June 2026 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 43093] GRB 260614B: SVOM detection of a burst
by GCN Circulars 14 Jun '26

14 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44938 SUBJECT: GRB 260614B: SVOM detection of a burst DATE: 26/06/14 14:17:03 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> O. Godet (IRAP), M. Pillas (IAP), D. Götz (CEA), F. Robinet (IJCLAB) report on behalf of the SVOM mission team: At 2026-06-14T13:49:55 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 260614B (SVOM burst-id sb26061401), also detected by Fermi/GBM (GCN #44937). 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 15 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 40.78 in the [8-120] keV energy band over a time window of 20.48 seconds starting at 2026-06-14T13:49:52. The localization of the best alert is R.A., Dec. 353.940, -54.154 degrees: R.A. (J2000) = 23h35m45.60s Dec. (J2000) = -54d09m13.40s with a 90% confidence level (C.L.) radius of 2.75 arcmin (including systematic error of 2 arcmin added in quadrature). The SVOM/ECLAIRs light curve showed a multiple broad peak structure with a T90 duration of about 19.62 -2.19 / +5.93 s. This burst also triggered SVOM/GRM at 2026-06-14T13:49:47 on a timescale of 4 seconds with an SNR of 5.10. SVOM slewed to the burst. SVOM/MXT began observing the field at 2026-06-14T13:52:24.0 UTC. Using onboard processed data we found an uncatalogued X-ray source located at R.A., Dec. 353.907, -54.1192 degrees with a 90% C.L. radius of 69 arcseconds. This location is arcminutes from the ECLAIRs onboard position. This position may be improved as more data is received. 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 Marion Pillas: marion.pillas(a)iap.fr. Please contact the BA by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/44938. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43092] GRB 260614B: Fermi GBM Final Real-time Localization
by GCN Circulars 14 Jun '26

14 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44937 SUBJECT: GRB 260614B: Fermi GBM Final Real-time Localization DATE: 26/06/14 13:57:42 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 13:49:53 UT on 14 Jun 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260614B (trigger 803137798.515116 / 260614576). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 2.5, Dec = -50.9 (J2000 degrees, equivalent to J2000 00h 10m, -50d 53'), with a statistical uncertainty of 2.7 degrees. The angle from the Fermi LAT boresight is 25.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260614576/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260614576/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260614576/… View this GCN Circular online at https://gcn.nasa.gov/circulars/44937. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43091] GRB 260611B: SVOM/GRM detection
by GCN Circulars 14 Jun '26

14 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44936 SUBJECT: GRB 260611B: SVOM/GRM detection DATE: 26/06/14 13:54:22 GMT FROM: zhangjinpeng(a)ihep.ac.cn SVOM/GRM team: Jin-Peng Zhang, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Marius Brunet (IRAP) Report on behalf of the SVOM team: SVOM/GRM detected GRB 260611B during the routine ground search at 2026-06-11T21:32:37.000 (T0), which is also detected by Fermi/GBM (Fermi GBM Team, GCN #44917) and CALET (Nakahira et al, GCN #44923). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst mainly consists of multiple pulses with a T90 of 26 +4/-2 s in the 15-5000 keV band. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb260611B.png In addition, the position of this burst, according to Fermi/GBM localization (RA = 13.3, Dec = 22.6, Fermi GBM Team, GCN #44917), is located at about 121 degrees from the SVOM optical axis, which is outside the ECLAIRs field of view. With this localization, the time-averaged spectrum from T0-6 to T0+26 s is fitted by a power law function. The power law index is -2.14 +0.12/-0.12. The event fluence (10-1000 keV) in this time interval is (1.41 +0.13/-0.13)E-05 erg/cm^2. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM/GRM point of contact for this burst is: Jin-Peng Zhang (IHEP) (zhangjinpeng(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/44936. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43090] GRB 260614A: Fermi GBM Final Localization
by GCN Circulars 14 Jun '26

14 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44935 SUBJECT: GRB 260614A: Fermi GBM Final Localization DATE: 26/06/14 11:49:11 GMT FROM: Rushikesh Sonawane at IISER TVM <rushikesh23(a)iisertvm.ac.in> The Fermi GBM team reports the detection of a likely LONG GRB "At 10:06:14.62 UT on 14 June 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260614A (trigger 803124379/260614421). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 192.76, Dec = -38.51 (J2000 degrees, equivalent to J2000 12h 51m, -38d 30'), with a statistical uncertainty of 6.04 degrees. The angle from the Fermi LAT boresight is 106 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260614421/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260614421/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260614421/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/44935. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43089] The EP-WXT trigger 01709269488 is likely a flaring star
by GCN Circulars 14 Jun '26

14 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44934 SUBJECT: The EP-WXT trigger 01709269488 is likely a flaring star DATE: 26/06/14 06:18:14 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.-H. I. Yin (HKU), G. Y. Zhao (SYSU), Z. M. Wang (BNU) and W. D. Zhang (NAO,CAS) on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709269488 at the time of 2026-06-14T05:58:28, is likely a stellar flare associated with Wolf 1473 (Spectroscopic Binary). The estimated flux of the flare is around 1 x 10^(-10) erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 2 x 10^30 erg/s. 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/44934. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43088] GRB 260603C: AstroSat CZTI detection
by GCN Circulars 14 Jun '26

14 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44933 SUBJECT: GRB 260603C: AstroSat CZTI detection DATE: 26/06/14 00:21:34 GMT FROM: Gaurav Waratkar at Caltech <gauravwaratkar(a)iitb.ac.in> S.Salunke (IUCAA), Harsha K. H. (IUCAA), A. Goyal (IITB), A. Arya (IITB), G. Waratkar (Caltech/IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 260603C. The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2026-06-03 20:22:40.3. The measured peak count rate associated with the burst is 83 (+25, -18) counts/s above the background in the combined data of two quadrants (out of four), with a total of 1141 (+467, -343) counts. The local mean background count rate was 150 (+0.7, -2) counts/s. We measure a T90 of 71 (+25, -13) s from the cumulative CZT light curve. The source was faintly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve, with a single burst of emission, peaks at 2026-06-03 20:22:40.2. The measured peak count rate associated with the burst is 250 (+71, -36) counts/s above the background in the combined data of all quadrants, with a total of 822 (+283, -302) counts. The local mean background count rate was 1204 (+8, -8) counts/s. We measure a T90 of 5 (+4, -2) s from the cumulative Veto light curve, much lower than the T90 estimated in CZT detectors. We attribute this to a likely unfavorable angle from the boresight for Veto detectors. CZTI data products like interactive and downloadable light curves for this GRB can be found at: http://astrosat.iucaa.in/cift/cift_products/518214162.17/S518214162.17_deta… CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project. CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb View this GCN Circular online at https://gcn.nasa.gov/circulars/44933. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43087] GRB 260610B: further Liverpool Telescope optical observations
by GCN Circulars 13 Jun '26

13 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44932 SUBJECT: GRB 260610B: further Liverpool Telescope optical observations DATE: 26/06/13 19:36:46 GMT FROM: A. Bochenek at Liverpool John Moores University <a.m.bochenek(a)2023.ljmu.ac.uk> A. Bochenek, D. A. Perley (LJMU), report: We observed the field of the optical counterpart (O'Neil et al., GCN 44903) of GRB 260610b (Fu et al., GCN 44901) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 5x120s exposures in SDSS griz filters, starting at 2026-06-13 01:22:29 UT, approximately 2.07 days after Fermi trigger. Some exposures had to be discarded prior to stacking. We detect a source in the images in all filters at the position reported by O'Neil et al. (GCN 44903), observed also by Watson et al. (GCN 44905); Zhu et al. (GCN 44909); Gillanders et al. (GCN 44910); Akl et al. (GCN 44911); O'Neill et al. (GCN 44914); Moskvitin et al. (GCN 44918); Jackson-Horne et al. (GCN 44919); Izzo, (GCN 44920), Li et al. (GCN 44921), Bochenek et al. (GCN 44927), Moskvitin et al. (GCN 44929); and Akl et al. (GCN 44930) . The photometry is: | MJD (mid) | T_mid-T_0 | Filter | Mag. (AB) | |---------------|-------------|-----------|---------------| | 61204.05962 | 49.66 h | r | 21.05 ± 0.07 | | 61204.07237 | 49.97 h | i | 20.61 ± 0.09 | | 61204.07751 | 50.08 h | z | 20.28 ± 0.12 | | 61204.08753 | 50.33 h | g | 21.40 ± 0.14 | The photometry was calibrated using nearby PanSTARRS secondary standards and was not corrected for extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/44932. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43086] GRB 260610B: Fermi GBM Observation
by GCN Circulars 13 Jun '26

13 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44931 SUBJECT: GRB 260610B: Fermi GBM Observation DATE: 26/06/13 18:21:44 GMT FROM: Matt Godwin <msg0028(a)uah.edu> Matt Godwin (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 23:46:14.25 UT on 10 June 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260610B (trigger 802827979/260610990). An optical counterpart is identified by GOTO (O'Neill, et al. 2026, GCN 44903). The redshift of the source is measured to be z = 0.473, ALFOSC/NOT (ONeill et al. 2026, GCN 44914). The Fermi GBM on-ground location is consistent with the GOTO position. The angle from the Fermi LAT boresight is 97 degrees. The GBM light curve consists of three peaks with a duration (T90) of about 62 s (50-300 keV). The time-averaged spectrum from T0-2.4 to T0+55.4 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.50 +/- 0.01 and the cutoff energy, parameterized as Epeak, is 46.8 +/- 0.4 keV. The event fluence (10-1000 keV) in this time interval is (1.30 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.8 s in the 10-1000 keV band is 7.7 +/- 0.3 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 45.9 +/- 0.5 keV, alpha = -1.4800 +/- 0.0009 and beta = -3.17 +/- 0.01. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/" View this GCN Circular online at https://gcn.nasa.gov/circulars/44931. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43085] GRB 260610B / AT2026owq: GRANDMA optical observations
by GCN Circulars 13 Jun '26

13 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44930 SUBJECT: GRB 260610B / AT2026owq: GRANDMA optical observations DATE: 26/06/13 13:50:34 GMT FROM: Dalya Akl at New York University Abu Dhabi <dka2010(a)nyu.edu> D. Akl (NYUAD), M. Mašek (FZU), R. Hanna (IJCLAB), P. Putsathan (KKU), Y. Rajabov (UBAI), S. Antier (IJCLAB), P. Hello (IJCLAB), M. Coughlin (UNM), S. Karpov (FZU), M. Pillas (IAP), C. Douzet (IJCLAB), A. Simon (TShNU of Kyiv), D. Rusanova (TShNU of Kyiv), V. Vasylenko (NC JASU), O. Burkhonov (UBAI), S. Ehgamberdiev (UBAI), Y. Tillayev (UBAI), P. Put (NARIT), K. Noysena (NARIT), M. Tanasan (CMU/NARIT), D. Turpin (CEA-Saclay/Irfu), M. Freeberg (KNC), A. Klotz (IRAP), C. Limonta (OCA), A. Dupin (OCA), Q. André (OCA), M. Molham (NRIAG), E. Elhosseiny (NRIAG), A. Takey (NRIAG), N. Kochiashvili (AbAO), R. Inasaridze (AbAO), V. Zhuzhunadze (AbAO) on behalf of the GRANDMA collaboration: We observed the field of the Fermi Long GRB 260610B (Fermi GBM team, GCN 44901). The observations started at 16:29:50 UTC on the 11 of June 2026, 0.7 days post the Fermi Trigger. We detected the optical afterglow candidate, reported by GOTO (O'Neill et al, GCN 44903), in several epochs, using TRT-SRO in California state, UBAI-NT60, UBAI-AZT-22 at Madainak Observatory, AZT-8 at Lisnyky Observatory, KAO-1.88m at Kottamia Astronomical Observatory, TAROT-TCA/TCH at Calern and La Silla, and Kilonova Catcher. A subset of the photometry corrected for Galactic extinction is reported in the public ACME service Skyportal/ICARE https://skyportal-icare.ijclab.in2p3.fr/source/2026owq. To access, one simply needs to create an account using your ORCID ID. The data were reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). Images obtained with the Sloan filters were calibrated using the PanSTARRS DR1 catalog. Images obtained with the Johnson-Cousins filters were calibrated using the Gaia DR3 Synphot catalog. The observations are performed under the P7 campaign of GRANDMA to monitor SVOM alerts and LSST alerts from explosive fast transients filtered by BOOM/Babamul and FINK. The results are consistent with other measurements reported (Zhu et al., GCN 44909; Akl et al., GCN 44911; O'Neill et al., GCN 44914; Moskvitin et al., GCN 44918; Jackson-Horne et al., GCN 44919; Li et al., GCN 44921; Bochenek and Perley, GCN 44927; Moskvitin et al., GCN 44929) GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/) View this GCN Circular online at https://gcn.nasa.gov/circulars/44930. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43084] GRB 260610B / AT2026owq: further SAO RAS optical observations
by GCN Circulars 13 Jun '26

13 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44929 SUBJECT: GRB 260610B / AT2026owq: further SAO RAS optical observations DATE: 26/06/13 06:35:11 GMT FROM: Alexander Moskvitin at SAO RAS <mosk(a)sao.ru> A. Moskvitin (SAO RAS), O. Spiridonova (SAO RAS), A. Pozanenko (IKI), A. Volnova (IKI), N. Pankov (IKI) report on behalf of GRB follow-up team We observed the field of GRB 260610B discovered by Fermi (The Fermi GBM team, GCN 44891; GCN 44901) with the Zeiss-1000 1-m telescope of SAO RAS + CCD photometer in BVRcIc filters on June 12. The OT (O'Neill et al., GCN 44903; Watson et al., GCN 44905; Zhu et al., GCN 44909; Gillanders et al., GCN 44910; Akl et al., GCN 44911; O'Neill et al., GCN 44914; Moskvitin et al., GCN 44918; Jackson-Horne et al., GCN 44919; Izzo, GCN 44920; Li et al., GCN 44921; Bochenek and Perley, GCN 44927) is clearly detected in our frames with the following brightness: Date, UTstart, t-T0, Exp., Filter, Mag, Err., UL (mid,d) (n*s) (3-sigma) 2026-06-12 19:21:03 2.41821 5*300 Rc 20.61 0.03 23.5 This preliminary photometry is based on nearby SDSS stars (using Lupton 2005 transformation equations) and not corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/44929. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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