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

[vsnet-grb-info 43223] GRB 260619A: TRT optical counterpart confirmation
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45008 SUBJECT: GRB 260619A: TRT optical counterpart confirmation DATE: 26/06/19 16:30:48 GMT FROM: L. B. He at NAOC <helb(a)bao.ac.cn> L.B. He (NAOC), K. Noysena, K. Chanchaiworawit, S. Tinyanont (NARIT), S.Y. Fu (HUST), J. An, X. Liu, Z.P. Zhu, S.Q. Jiang, D. Xu (NAOC) report: We observed the field of GRB 260619A detected by SVOM/ECLAIRs (Goto et al., GCN 44985) using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Cerro Tololo Inter-American Observatory, Chile (CTO). The previously reported optical counterpart (Ducoin et al., GCN 44999; Li et al., GCN 45003) is detected in our stacked images with a brightness of r~21.4 at a median time of 3.95 hrs post-trigger, calibrated with Pan-STARRS DR2 stars in the field and not corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/45008. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43222] GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45007 SUBJECT: GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection DATE: 26/06/19 15:24:48 GMT FROM: marion.pillas(a)ligo.org A. Simon (TShNU of Kyiv), M. Mašek (FZU), N. Kochiashvili (AbAO), M. Pillas (IAP), D. Akl (NYUAD), R. Hanna (IJCLAB), P. Putsathan (KKU), Y. Rajabov (UBAI), S. Antier (IJCLAB), P. Hello (IJCLAB), M. Coughlin (UNM), S. Karpov (FZU), C. Douzet (IJCLAB), D. Rusanova (TShNU of Kyiv), V. Shynkarova (TShNU of Kyiv), A. Korosko (TShNU of Kyiv), 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), C. Limonta (OCA), A. Dupin (OCA), Q. André (OCA), M. Molham (NRIAG), E. Elhosseiny (NRIAG), A. Takey (NRIAG), T. Kvernadze (AbAO) on behalf of on GRANDMA collaboration: We continued our observations of the field of the Fermi Long GRB 260610B (Fermi GBM team, GCN 44901). The additional observations started on June 2026, 16 up to now. We still detect the optical afterglow using TTT-200cm, T150 at Abastumani Observatory, UBAI-AZT-22 at Madainak Observatory, AZT-8 at Lisnyky Observatory, KAO-1.88m at Kottamia Astronomical Observatory. We detect a re-brightening, which is consistent with other measurements reported in GCN 44955, GCN 44958, GCN 44959, GCN 44963, GCN 44993, 44999, 45003, 45004. 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. 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 (kilonovacatcher.in2p3.fr). Astrophysics Center for Multimessenger studies in Europe is supported Skyportal/ICARE (contact camille.douzet(a)ijclab.in2p3.fr, skyportal.io). The TTT Observing Time Rights (DTO) used were provided by Light Bridges, SL. View this GCN Circular online at https://gcn.nasa.gov/circulars/45007. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43221] GRB 260604B: 239Alferov CubeSat detection
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45006 SUBJECT: GRB 260604B: 239Alferov CubeSat detection DATE: 26/06/19 14:51:29 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> GRB 260604B: 239Alferov CubeSat detection D. Svinkin (Ioffe), D. Frederiks (Ioffe), D. Kapshtan (Geoscan), M. Orlov (Geoscan), V. Bazunova (Geoscan), E. Shchepin (Geoscan), E. Meltsov (Geoscan), K. Starikov (Geoscan, SPbSU), A. Khogoev (Geoscan), A. Razdobarin (SPbAU), and D. Dolmatov (SPbSU), on behalf of the 239Alferov team, report: The long-duration GRB 260604B (Fermi-GBM detection: The Fermi GBM team, GCN 44818; SVOM-GRM detection: Zhang et al., GCN 44850) was detected by 239Alferov 3U CubeSat at about 31555 s (08:45:55) UT. The burst was also detected by Konus-Wind in the waiting mode. The burst light curve, as measured by 239Alferov detector, shows a multi-peaked structure with a duration of ~8 s. The emission is seen up to ~500 keV. The light curve recorded by 239Alferov is available at: http://www.ioffe.ru/LEA/239Alferov/260604B/ 239Alferov GRB detections are listed at: http://www.ioffe.ru/LEA/239Alferov/ 239Alferov is an educational 3U CubeSat mission at SSO combining amateur radio and space research objectives. The gamma-ray detector onboard 239Alferov contains a 64x72x15 mm NaI(Tl) scintillator read out by a SiPM array and covers the energy range from ~20 keV to ~1000 keV. Currently, the instrument records count rates in five energy bands: ~20-50 keV, ~50-100 keV, ~100-500 keV, 500-1000 keV, and > 1000 keV, with 0.5 s temporal resolution. The ground segment of the mission utilizes the SONIKS open ground station network. View this GCN Circular online at https://gcn.nasa.gov/circulars/45006. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43220] GRB 260604A: 239Alferov CubeSat detection
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45005 SUBJECT: GRB 260604A: 239Alferov CubeSat detection DATE: 26/06/19 14:48:42 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> D. Svinkin (Ioffe), D. Frederiks (Ioffe), D. Kapshtan (Geoscan), M. Orlov (Geoscan), V. Bazunova (Geoscan), E. Shchepin (Geoscan), E. Meltsov (Geoscan), K. Starikov (Geoscan, SPbSU), A. Khogoev (Geoscan), A. Razdobarin (SPbAU), and D. Dolmatov (SPbSU), on behalf of the 239Alferov team, report: The long-duration GRB 260604A (Fermi-GBM detection: The Fermi GBM team, GCN 44812; Glowbug detection: Cheung et al., GCN 44845; SVOM-GRM detection: Yu et al., GCN 44863) was detected by 239Alferov 3U CubeSat at about 8668 s (02:24:28) UT. The burst was also detected by Konus-Wind in the waiting mode. The burst light curve, as measured by 239Alferov detector, shows a single pulse with a duration of ~5 s. The emission is seen up to ~500 keV. The light curve recorded by 239Alferov is available at: http://www.ioffe.ru/LEA/239Alferov/260604A/ 239Alferov GRB detections are listed at: http://www.ioffe.ru/LEA/239Alferov/ 239Alferov is an educational 3U CubeSat mission at SSO combining amateur radio and space research objectives. The gamma-ray detector onboard 239Alferov contains a 64x72x15 mm NaI(Tl) scintillator read out by a SiPM array and covers the energy range from ~20 keV to ~1000 keV. Currently, the instrument records count rates in five energy bands: ~20-50 keV, ~50-100 keV, ~100-500 keV, 500-1000 keV, and > 1000 keV, with 0.5 s temporal resolution. The ground segment of the mission utilizes the SONIKS open ground station network. View this GCN Circular online at https://gcn.nasa.gov/circulars/45005. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43219] GRB 260610B: VLT/FORS2 spectroscopic observation suggests the non-thermal nature of the optical rebrightening
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45004 SUBJECT: GRB 260610B: VLT/FORS2 spectroscopic observation suggests the non-thermal nature of the optical rebrightening DATE: 26/06/19 14:42:59 GMT FROM: Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo(a)ucd.ie> G. Corcoran (UCD), A. Martin-Carrillo (UCD), L. Izzo (INAF/OAC and DARK/NBI), J. An (NAOC), D. B. Malesani (DAWN/NBI and Radboud), B. P. Gompertz (Birmingham), A. J. Levan (Radboud and Warwick), A. de Ugarte Postigo (LAM), report on behalf of the Stargate collaboration: We performed spectroscopic observations of GRB 260610B discovered by Fermi (Fermi GBM team, GCN 44901; Godwin & Meegan GCN 44931) and SVOM (Yu et al., GCN 44944), whose optical afterglow has recently experienced an optical rebrightening (O’Neill et al., GCNs 44903, 44914; Watson et al., GCN 44905; Zhu et al., GCN 44909; Gillanders et al., GCNs 44910, 44955; Akl et al., GCNs 44911, 44930; Moskvitin et al., GCNs 44918, 44929; Jackson-Horne et al., GCN 44919; Izzo et al., GCN 44920; Li et al., GCN 44921; Bochenek et al., GCNs 44927, 44932; Pankov et al., GCN 44946; Angulo et al., GCN 44958; Moskvitin et al., GCN 44963; Pankov et al., GCN 44977; Gassert et al., GCN 44981; Gupta et al., GCN 44993). We used the ESO Very Large Telescope (VLT) UT1 (Antu) equipped with the FORS2 spectrograph with the 300V grism, covering the wavelength range 4400-8650 AA. The observation consisted of 4 exposures of 600 s each. The observation started at 00:41:19 UT on June 17 2026 (6.04 days after the GRB). In our acquisition image, we measured an AB magnitude r ~ 20 (calibrated against Pan-STARRS, not corrected for Galactic extinction). Based on the reported light curve, this seems to indicate that our observation occurred during the peak of this late flaring episode. The spectrum of the optical counterpart reveals a power-law continuum across the entire covered range suggesting that the observed recent activity is likely caused by late jet activity. Faint undulations are seen overimposed to the continuum, at a flux level consistent with the emergence of an early, still faint SN, but further observations will be required to conclude about its presence. Additionally, through the detection of the Ca II doublet in absorption and [O II] doublet in emission, we confirm the redshift reported by O’Neill et al. (GCN 44914), measuring z = 0.474. Further spectroscopic observations of the source are planned to monitor the possible emergence of the supernova. We acknowledge excellent support from the ESO observing staff in Paranal, in particular Martina Baratella and Leo Rivas, for rapidly executing these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/45004. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43218] GRB 260619A: SVOM/VT optical counterpart confirmation
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45003 SUBJECT: GRB 260619A: SVOM/VT optical counterpart confirmation DATE: 26/06/19 14:30:00 GMT FROM: Huali Li at at NAOC, SVOM <lhl(a)nao.cas.cn> H. L. Li, L. P. Xin, Y. L. Qiu, C. Wu, Y. N. Ma, Z. H. Yao, J. R. Xu, X. H. Han, J. Wang, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, J. S. Deng, J. Y. Wei (NAOC), J. Palmerio (CEA/Irfu), Kuan Liu (GXU), Zhiyong Liu (GZNU) report on behalf of the SVOM/VT team. SVOM/VT performed ToO observations of GRB260619A triggered by SVOM/ECLAIRs (sb26061901, Goto et al., GCN 44985). The observation started at 2026-06-19T05:54:32 UTC, approximately 3.71 hours post trigger in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously. The optical candidate (Ducoin et al., GCN 44999) was detected in both channels. The following measurements are in the AB magnitude and are not corrected for Galactic extinction: Mid time | Band | Exposure Time | Brightness 6.13 h VT_B 14*70 s 22.56 +/- 0.15 mag 6.14 h VT_R 13*70 s 22.63 +/- 0.18 mag 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. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/45003. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43217] GRB 260618B: SVOM/VT optical candidate
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45001 SUBJECT: GRB 260618B: SVOM/VT optical candidate DATE: 26/06/19 13:38:11 GMT FROM: Huali Li at at NAOC, SVOM <lhl(a)nao.cas.cn> H. L. Li, L. P. Xin, Y. L. Qiu, C. Wu, J. R. Xu, Y. N. Ma, Z. H. Yao, X. H. Han, J. Wang, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, J. S. Deng, J. Y. Wei (NAOC), J. T. Palmerio (CEA/Irfu) report on behalf of the SVOM/VT team. SVOM/VT performed ToO observations for GRB 260618B detected by Fermi-LAT (Gupta et al., GCN 44983) and Fermi-GBM (the Fermi GBM team, GCN 44979). The observation started at 2026-06-19T01:44:32 UTC, i.e., 8.83 hours post trigger in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously. An uncatalogued optical candidate was clearly detected in both channels compared with the Legacy Survey, with an angular separation of 8.7 arcminutes from the Fermi-LAT position (Gupta et al., GCN 44983). The position is at R.A., Dec. = 354.333559, -44.735518 degrees, equivalent to: R.A. (J2000) = 23:37:20.05 Dec. (J2000) = -44:44:07.87 with an uncertainty of 0.5 arcsec. The following measurements are in the AB magnitude and are not corrected for Galactic extinction: Mid time | Band | Exposure Time | Brightness 10.53 h VT_B 48*70 s 20.8 +/-0.1 mag 10.53 h VT_R 41*70 s 20.9 +/-0.1 mag 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. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/45001. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43216] Fermi-LAT Gamma-ray Observations of IceCube-260610A
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45002 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-260610A DATE: 26/06/19 14:05:43 GMT FROM: Leo Pfeiffer at University of Würzburg <pfeiffer.leo(a)gmail.com> L. Pfeiffer (Univ. of Wuerzburg), S. Buson (DESY, Univ. of Wuerzburg) and S. Garrappa (Weizmann Institute of Science) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC260610A neutrino event (GCN 44899) with all-sky survey data from the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. The IceCube event was detected on 26-06-10 at 20:02:41.03 UTC (T0) with J2000 position RA = 309.20 (+2.04, -2.06) deg, Decl. = 37.22 (+0.96/-0.93) deg 90% PSF containment. Two cataloged >100 MeV gamma-ray source are located within the 90% IC260610A localization error, at a distance of roughly 0.77 and 1.45 deg (4FGL-DR4; The Fourth Fermi-LAT catalog Data Release 4, The Fermi-LAT collaboration 2023, arXiv:2307.12546). These are the objects: 4FGL J2035.0+3632 associated with PSR J2034+3632. Based on a preliminary analysis of the LAT data over the timescale of 1-day and 1-month, this object is not significantly detected at gamma-rays. 4FGL J2030.0+3641 associated with PSR J2030+3641. Based on a preliminary analysis of the LAT data over the timescale of 1-day, this object is not significantly detected at gamma-rays. On a 1-month integration timescale prior to T0, it is detected significantly but the flux is in agreement with the average flux of the source reported in 4FGL-DR4. We conclude that the source is not in high state. We searched for the existence of intermediate (days to years) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (>5sigma) new excess emission (> 100 MeV) within the IC260610A 90% confidence localization. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC260610A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 2.7e-9 ph cm^-2 s^-1 for ~18-years (2008-08-04 / T0), <1.2e-08 (<2.6e-07) ph cm^-2 s^-1 for a 1-month (1-day) integration time before T0. Since Fermi normally operates in an all-sky scanning mode, regular monitoring of this source will continue. For this source the Fermi-LAT contact person is Leonard Pfeiffer (leonard.pfeiffer at uni-wuerzburg.de). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. View this GCN Circular online at https://gcn.nasa.gov/circulars/45002. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43215] GRB 260618B: SVOM/VT optical candidate
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 45000 SUBJECT: GRB 260618B: SVOM/VT optical candidate DATE: 26/06/19 13:04:05 GMT FROM: Huali Li at at NAOC, SVOM <lhl(a)nao.cas.cn> H. L. Li, L. P. Xin, Y. L. Qiu, C. Wu, J. R. Xu, Y. N. Ma, Z. H. Yao, X. H. Han, J. Wang, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, J. S. Deng, J. Y. Wei (NAOC), J. T. Palmerio (CEA/Irfu) report on behalf of the SVOM/VT team. SVOM/VT performed ToO observations for GRB 260618B detected by Fermi-LAT (Gupta et al., GCN 44983) and Fermi-GBM (the Fermi GBM team, GCN 44979). The observation started at 2026-06-19T01:44:32 UTC, i.e., 8.83 hours post trigger in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously. An uncatalogued optical candidate was clearly detected in both channels compared with the Legacy Survey, with an angular separation of 8.7 arcminutes from the Fermi-LAT position. The position is at R.A., Dec. = 240.862173, 50.563348 degrees, equivalent to: R.A. (J2000) = 16:03:26.92 Dec. (J2000) = +50:33:48.05 with an uncertainty of 0.5 arcsec. The following measurements are in the AB magnitude and are not corrected for Galactic extinction: Mid time | Band | Exposure Time | Brightness 10.53 h VT_B 48*70 s 20.8 +/-0.1 mag 10.53 h VT_R 41*70 s 20.9 +/-0.1 mag 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. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/45000. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43214] GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
by GCN Circulars 19 Jun '26

19 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44999 SUBJECT: GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate DATE: 26/06/19 13:01:35 GMT FROM: J.-G. Ducoin at CPPM <ducoin(a)cppm.in2p3.fr> Jean-Grégoire Ducoin (CPPM), Rosa L. Becerra (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Alan M. Watson (UNAM), Edilberto Aguilar-Ruiz (UNAM), Jean-Luc Atteia (IRAP), Camila Angulo (UNAM), Dalya Akl (NYUAD), Sarah Antier (IJCLAB), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Francis Fortin (IRAP), Leonardo García-García (UNAM), Ramandeep Gill (UNAM), Noémie Globus (UNAM), Marion Guelfand (CPPM), Asuka Kuwata (UNAM), Massimiliano Lincetto (CPPM), Nikos Mandarakas (LAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), Margarita Pereyra (UNAM), Fredd Sánchez Álvarez (UNAM), Benjamin Schneider (LAM), Antonio de Ugarte Postigo (LAM), Alan M. Watson (UNAM), Hatsune Goto (RIKEN), Jun Yang (ZZU), Kuan Liu (GXU), Zhiyong Liu (GZNU) report: We imaged the field of the SVOM GRB 260619A (Goto et al., GCN Circ. 44985) using the DDRAGO two-channel wide-field imager on the SVOM/COLIBRÍ (FM-GFT) telescope. We observed from 2026-06-19 09:49:05 to 11:11:49 UTC (from 7.62 to 9.01 hours after the trigger) and obtained 61 minutes of simultaneous exposure in the r and z filters. The data were reduced, coadded and analysed with the COLIBRÍ ASU pipeline and cross-analyzed with STDWeb/STDPipe (Karpov 2025). The photometry was calibrated using nearby stars from the PanSTARRS DR1 catalog, is in the AB system, and is not corrected for Galactic extinction. We detect an uncatalogued source (revealed by image subtraction using Legacy Survey) consistent with the ECLAIRs 11.33 arcmin error circle (Goto et al., GCN Circ. 44985) at: RA(J2000) = 23:56:24.46 = 359.10192 degrees Dec(J2000) = -15:27:41.0 = -15.46140 degrees with an uncertainty of 0.5 arcsec. The preliminary unsubtracted magnitude derived for that source is: r = 22.13 +/- 0.05 z = 21.91 +/- 0.14 The lack of clear evidence for variability, prevents a firm confirmation that this source is the optical afterglow of GRB 260619A. We thank the staff of the Observatorio Astronómico Nacional at Sierra de San Pedro Mártir, as well as the technical and engineering teams at CEA, CPPM, IRAP, LAM, OHP, OSU Pytheas, and UNAM. COLIBRÍ is an astronomical observatory developed and operated jointly by France (AMU, CNES and CNRS) and Mexico (UNAM and SECIHTI). It is located at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir, Baja California, Mexico. View this GCN Circular online at https://gcn.nasa.gov/circulars/44999. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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