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

[vsnet-grb-info 43351] GRB 260709A: SVOM/GRM detection
by GCN Circulars 11 Jul '26

11 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45137 SUBJECT: GRB 260709A: SVOM/GRM detection DATE: 26/07/11 05:58:51 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: Sebastien Guillot (IRAP) Report on behalf of the SVOM team: SVOM/GRM detected GRB 260709A during the routine ground search at 2026-07-09T01:07:50.900 (T0), which is also detected by Fermi/GBM (Fermi GBM Team, GCN #45121). 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 63 +9/-9 s in the 15-5000 keV band. The SVOM/GRM light curve can be found here: https://www.bursthub.cn/gcn/2026/svgrb260709A.png In addition, the position of this burst, according to Fermi/GBM localization (RA = 84.1, Dec = 74.0, Fermi GBM Team, GCN #45121), is located at about 119 degrees from the SVOM optical axis, which is outside the ECLAIRs field of view. With this localization, the time-averaged spectrum from T0-25 to T0+25 s is fitted by a power law function. The power law index is -2.87 +0.16/-0.09. The event fluence (10-1000 keV) in this time interval is (3.0 +1.0/-1.2)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/45137. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43350] GRB 260709A: GECAM-B observation
by GCN Circulars 11 Jul '26

11 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45136 SUBJECT: GRB 260709A: GECAM-B observation DATE: 26/07/11 05:57:32 GMT FROM: zhangjinpeng(a)ihep.ac.cn Jin-Peng Zhang, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered in-flight by GRB 260709A, at 2026-07-09T01:07:32.000 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45121). According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of several pulses, with a duration (T90) of 56 +5/-4 s. The GECAM-B light curve can be found here: https://www.bursthub.cn/gcn/2026/gecambgrb260709A.png The time-averaged spectrum from T0 - 5 to T0 + 50 s (photon energy > 70 keV) is fitted by a power law function. The power law index is -2.38 +0.25/-0.25. The event fluence (10-1000 keV) in this time interval is (1.5 +0.5/-0.3)E-05 erg/cm^2. 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/45136. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43349] The EP-WXT trigger 01709274666 is likely a flaring star
by GCN Circulars 11 Jul '26

11 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45135 SUBJECT: The EP-WXT trigger 01709274666 is likely a flaring star DATE: 26/07/11 01:06:54 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.-H. I. Yin (HKU), R. Shi (PMO, CAS), F.-F. Song (YNAO, CAS), Y. Wu (NJU) and C. C. Jin (NAO, CAS) on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709274666 at the time of 2026-07-10T18:07:01, is likely a stellar flare associated with SS Cyg (Cataclysmic Binary). The estimated flux of the flare is around 3.2 x 10^(-10) erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 5 x 10^32 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/45135. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43348] IceCube-260708A: Observations with the Vera C. Rubin Observatory
by GCN Circulars 10 Jul '26

10 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45134 SUBJECT: IceCube-260708A: Observations with the Vera C. Rubin Observatory DATE: 26/07/10 19:24:52 GMT FROM: Robert David Stein at JSI <rdstein(a)umd.edu> Robert Stein (UMD/NASA GSFC/JSI), Sean MacBride (University of Zürich), Tiago Ribeiro, Lynne Jones, Angelo Fausti, Marina Pavlovic, Kris Mortensen, Jacqueline Seron Navarrete, Carlos Morales, Leanne Guy, Brian Stalder, Bob Blum (NSF-DOE Vera C Rubin Observatory), Erin Howard, Eric Bellm (University of Washington), Igor Andreoni (UNC Chapel Hill), Michael Coughlin (University of Minnesota), Antonella Palmese (Carnegie Mellon), Yousuke Utsumi (National Astronomical Observatory of Japan), Bruno Sanchez (CPPM - IN2P3), and Robert Lupton (Princeton), report on behalf of NSF-DOE Vera C Rubin Observatory: We observed the localization region of the high-energy neutrino event IceCube-260708A (Zegarelli et. al, GCN 45120) with the 9.6 square degree field of view LSST Camera mounted on the 8.4-m Simonyi Survey Telescope at the Vera C. Rubin Observatory [1]. The neutrino event met the pre-approved trigger criteria for neutrino follow-up with Rubin [2], and observations were conducted following the community-designed plan. The first night of observations consisted of exposures in u (30s), g (4x30s), r (30s) and z (30s). We started observations at 2026-07-10 02:48:12 UTC, approximately 33.5 hours after event time. These observations achieved the following single-visit median depths: u: 20.5 g: 22.8 (across four visits) r: 23.5 z: 22.1 Though the Legacy Survey of Space and Time (LSST) survey has now begun, template images are not yet available for most filters in this region of the sky. For the images acquired on the night of July 9, 2026, approximately 5000 alerts were generated from our z-band observations. While our automated alert system relies on production-quality templates to function autonomously, we have mobilized a specialized team of Rubin staff to process these images offline using lower quality templates that have been acquired in the region, but do not yet meet the standards for deployment to alert production. Any candidates will be reported to the community via GCN, and reported to TNS. Observations of the neutrino will continue as part of the community observing plan. We thank everyone in the Rubin Project and the wider Rubin Science Community who contributed to the success of these observations. This material is based upon work supported in part by the National Science Foundation through Cooperative Agreements AST-1258333 and AST-2241526 and Cooperative Support Agreements AST-1202910 and 2211468 managed by the Association of Universities for Research in Astronomy (AURA), and the Department of Energy under Contract No. DE-AC02-76SF00515 with the SLAC National Accelerator Laboratory managed by Stanford University. Additional Rubin Observatory funding comes from private donations, grants to universities, and in-kind support from LSST-DA Institutional Members. [1] Ivezić et al. (2019), https://arxiv.org/abs/0805.2366 [2] Andreoni et al. (2024), https://arxiv.org/abs/2411.04793 View this GCN Circular online at https://gcn.nasa.gov/circulars/45134. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43347] EP-WXT trigger 0170924151 : RAPAS optical counterpart candidate detection
by GCN Circulars 10 Jul '26

10 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45133 SUBJECT: EP-WXT trigger 0170924151 : RAPAS optical counterpart candidate detection DATE: 26/07/10 17:13:50 GMT FROM: Thierry Midavaine at SAF - RAPAS <thierrymidavaine(a)sfr.fr> Pierre-Yves Lechapelain and Thierry Midavaine report on behalf of the RAPAS network: the field of EP-0170924151 (Y.F. Liang et al. GCN 45095) was observed using a N254mm F/3 robotic telescope equiped with a CMOS FPA IMX533 at Observatoire de Bretagne Sud (Y80). The filters used were RAPAS filters meeting the Gaia G, Gbp, Grp photometric bands and astrometry was done with the GaiaDR3 catalogue. The observations began 20 minutes after the EP-WXT trigger (Jul 06, 22:18 UTC) and continued for 60 minutes with 120s exposures using a cycle of RAPAS G, Gbp and Grp filters. A follow-up epoch was obtained 24.2 hours later (Jul 07, 22:08 UTC) with 30s exposures. We identify the optical counterpart as the high-proper-motion M-dwarf star from the Gaia DR3 catalog : EP-WXT designation RA(J2000) = 239.6790° ; Dec(J2000) = 23.873° ; ±0.0520°. Our astrometry gives RA(J2000) = 239.6871° ; Dec(J2000) = 23.8549°; ±0.0001°, which is a mean value from 11 acquisitions in G and Grp bands. The target is found close to the Gaia DR3 source J15587+2351E, PM 1218502635856444672, RA = 239,6879070°, Dec = 23,8551800°, G=12.855, BP-RP=2.89. The angular difference between the target and the above Gaia source is around 0.001°. The shift seems in agreement with the Gaia measured proper motion of this Gaia DR3 source. Forced aperture photometry at the source position, calibrated against Gaia DR3 with a linear color term, yields the following G, Gbp Grp magnitudes and Gbp-Grp color index : MJD (mid) G mag G std Gbp mag Grp mag Gbp-Grp 61227.92963 12.13 0.72 12.70 11.65 1.05 61227.93420 12.19 0.64 12.76 11.46 1.30 61227.93895 12.30 0.54 12.86 11.57 1.29 61227.94359 12.38 0.46 13.02 11.61 1.41 61227.94815 12.46 0.37 13.19 11.59 1.60 61227.95297 12.59 0.25 13.29 11.71 1.58 61227.95763 12.61 0.23 13.37 11.76 1.61 61227.96211 12.67 0.17 13.50 11.78 1.72 61227.96678 12.67 0.19 13.47 11.80 1.67 61227.97132 12.71 0.13 13.52 11.82 1.70 61228.92248 13.14 0.29 We conclude that EP 01709274151 is a stellar flare from the nearby M-dwarf PM J15587+2351E. Further multi-band monitoring and SED are encouraged to characterize the recovery timescale. All the FITS files are available on request and are on the way to be archived in PADC facility for RAPAS at Paris Observatory. Acknowledgements : RAPAS ( https://gemini.obspm.fr/20220101-rapas/ ) is a ProAm collaboration created by T. Midavaine (SAF), W. Thuillot (LTE, Obs. de Paris-PSL) and M. Dennefeld (IAP/CNRS and Sorbonne Univ.) and funded by the Paris Observatory under API ProAm of the Scientific Council. It aims at homogenizing observing procedures and filters, and is delivering to a network of french amateur observatories a set of 3 filters which have been chosen to meet the Gaia G, Gbp and Grp spectral bands. This network produces data on astrophysical alerts delivered by various Alert systems (Gaia Alerts, Atlas, ZTF, etc…) and collected by Astro-COLIBRI ( https://astro-colibri.science ). It is similarly progressing towards an homogeneous spectroscopic equipment to deliver SED. Paris Observatory PADC which is on the way to archive all the FITS files with attached processing pipeline. View this GCN Circular online at https://gcn.nasa.gov/circulars/45133. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43346] GRB 260705C: AstroSat CZTI detection
by GCN Circulars 10 Jul '26

10 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45132 SUBJECT: GRB 260705C: AstroSat CZTI detection DATE: 26/07/10 15:48:52 GMT FROM: Anuraag Arya at IIT Bombay <aryaanuraag910(a)gmail.com> A. Goyal (IITB), A. Arya (IITB), Harsha K. H. (IUCAA), S. Salunke (IUCAA), 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 short GRB 260705C which was also detected by Fermi (GBM Team, GCN Circ. 45082) and Glowbug (Cheung et al., GCN Circ. 45104). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-07-05 13:58:59 UTC. The measured peak count rate associated with the burst is 310 (+130, -113) counts/s above the background in the combined data of two quadrants (out of four), with a total of 48 (+18, -18) counts. The local mean background count rate was 123 (+9, -10) counts/s. We measure a T90 of 0.27 (+0.11, -0.15) s from the cumulative CZT light curve. We note that the burst is relatively weak, hence theT90 measurement has a larger uncertainty than usual. CZTI data products like interactive and downloadable light curves for this GRB can be found at: https://astrosat.iucaa.in/cift/cift_products/ET20260705T135858/ET20260705T1… 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/45132. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43345] GRB 260710A: Fermi GBM Final Real-time Localization
by GCN Circulars 10 Jul '26

10 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45131 SUBJECT: GRB 260710A: Fermi GBM Final Real-time Localization DATE: 26/07/10 13:09:14 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 12:58:43 UT on 10 Jul 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260710A (trigger 805381128.521136 / 260710541). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 5.6, Dec = -85.0 (J2000 degrees, equivalent to J2000 00h 22m, -85d 00'), with a statistical uncertainty of 1.8 degrees. The angle from the Fermi LAT boresight is 135.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260710541/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260710541/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260710541/… View this GCN Circular online at https://gcn.nasa.gov/circulars/45131. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43344] GRB 260708A: Glowbug gamma-ray detection
by GCN Circulars 10 Jul '26

10 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45130 SUBJECT: GRB 260708A: Glowbug gamma-ray detection DATE: 26/07/10 11:25:29 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 260708A, which was also detected by Fermi/GBM (GCN 45115, 45124), Fermi/LAT (GCN 45117), and GECAM-B (GCN 45126), and has a proposed optical counterpart (GCN 45123, 45127). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2026-07-08 10:11:15.952 with a duration of 12.3 s and a total significance of about 7.7 sigma. The emission seen by Glowbug corresponds to the brightest portion of the GBM and GECAM-B light curves. 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/45130. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43343] GRB 260704A: SVOM/ECLAIRs refined analysis
by GCN Circulars 10 Jul '26

10 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45129 SUBJECT: GRB 260704A: SVOM/ECLAIRs refined analysis DATE: 26/07/10 07:41:16 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> GRB 260704A: SVOM/ECLAIRs refined analysis Wenjin Xie (NAOC), Marius Brunet (IRAP), Olivier Godet (IRAP), Floriane Cangemi (APC), Xiao Tian (GXU), Yehao Cheng (YNU) report on behalf of the SVOM/ECLAIRs team Using the event-by-event data downloaded through the X-band ground station, we report further analysis of SVOM/ECLAIRs observations of GRB 260704A (SVOM burst-id sb26070403 – GCN 45072, trigger time T0 = 2026-07-04T03:41:05 UTC). The burst shows a multiple peak lightcurve, with a precursor between T0-41s and T0 s, and a main pulse from T0+105 s to T0+160 s. The burst duration is T90 = 166 +10/-7 s in the 4-120 keV energy band. Considering the main pulse data, the refined burst localization we obtained is R.A., Dec = 318.631, -25.532 degrees : R.A. (J2000) = 21h14m31.44s Dec. (J2000) = -25d31m55.20s with a 90% confidence level (C.L.) radius of 5.2 arcmin (including systematic error of 2 arcmin added in quadrature). We note that the refined ECLAIRs central position is 4.33 arcmin from the X-ray counterpart position mentioned by the SVOM/MXT (W.J. Xie et al., GCN Circ. 45072) , and 4.79 from the position provided by EP/FXT (Y.-H. I. Yin et al., GCN Circ. 45078). The time-averaged spectrum from T0-41 s to T0 s (precursor) in the 5-120 keV energy range is best fitted by a powerlaw model with best-fit parameters alpha = -2.71 +/- 0.31. the 4-120 keV fluence is 1.7 +0.1/-0.7 erg/cm² (photon flux is 0.29 +0.01/-0.11 ph/cm²/s) . For the main pulse, the time-averaged spectrum from from T0+105 s to T0+160 s in the 5-120 keV energy range is best fitted by a powerlaw model with alpha = -1.96 +/- 0.12, the 4-120 keV fluence is 6.1 +0.5/-0.7 erg/cm² (photon flux is 0.48 +0.01/-0.05 ph/cm²/s) . The values of the photon index may imply that the peak energy of the burst is less than 5 keV. If so, GRB 260704A shall be classified as an X-ray flash The SVOM/ECLAIRs point of contact for this burst is: Wenjin XIE (NAOC) (xiewj(a)bao.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/45129. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43342] GRB 260706A : GRANDMA Upper limits
by GCN Circulars 09 Jul '26

09 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45128 SUBJECT: GRB 260706A : GRANDMA Upper limits DATE: 26/07/09 17:52:30 GMT FROM: antier(a)ijclab.in2p3.fr K. Agabi (OCA), A. Simon (TShNU of Kyiv), L. Wyrzykowski (Uni. Warsaw/NCBJ), A. Guštin (UNG School of Science, GoChile), J. Hambsch (VVS, GEOS, BAV), S. Antier (IJCLAB), M. Pillas (IAP), L. Abe (OCA), T T. Guillot (OCA). X. Sheng (QUB), P. Gokuldass (ERAU), E. Elhosseiny (KAO), O. Sokoliuk (UKyiv), Y. Rajabov (UBAI), Z. Maksut NU), E. Jehin (U of Liège), M. Ferrais (U of Liège) on behalf of GRANDMA collaboration: We observed the field of GRB 260706A detected by SVOM/ECLAIRs (GCN 45089), SVOM/GRM and Fermi-GBM (GCN 45088) and its counterpart detected by EP-FXT (GCN 45097, GCN 45114). The observations started at 20:30:00 UTC on the 6 of July 2026, 4.3 post ECLAIRs T0 with ASTEP and last about 1 day in all the network. We didn't detect any optical counterpart at the EP location (and near by) with GRANDMA, using 0.4m GoT1 telescope of University of Nova Gorica hosted at El Sauce Observatory in Chile, 0.6m TRAPPIST-South, 14" telescope at Franz-Josef Hambsch's Remote Observatory Atacama Dessert (ROAD) in Chile, ASTEP-50cm at Concordia, 1m LCO-SAAO telescope in South Africa with observatory in multiple epochs and filters. We reported our upper limit in the public ACME service Skyportal/ICARE https://skyportal-icare.ijclab.in2p3.fr/source/GCN-260706_161221. To access, one simply needs to create an account using your ORCID id. Our upper limit are coherent with REM (GCN 45100), LCO-1m (GCN 45098), and SVOM/VT (GCN 45113). 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. 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). Astrophysics Center for Multimessenger studies in Europe is supported Skyportal/ICARE (contact camille.douzet(a)ijclab.in2p3.fr, skyportal.io). View this GCN Circular online at https://gcn.nasa.gov/circulars/45128. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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