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

[vsnet-grb-info 42750] GRB 260515A: SVOM detection of a burst
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44622 SUBJECT: GRB 260515A: SVOM detection of a burst DATE: 26/05/15 19:36:12 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> M. Brunet, L. Bouchet (IRAP), A. Saccardi (CEA/Irfu), D. Gotz (CEA/Irfu) report on behalf of the SVOM mission team: At 2026-05-15T19:08:19 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 260515A (SVOM burst-id sb26051504). 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 17 alerts. CRT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 24.06 in the [5-20] keV energy band over a time window of 10.20 seconds starting at 2026-05-15T19:08:19. The localization of the best alert is R.A., Dec. 227.6800, 24.5706 degrees: R.A. (J2000) = 15h10m43.20s Dec. (J2000) = 24d34m14.13s with a 90% confidence level (C.L.) radius of 3.77 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 16.6 +/-1.5 s in the 5-120 keV. This burst was also detected by SVOM/GRM with a significance of 10.2 . SVOM slewed to the burst. MXT and VT began observing the field after the slew. The analysis of the data will be published in a future circular. 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 Andrea Saccardi (CEA): andrea.saccardi(a)cea.fr Please contact the BA by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/44622. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42749] GRB 260510C: Glowbug gamma-ray detection
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44621 SUBJECT: GRB 260510C: Glowbug gamma-ray detection DATE: 26/05/15 18:39:46 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 260510C, which was detected by Fermi/GBM (GCN 44520, 44564), SVOM (GCN 44521), MAXI/GSC (GCN 44526), AstroSat/CZTI (GCN 44544), and CALET (GCN 44616). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2026-05-10 17:15:37.096 with a duration of 4.1 s and a total significance of about 5.2 sigma. The lightcurve comprises a single peak corresponding to the portion of the burst observed by CALET/CGBM (GCN 44616). 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 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/44621. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42748] IceCube-260504A: No Candidate Transients from the Zwicky Transient Facility
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44620 SUBJECT: IceCube-260504A: No Candidate Transients from the Zwicky Transient Facility DATE: 26/05/15 18:10:11 GMT FROM: Robert David Stein at JSI <rdstein(a)umd.edu> Robert Stein (JSI), Jannis Necker (Leiden University), Akshay Eranhalodi (DESY), and Anna Franckowiak (Ruhr University Bochum) report, On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: As part of the ZTF neutrino follow up program (Stein et al. 2023), we observed the localization region of the neutrino event IceCube-260504A (IceCube Collaboration, GCN 44464) with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). We started observations in the g- and r-band beginning at 2026-05-07 04:25 UTC, approximately 55.2 hours after event time due to bad weather. We covered 68.2% (0.6 sq deg) of the reported localization region. This estimate accounts for chip gaps. Each exposure was 30s with a typical depth of 20.5 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019, Stein et al. 2021) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019) . No candidate counterparts were detected. ZTF and GROWTH are worldwide collaborations comprising Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan; OKC, Sweden; DZA, Germany. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering is performed with the nuztf (Stein et al. 2021, https://github.com/desy-multimessenger/nuztf ). View this GCN Circular online at https://gcn.nasa.gov/circulars/44620. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42747] EP260514a: GROWTH-India Telescope optical upper limit
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44619 SUBJECT: EP260514a: GROWTH-India Telescope optical upper limit DATE: 26/05/15 17:20:18 GMT FROM: V. Swain at IIT Bombay <vishwajeet.s(a)iitb.ac.in> T. Mohan (IITB), V. Vijaykumar (IITB), V. Swain (IITB), D. Eappachen (IIA), A.P. Saikia (IITB), S. Patil (IITB), V. Bhalerao (IITB), G.C. Anupama (IIA), S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team: We observed the field of EP260514a (Cheng et al., GCN 44613), with 0.7m GROWTH-India Telescope (GIT). We started the observation at 2026-05-15 16:27:06 (UTC), i.e., 0.98 days after the trigger, and obtained single exposure in the r' filter. We did not detect any transient in our image within the WXT localization region. The photometric upper limit is as follows: | MJD (mid) | Filter | tmid-t0 (hour) | Exposure Time (sec) | Upper limit (AB) | | ------------ | ------ | -------------- | ------------------- | ---------------- | | 61175.68756 | r' | 23.57 | 360 | 20.5 | The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. Our results are consistent with other optical observation (Lipunov et al., GCN 44614). The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/. View this GCN Circular online at https://gcn.nasa.gov/circulars/44619. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42746] GRB 260511B: NOT optical observations
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44618 SUBJECT: GRB 260511B: NOT optical observations DATE: 26/05/15 16:42:48 GMT FROM: sqjiang at NAOC <sqjiang(a)bao.ac.cn> S. Q. Jiang, D. Xu (NAOC), D. B. Malesani (DAWN/NBI and Radboud), J. P. U. Fynbo (DAWN/NBI), A. M. Kadela (NOT & NBI) report on behalf of a large collaboration: We observed the optical counterpart (Wu et al., GCNs 44547, 44552; Sasada et al., GCN 44549; Jiang et al., GCN 44551; Li et al., GCNs 44557, 44593; Vijaykumar et al., GCN 44561; de Ugarte Postigo et al., GCN 44565; Lee et al., GCN 44567; Li et al., GCN 44568; Wang et al., GCN 44571; Belkin et al., GCN 44572; Adami et al., GCN 44573; Saccardi et al., GCN 44574; Rajabov et al., GCN 44576; Pérez-Fournon et al., GCN 44577; Novotný et al., GCN 44580; Moskvitin et al., GCNs 44582, 44600; Calapai et al., GCN 44592; Liu et al., GCN 44610; Li et al., GCN 44615) of GRB 260511B, detected by Fermi/GBM (Fermi GBM Team, GCN 44542), SVOM (Godet et al., GCN 44543), NuSTAR (Waratkar & Grefenstette, GCN 44556), AstroSat CZTI (Arya et al., GCN 44560), and Konus-Wind (Ridnaia et al., GCN 44597) using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera, and obtained 3 x 90 s frames in each of the Sloan g, r, and i bands, and 3x200 s frames in the Sloan z band, starting at 21:12:00.450 UT on 2026-05-12, i.e., 34.192 hr after the Fermi/GBM trigger. The afterglow is clearly detected in our stacked images, with a magnitude r = 21.33 +/- 0.06 (AB) at a median time of 34.337 hr after the trigger, calibrated against nearby Pan-STARRS stars and not corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/44618. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42745] Konus-Wind detection of GRB 260512A
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44617 SUBJECT: Konus-Wind detection of GRB 260512A DATE: 26/05/15 10:45:03 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru> A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 260512A (Fermi-GBM detection: The Fermi GBM team, GCN 44587; NuSTAR-ACS detection: Waratkar et al., GCN 44591; AstroSat-CZTI detection: Tembhurnikar et al., GCN 44608; IPN triangulation: Kozyrev et al., GCN 44611) triggered Konus-Wind at T0=61005.883 s UT (16:56:45.883). The burst light curve shows a multipeaked structure which starts at ~T0-0.7 s and has a total duration of ~23 s. The emission is seen up to ~2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB260512_T61005/ As observed by Konus-Wind, the burst had the total fluence of 2.45(-0.24,+0.20)x10^-5 erg/cm2, and the 64-ms peak flux, measured from T0+4.464 s, of 6.32(-0.82,+0.83)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+24.832 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.99(-0.09,+0.09), the high energy photon index beta = -2.60(-0.46,+0.17), the peak energy Ep = 202(-16,+22) keV (chi2 = 117/98 dof). The spectrum near the maximum count rate (measured from T0+0.256 to T0+8.448 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.82(-0.08,+0.08), the high energy photon index beta = -2.53(-0.13,+0.10), the peak energy Ep = 193(-11,+13) keV (chi2 = 93/79 dof). All the quoted errors are at the 68% confidence level. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/44617. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42744] GRB 260510C: CALET Gamma-Ray Burst Monitor detection
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44616 SUBJECT: GRB 260510C: CALET Gamma-Ray Burst Monitor detection DATE: 26/05/15 07:23:20 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> T. Sakamoto, A. Yoshida, S. Sugita, Y. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The CALET Gamma-ray Burst Monitor (CGBM) detected GRB 260510C (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN #44520; SVOM detection of a burst: Gotz et al., GCN #44521; MAXI/GSC detection: Iwakiri et al., GCN #44526; AstroSat CZTI detection: Arya et al., GCN #44544; Fermi GBM Observation: Palafox et al., GCN #44564) at 17:15:37.60 UTC on 10 May 2026 (https://cgbm.calet.jp/cgbm_trigger/flight/1462468483/index.html) The burst signal was seen by all CGBM detectors. The onboard CGBM trigger corresponds to the second peak of the double-peaked structure reported by Fermi/GBM and SVOM/ECLAIRs. In the CGBM ground analysis, the first peak was also marginally visible in the SGM data. The second peak started at T+0.3 s, peaked at T+2.9 s, and ended at T+8.9 s. The T90 and T50 durations of the second peak, measured with the SGM data, are 7.4 +/- 0.8 s and 3.2 +/- 0.8 s in the 40-1000 keV band, respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1462468483/ The CALET data used in this analysis were provided by the Waseda CALET Operation Center located at Waseda University. View this GCN Circular online at https://gcn.nasa.gov/circulars/44616. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42743] GRB 260511B: GMG Optical Upper Limit
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44615 SUBJECT: GRB 260511B: GMG Optical Upper Limit DATE: 26/05/15 04:58:07 GMT FROM: Rui-Zhi Li at Yunnan Observatories, CAS <liruizhi(a)ynao.ac.cn> R.-Z. Li, B.-T. Wang, F.-F. Song, J. Mao, J.-G. Wang and B. Wang (YNAO, CAS) report: We observed the field of GRB 260511B (Godet et al., GCN 44543, T0 at 2026-05-11T11:00:32) using the GMG-2.4m telescope at the Lijiang Observatory. The observation began at 2026-05-14 12:45:02, about 73.74 hours after the trigger. The optical counterpart (Wu et al. GCN 44547, Sasada et al. GCN 44549, Jiang et al. GCN 44551, Wu et al. GCN 44552, Vijaykumar et al. GCN 44561, de Ugarte Postigo et al. GCN 44565, Lee et al. GCN 44567, Li et al. GCN 44568, Wang et al. GCN 44571, Belkin et al. GCN 44572, Adami et al. GCN 44573, Saccardi et al. GCN 44574, Rajabov et al. GCN 44576, Perez-Fournon et al. GCN 44577, Novotny et al. GCN 44580, Moskvitin et al. GCN 44582, Calapai et al. GCN 44592, Moskvitin et al. GCN 44600 and Liu et al. GCN 44610) of GRB 260511B was not detected in our r-band image. The preliminary analysis results are shown as follows: +-------------------------+----------------+---------------+----------+----------------+ | Start time [UTC] | Exposure [s] | Tmid-T0 [h] | Filter | 5-sigma U.L. | +=========================+================+===============+==========+================+ | 2026-05-14 12:45:02.730 | 900 | 73.867 | r | 21.6 | +-------------------------+----------------+---------------+----------+----------------+ The given magnitudes are derived based on calibrating against Pan-STARRS1 field stars. View this GCN Circular online at https://gcn.nasa.gov/circulars/44615. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42742] EP260514a: Global MASTER-Net observations report
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44614 SUBJECT: EP260514a: Global MASTER-Net observations report DATE: 26/05/15 03:27:20 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP260514a ( EP Team et al., GCN 44613) errorbox 35348 sec after trigger time at 2026-05-15 02:45:14 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 81 deg. The sun altitude is -63.2 deg. The galactic latitude b = 62 deg., longitude l = 91 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3315353 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 35378 | 2026-05-15 02:45:14 | MASTER-OAFA | (14h 15m 58.14s , +49d 22m 48.5s) | C | 60 | 18.0 | 35443 | 2026-05-15 02:46:19 | MASTER-OAFA | (14h 15m 57.12s , +49d 22m 52.2s) | C | 60 | 18.0 | 35509 | 2026-05-15 02:47:24 | MASTER-OAFA | (14h 15m 56.10s , +49d 22m 55.1s) | C | 60 | 18.3 | 35575 | 2026-05-15 02:48:31 | MASTER-OAFA | (14h 15m 54.95s , +49d 22m 57.3s) | C | 60 | 18.2 | 35641 | 2026-05-15 02:49:37 | MASTER-OAFA | (14h 15m 54.43s , +49d 23m 01.2s) | C | 60 | 18.3 | 35701 | 2026-05-15 02:49:37 | MASTER-OAFA | (14h 15m 54.41s , +49d 23m 01.1s) | C | 180 | 18.6 | Coadd 35707 | 2026-05-15 02:50:42 | MASTER-OAFA | (14h 15m 54.22s , +49d 23m 03.8s) | C | 60 | 18.2 | 35773 | 2026-05-15 02:51:49 | MASTER-OAFA | (14h 15m 54.02s , +49d 23m 06.1s) | C | 60 | 17.9 | 35838 | 2026-05-15 02:52:54 | MASTER-OAFA | (14h 15m 53.77s , +49d 23m 08.7s) | C | 60 | 18.0 | 35904 | 2026-05-15 02:53:59 | MASTER-OAFA | (14h 15m 53.54s , +49d 23m 11.4s) | C | 60 | 18.1 | 35970 | 2026-05-15 02:55:05 | MASTER-OAFA | (14h 15m 53.30s , +49d 23m 11.7s) | C | 60 | 18.2 | 36035 | 2026-05-15 02:56:11 | MASTER-OAFA | (14h 15m 53.06s , +49d 23m 14.8s) | C | 60 | 18.4 | 36101 | 2026-05-15 02:57:16 | MASTER-OAFA | (14h 15m 52.80s , +49d 23m 16.2s) | C | 60 | 18.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/44614. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42741] EP260514a: Einstein Probe detection of a fast X-ray transient
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44613 SUBJECT: EP260514a: Einstein Probe detection of a fast X-ray transient DATE: 26/05/15 03:20:32 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.-H. Cheng (SWIFAR, YNU), K.R. Ni (CCNU), R.-Z. Li (YNAO, CAS) and W.-D. Zhang (NAO, CAS) on behalf of the Einstein Probe (EP) team: We report on the detection of a fast X-ray transient by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated EP260514a. The ground analysis of the WXT data shows that the event started at T0 = 2026-05-14T16:56:06 (UTC) and lasted for around 500 s. The WXT position of the source is R.A. = 214.297 deg, DEC = 49.365 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). A follow-up observation with the Follow-up X-ray Telescope (FXT) on board EP has been scheduled. Further information will be updated when the telemetry data is received. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/44613. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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