curve can be found here: https://www.bursthub.cn//admin/static/hxmtgrb251006B.png All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 60-900 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/42155. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40223] GRB 251007A: SVOM/C-GFT optical observations
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42154 SUBJECT: GRB 251007A: SVOM/C-GFT optical observations DATE: 25/10/07 23:55:44 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Chao WU (NAOC), Zhe Kang (CHO), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC), Yulei Qiu(NAOC), Jing Wang (NAOC), Jinsong Deng(NAOC), Lei Huang(NAOC), Jianyan Wei (NAOC) report on behalf of the SVOM/C-GFT team: We observed the field of GRB 251007A detected by Swift/BAT (Ambrosi et al., GCN 42146) and Glowbug (Cheung et al., GCN 42151) with LATIOS on SVOM/C-GFT. Observations started at 2025-10-07T19:37:48 UTC, ~50 seconds after the trigger. The optical counterpart reported by Swift/UVOT (Ambrosi et al., GCN 42146) is clearly detected in our i-band images. The magnitude is : |[date-obs|mid-time] | Mid_t-T0(s) | exposure time (s) | band | mag (AB) | mag_err | |---------------------|-------------|-------------------|------|----------|---------| | 2025-10-07T19:37:53 | 55 | 10 | i | 16.41 | 0.13 | The photometry was calibrated against the UCAC4 catalogue, and no correction for Galactic dust extinction was applied. We thank the observation assistants Chunlei Guo and Shuai Liu at Jilin observatory for their excellent support. The Chinese Ground Follow-up Telescope (C-GFT) for the SVOM mission is located at Jilin Station, Changchun Observatory, National Astronomical Observatories, CAS. It features two instruments: (1) CATCH at the Cassegrain focus with a 21 arcsec x 21 arcsec FOV for simultaneous g/r/i-band imaging, and (2) LATIOS, a 4k x 4k CMOS camera at the prime focus with a 1.28 deg x 1.28 deg FOV that images in g, r, and i bands via filter switching. View this GCN Circular online at https://gcn.nasa.gov/circulars/42154. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40222] GRB 251005C: PRIME J-band upper limit
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42153 SUBJECT: GRB 251005C: PRIME J-band upper limit DATE: 25/10/07 23:04:57 GMT FROM: N. Passaleva at Sapienza University of Rome <niccolo.passaleva(a)uniroma1.it> M. El Kabir (U Rome), O. Guiffreda (UMD), N. Passaleva (U Rome), J. Durbak (UMD), E. Troja (U Rome), A. S. Kutyrev (NASA/GSFC), S. B. Cenko (NASA/GSFC) Following the Swift/BAT detection and Swift/XRT localization of an uncatalogued source (Page et al, GCN 42113), we observed the transient field in J filter with PRIME ~32.9 hours after the initial BAT trigger. Using Two Micron All Sky Survey (2MASS) for preliminary calibration we do not detect any uncatalogued source down to J>20.2 AB (3-sigma) not corrected for galactic extinction at the position of the candidates reported by Swift/XRT (Goad et al. GCN 42116), and SVOM/VT (Palmerio et al., GCN 42123). PRIME is a 1.8m telescope with 1.56 square degree FOV (0.5 arcsec/pixel) located in Sutherland, South Africa at the South African Astronomical Observatory (SAAO) (Kutyrev et al. 2023, Yama et al. 2023, Durbak et al. 2024). We thank the Osaka University observers at PRIME and the staff at SAAO for their support with these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/42153. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40221] Swift GRB 251007B: Global MASTER-Net observations report
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42152 SUBJECT: Swift GRB 251007B: Global MASTER-Net observations report DATE: 25/10/07 22:37:00 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 251007B ( A. Melandri et al., GCN 42147) errorbox 9413 sec after notice time and 9658 sec after trigger time at 2025-10-07 22:24:05 UT, with upper limit up to 17.1 mag. The observations began at zenith distance = 83 deg. The sun altitude is -52.3 deg. The galactic latitude b = -5 deg., longitude l = 222 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3009588 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 9688 | MASTER-SAAO | C | 60 | 17.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42152. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40220] GRB 251007A: Glowbug gamma-ray detection
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42151 SUBJECT: GRB 251007A: Glowbug gamma-ray detection DATE: 25/10/07 22:35:45 GMT FROM: C.C. Cheung at Naval Research Lab <Teddy.Cheung(a)nrl.navy.mil> C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report: The Glowbug gamma-ray telescope [1,2,3], operating on the International Space Station, reports the detection of GRB 251007A, which was also detected by Swift/BAT (GCN 42146) and CALET (Trigger 1443900615). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2025-10-07 19:37:09.088 with a duration of 65.5 s and a total significance of about 137.8 sigma. The Glowbug light curve is dominated by a triple-peaked structure spanning ~ T0+40s to +60s corresponding to the peak emission observed by Swift/BAT and CALET. Note the Glowbug onset time is ~11 s after the Swift/BAT trigger time (19:36:58). A search of the Glowbug data for emission at the Swift/BAT T0 was inconclusive. The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS. Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS, and operated until 2024 April when it was put in safe storage on orbit. Glowbug was recently removed from storage and resumed operation on 2025 September 12. [1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959 [2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O [3] Woolf, R.S. et al. 2024, Proc. SPIE, 13151, id. 1315108 Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42151. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40219] GRB 251007B: SVOM/C-GFT upper limit
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42150 SUBJECT: GRB 251007B: SVOM/C-GFT upper limit DATE: 25/10/07 22:19:37 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Chao WU (NAOC), Zhe Kang (CHO), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC), Yulei Qiu(NAOC), Jing Wang (NAOC), Jinsong Deng(NAOC), Lei Huang(NAOC), Jianyan Wei (NAOC), N. A. Webb (IRAP), O. Godet (IRAP) report on behalf of the SVOM/C-GFT team: We observed the field of GRB 251007B (SVOM burst-id sb25100703) detected by Swfit/BAT (Melandri et al. GCN 42147) and SVOM/ECLAIRs (Webb et al., GCN 42148) with LATIOS on SVOM/C-GFT. Observations started at 2025-10-07T19:44:29 UTC, ~83 seconds after the trigger. A series of g, r, and i band images were obtained. No credible candidate was detected within the error box provided by XRT (Melandri et al. GCN 42147) in our images after preliminary processing, the three sigma upper limits are: | Mid_t - T0 (s) | Exposure Time (s) | Band | Upper Limit (AB) | |----------------|-------------------|------|------------------| | 113 | 6×10 | i | 18.50 | | 248 | 18x10 | i | 18.90 | The photometry was calibrated with UCAC4 catalogue. Magnitudes were not corrected for dust extinction. We thank the observation assistants Chunlei Guo and Shuai Liu at Jilin observatory for their excellent support. The Chinese Ground Follow-up Telescope (C-GFT) for the SVOM mission is located at Jilin Station, Changchun Observatory, National Astronomical Observatories, CAS. It features two instruments: (1) CATCH at the Cassegrain focus with a 21 arcsec x 21 arcsec FOV for simultaneous g/r/i-band imaging, and (2) LATIOS, a 4k x 4k CMOS camera at the prime focus with a 1.28 deg x 1.28 deg FOV that images in g, r, and i bands via filter switching. View this GCN Circular online at https://gcn.nasa.gov/circulars/42150. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40218] Swift GRB 251007A: Global MASTER-Net observations report
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42149 SUBJECT: Swift GRB 251007A: Global MASTER-Net observations report DATE: 25/10/07 21:52:44 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB 251007A ( E. Ambrosi et al., GCN 42146) errorbox 7658 sec after notice time and 7679 sec after trigger time at 2025-10-07 21:44:57 UT, with upper limit up to 15.8 mag. The observations began at zenith distance = 84 deg. The sun altitude is -51.3 deg. The galactic latitude b = 32 deg., longitude l = 203 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3009554 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 7770 | MASTER-Kislovodsk | C | 180 | 15.8 | 7770 | MASTER-Kislovodsk | C | 180 | 14.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42149. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40217] GRB 251007B: SVOM detection of a faint burst
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42148 SUBJECT: GRB 251007B: SVOM detection of a faint burst DATE: 25/10/07 20:37:26 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> N. A. Webb, O. Godet, S. Guillot (IRAP), F. Lacreu (IAP) report on behalf of the SVOM mission team At 2025-10-07T19:43:23 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 251007B (SVOM burst-id sb25100703), also detected by Swift/BAT (GCN #42147, Melandri et al. 2025). The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network. The burst was detected both by the Count-Rate Trigger (CRT) and the Image Trigger (IMT), which produced a sequence of 7 alerts. CRT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 9.53 in the [8-50] keV energy band over a time window of 20.40 seconds starting at 2025-10-07T19:42:57. The localization of the best alert is R.A., Dec. 101.997, -10.279 degrees: R.A. (J2000) = 6h47m59.29s Dec. (J2000) = -10d16m42.81s with a 90% confidence level (C.L.) radius of 8.33 arcmin (including systematic error of 2 arcmin added in quadrature). The SVOM/ECLAIRs light curve showed a single peak structure with a T90 duration of about 23.26 (-8.032 +4.41) s. The platform did not slew to the source. No observations could be performed in the X-rays by SVOM/MXT nor in the optical with SVOM/VT for the time being. The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. SVOM/ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. SVOM/GRM was developed by the Institute of High Energy Physics (IHEP) of CAS. SVOM/MXT was developed jointly by CNES, CEA-IRFU, CNRS-IJCLab, University of Leicester, MPE. The Burst Advocate (BA) on shift for this alert is Natalie Webb: natalie.webb(a)irap.omp.eu. Please contact the BA by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/42148. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40216] GRB 251007B: Swift detection of a burst
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42147 SUBJECT: GRB 251007B: Swift detection of a burst DATE: 25/10/07 20:05:03 GMT FROM: David Palmer at LANL <palmer(a)lanl.gov> A. Melandri (INAF-OAR), E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), R. Gupta (NASA GSFC), N. J. Klingler (GSFC/UMBC/CRESSTII), N. P. M. Kuin (UCL-MSSL) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 19:43:06 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 251007B (trigger=1402467). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 102.117, -10.303 which is RA(J2000) = 06h 48m 28s Dec(J2000) = -10d 18' 11" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Due to the continued on-board processing of the previous burst (GRB 251007A) the BAT lightcurve is not immediately available. The XRT began observing the field at 19:45:35.0 UT, 148.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 102.13232, -10.30328 which is equivalent to: RA(J2000) = 06h 48m 31.76s Dec(J2000) = -10d 18' 11.8" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 54 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 5.99 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 151 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image processing FAILED because of no aspect solution. Results from the list of sources generated on-board are not available at this time. No correction has been made for the expected extinction corresponding to E(B-V) of 0.785. Burst Advocate for this burst is A. Melandri (andrea.melandri AT inaf.it). 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/) View this GCN Circular online at https://gcn.nasa.gov/circulars/42147. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40215] GRB 251007A: Swift detection of a burst with an optical counterpart
by GCN Circulars 07 Oct '25

07 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42146 SUBJECT: GRB 251007A: Swift detection of a burst with an optical counterpart DATE: 25/10/07 19:53:26 GMT FROM: David Palmer at LANL <palmer(a)lanl.gov> E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), R. Gupta (NASA GSFC), N. J. Klingler (GSFC/UMBC/CRESSTII), N. P. M. Kuin (UCL-MSSL), A. Melandri (INAF-OAR), M. J. Moss (GSFC), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team: At 19:36:58 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 251007A (trigger=1402466). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 128.173, +21.823 which is RA(J2000) = 08h 32m 42s Dec(J2000) = +21d 49' 24" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with an initial sequence of peaks followed by a larger complex peak with a total duration of about 100 sec. The peak count rate was ~12000 counts/sec (15-350 keV), at ~56 sec after the trigger. The XRT began observing the field at 19:38:07.4 UT, 69.4 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 128.1775, 21.8138 which is equivalent to: RA(J2000) = 08h 32m 42.60s Dec(J2000) = +21d 48' 49.7" with an uncertainty of 5.4 arcseconds (radius, 90% containment). This location is 36 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT took a finding chart exposure of 150 seconds with the White filter starting 78 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 08:32:42.40 = 128.17665 DEC(J2000) = +21:48:46.1 = 21.81280 with a 90%-confidence error radius of about 0.63 arc sec. This position is 4.6 arc sec. from the center of the XRT error circle. The estimated magnitude is 18.38 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.039. Burst Advocate for this burst is E. Ambrosi (elena.ambrosi AT inaf.it). 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/) View this GCN Circular online at https://gcn.nasa.gov/circulars/42146. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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