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[vsnet-grb-info 43095] GRB 260614A: GECAM-B observation
by GCN Circulars 14 Jun '26

14 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44940 SUBJECT: GRB 260614A: GECAM-B observation DATE: 26/06/14 16:14:12 GMT FROM: Xinghao Luo at IHEP <2952704891(a)qq.com> Xing-Hao Luo, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered on-ground by GRB 260614A, at 2026-06-14T10:06:15.950 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #44935). According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 20 +/-6 s. The GECAM-B light curve can be found here: https://www.bursthub.cn//admin/static/gecambgrb260614A.png Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two micro-satellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS). View this GCN Circular online at https://gcn.nasa.gov/circulars/44940. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43094] GRB 260614B: SVOM/VT optical candidate from VHF data
by GCN Circulars 14 Jun '26

14 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44939 SUBJECT: GRB 260614B: SVOM/VT optical candidate from VHF data DATE: 26/06/14 15:06:45 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> J. T. Palmerio, A. Saccardi (CEA/Irfu), Y. L. Qiu, C. Wu, L. P. Xin (NAOC), M. Pillas (IAP) on behalf of the SVOM/VT team. After the trigger by SVOM/ECLAIRs at 2026-06-14T13:49:55 UTC (T0), SVOM performed an automatic slew on the burst location (Godet et al., GCN 44938). SVOM/VT began observing the field in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. From a preliminary analysis of the 1-bit subimage and source list downloaded via VHF network, at least one credible candidate is identified, the details of which are presented below. VT_ID 52: The position of this candidate is R.A., Dec. 353.90883, -54.11628 degrees, corresponding to: R.A. (J2000) = 23h35m38.1s Dec. (J2000) = -54d06m58.6s with an uncertainty of 0.50 arcsec. This candidate was detected in both VT_R and VT_Band was flagged as an uncatalogued source. The candidate's magnitudes are: | date-obs (UTC) | mid-time | exposure | VT_B mag(AB) | VT_R mag(AB) | | -------------------- | ----------- | --------- | ------------- | ------------- | | 2026-06-14T13:54:16 | 2026-06-14T13:56:46 | 6x50s | 19.25 ± 0.01 | 16.35 ± 0.01 | | 2026-06-14T13:59:16 | 2026-06-14T14:01:21 | 5x50s | – | 16.71 ± 0.01 | Magnitudes were not corrected for Galactic reddening. 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/VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS. 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/44939. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[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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