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

[vsnet-grb-info 41589] EP260116a: COLIBRÍ further observations
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43491 SUBJECT: EP260116a: COLIBRÍ further observations DATE: 26/01/21 19:38:30 GMT FROM: Alan Watson at UNAM <alan(a)astro.unam.mx> Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Edilberto Aguilar-Ruiz (UNAM), Jean-Luc Atteia (IRAP), Camila Angulo (UNAM), Dalya Akl (NYUAD), Sarah Antier (IJCLAB), Rosa L. Becerra (UNAM), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Jean-Grégoire Ducoin (CPPM), Francis Fortin (IRAP), Leonardo García García (UNAM), Ramandeep Gill (UNAM), Noémie Globus (UNAM), Asuka Kuwata (UNAM), Nikos Mandarakas (LAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), Margarita Pereyra (UNAM), Ny Avo Rakotondrainibe (LAM), Fredd Sánchez Álvarez (UNAM), Benjamin Schneider (LAM) and Antonio de Ugarte Postigo (LAM) report: We observed the field of EP260116a (Wang et al., GCN Circ. 43424) with the DDRAGO two-channel wide-field imager on the COLIBRÍ telescope from 2026-01-21 03:47 to 07:39 UTC (from 123.6 to 127.5 hours after the trigger) and obtained 99 and 171 minutes of exposure in the r and z filters, respectively. The observing conditions were good. The data were reduced, coadded, calibrated, and analyzed with the COLIBRÍ ASU pipeline. The photometry was calibrated using nearby stars from the PanSTARRS DR1 catalog, is in the AB system, and is not corrected for Galactic extinction. The source we have previously reported (Butler et al., GCN Circ 43459; Watson et al., GCN Circ 43480) is clearly detected with preliminary magnitudes of r = 23.09 +/- 0.06, z = 23.10 +/- 0.13. Considering all of our data, the rebrightening we tentatively reported (Watson et al., GCN Circ 43480) is not confirmed and the data seem to be best explained by a simple flattening. We also note that while this source is within the WXT error regions, it is not within the FXT error region (Wang et al., GCN Circ. 43424). We do not consider it to be associated with EP 260116a. We thank the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir and the COLIBRÍ and DDRAGO engineering teams. 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/43491. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41588] GRB 251122A / EP251122a: VLT/X-shooter host redshift z = 1.765
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43490 SUBJECT: GRB 251122A / EP251122a: VLT/X-shooter host redshift z = 1.765 DATE: 26/01/21 17:54:30 GMT FROM: Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani(a)nbi.ku.dk> B. Schneider (LAM), A. Saccardi (CEA/Irfu), J. T. Palmerio (CEA/Irfu), S. D. Vergani (LUX-Paris Obs.), D. B. Malesani (DAWN/NBI and Radboud), M. Ferro (INAF/OAB), G. Corcoran (UCD), C. Lachaud (APC), Z.-Y. Lin (APC), report on behalf of the Stargate collaboration: At the position of the optical counterpart (Cheng et al., GCN 42803; Li et al., GCN 42806; Sun et al., GCN 42807; Ma et al., GCN 42811; Gupta et al., GCN 42813; Busman et al., GCN 42814; Volnova et al., GCN 42950) of the high-energy transient GRB 251122A / EP251122a (Wang et al., GCN 42799; Lin et al., GCN 42800), a galaxy is visible in the Legacy survey, with magnitude r ~ 24.6, which is also detected in archival images from the Hyper Suprime-Cam Legacy Archive (Tanaka et al. 2021, doi:10.1093/pasj/psab034) A spectrum of this object was secured using the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph. The spectrum covers the wavelength range 3000-25000 AA, and consists of 4 exposures of 1200 s each. The observation mid time is 2025 Dec 23.08 UT (30.5 days after the GRB). A single, very clear emission line is detected at 18140 Å. We discuss its interpretation below. - At the X-shooter resolution we would expect to resolve it if it was the [O II] 3727/3729 doublet (at z = 3.87). While the line is indeed resolved in wavelength space, it does not show a doublet profile; there is also no hint of Lyalpha nor [O III] 5008 in emission at this redshift. - The line cannot be [O III] 5008 (at z = 2.62), otherwise we would also detect [O III] 4959, which is expected from first principles to be ~1/3 as intense, and is excluded by our data. We also do not detect Halpha in the K band, a region clean of atmospheric absorption. - The line is however consistent with Halpha at z = 1.765; at this redshift, both Hbeta and [O III] fall at observed wavelengths with poor atmospheric transmission, and their non-detection is thus not unexpected. The [O II] doublet is not detected at this redshift, although it falls in a noisy region of the spectrum (at the interface between the X-shooter VIS and NIR arms). Dust extinction could also contribute to the faintness of this line. We conclude that z = 1.765 is most likely the redshift of GRB 251122A / EP251122a. We acknowledge excellent support from the observing staff at Paranal, in particular Claudia Cid, Florian Rodler, Jonathan Smoker and Thomas Rivinius. The analysis of this spectrum was carried out with the help of the zHunter tool (https://doi.org/10.5281/zenodo.15189495) View this GCN Circular online at https://gcn.nasa.gov/circulars/43490. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41587] GRB 260120B: Fermi GBM Observation
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43489 SUBJECT: GRB 260120B: Fermi GBM Observation DATE: 26/01/21 16:21:32 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 18:00:26.05 UT on 20 January 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260120B (trigger 790624831/260120750), which was also detected by Swift BAT (Ferro et al. 2026, GCN 43479), Swift XRT (Goad et al. 2026, GCN 43484), and SVOM/C-GFT (Wu et al. 2026, GCN 43483). The Fermi GBM real-time localization (GCN 43477) is consistent with the Swift BAT position. The angle from the Fermi LAT boresight is 10 degrees. The GBM light curve consists of a single emission episode with a duration (T90) of about 7 s (50-300 keV). The time-averaged spectrum from T0-1.1 to T0+9.9 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.19 +/- 0.01 and the cutoff energy, parameterized as Epeak, is 214 +/- 4 keV. The event fluence (10-1000 keV) in this time interval is (3.1 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.38 s in the 10-1000 keV band is 5.8 +/- 0.3 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 152 +/- 2 keV, alpha = 0.36 +/- 0.02 and beta = -2.26 +/- 0.05. 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/43489. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41586] EP260105a: GTC/HiPERCAM optical observations
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43488 SUBJECT: EP260105a: GTC/HiPERCAM optical observations DATE: 26/01/21 16:05:28 GMT FROM: javisansie(a)gmail.com J. Sanchez-Sierras (Radboud), G. Corcoran (UCD), P. G. Jonker (Radboud), D. B. Malesani (DAWN/NBI and Radboud), D. Mata Sanchez (IAC), A. L. Cabrera Lavers (GTC), report on behalf of a larger collaboration: We observed the field of EP260105a (Zhou et al., GCN 43327) with the HiPERCAM instrument attached to the Gran Telescopio Canarias (GTC; La Palma, Spain). The observation simultaneously covered the u, g, r, i and z bands with a total exposure time of 1612 s (150 x 10.75 s), starting on 2026-01-15 at 05:49:40 UT (i.e. 10 days after the trigger). Several sources are detected within the EP/FXT error circle, but comparison with archival i-band imaging from the Hyper Suprime-Cam Legacy Archive (Tanaka et al. 2021, doi:10.1093/pasj/psab034) shows all of them to be pre-existing. We carried out subtraction in the i-band with PyZOGY (Guevel et al. 2021), using the HSC image as a template. The subtraction does not show any new source inside the EP-FXT error region (Zhou et al., GCN 43333) down to a limiting AB magnitude of i > 25.5, not corrected by Galactic extinction. This non-detection is consistent with the others reported by Lipunov et al. (GCN 43328), Corcoran et al. (GCN 43332), Li et al. (GCN 43337) and Busmann et al. (GCN 43345). View this GCN Circular online at https://gcn.nasa.gov/circulars/43488. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41585] EP260105a: GTC/HiPERCAM optical observations
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43488 SUBJECT: EP260105a: GTC/HiPERCAM optical observations DATE: 26/01/21 16:05:28 GMT FROM: javisansie(a)gmail.com J. Sanchez-Sierras (Radboud), G. Corcoran (UCD), P. G. Jonker (Radboud), D. B. Malesani (DAWN/NBI and Radboud), D. Mata Sanchez (IAC), A. L. Cabrera Lavers (GTC), report on behalf of a larger collaboration: We observed the field of EP260105a (Zhou et al., GCN 43327) with the HiPERCAM instrument attached to the Gran Telescopio Canarias (GTC; La Palma, Spain). The observation simultaneously covered the u, g, r, i and z bands with a total exposure time of 1612 s (150 x 10.75 s), starting on 2026-01-15 at 05:49:40 UT (i.e. 10 days after the trigger). Several sources are detected within the EP/FXT error circle, but comparison with archival i-band imaging from the Hyper Suprime-Cam Legacy Archive (Tanaka et al. 2021, doi:10.1093/pasj/psab034) shows all of them to be pre-existing. We carried out subtraction in the i-band with PyZOGY (Guevel et al. 2021), using the HSC image as a template. The subtraction does not show any new source inside the EP-FXT error region (Zhou et al., GCN 43333) down to a limiting AB magnitude of i > 25.5, not corrected by Galactic extinction. This non-detection is consistent with the others reported by Lipunov et al. (GCN 43328), Corcoran et al. (GCN 43332), Li et al. (GCN 43337) and Busmann et al. (GCN 43345). View this GCN Circular online at https://gcn.nasa.gov/circulars/43488. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41584] GRB 260120B: Swift/UVOT Detection
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43487 SUBJECT: GRB 260120B: Swift/UVOT Detection DATE: 26/01/21 14:04:46 GMT FROM: Alice Breeveld at MSSL-UCL <a.breeveld(a)ucl.ac.uk> A.A. Breeveld (UCL-MSSL) and M. Ferro (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 260120B 149 s after the BAT trigger (Ferro et al., GCN Circ. 43479). A fading source consistent with the optical counterpart position given by Wu et al., (GCN Circ. 43483) and also the enhanced XRT position (Goad et al., GCN Circ. 43484) is detected in the initial UVOT exposures. Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 149 299 147 18.38 ± 0.06 white 588 776 35 >19.4 v 637 657 19 >17.4 b 563 755 39 >18.7 u 307 557 246 18.80 ± 0.14 w1 686 705 19 >17.4 m2 661 681 19 >17.1 w2 613 633 19 >17.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.063 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/43487. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41583] GRB 260120B: COLIBRÍ optical upper limits
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43486 SUBJECT: GRB 260120B: COLIBRÍ optical upper limits DATE: 26/01/21 03:39:32 GMT FROM: globus(a)astro.unam.mx Noémie Globus (UNAM), Antonio de Ugarte Postigo (LAM), Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Edilberto Aguilar-Ruiz (UNAM), Jean-Luc Atteia (IRAP), Camila Angulo (UNAM), Dalya Akl (NYUAD), Sarah Antier (IJCLAB), Rosa L. Becerra (UNAM), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Jean-Grégoire Ducoin (CPPM), Francis Fortin (IRAP), Leonardo García García (UNAM), Ramandeep Gill (UNAM), Asuka Kuwata (UNAM), Nikos Mandarakas (LAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), Margarita Pereyra (UNAM), Ny Avo Rakotondrainibe (LAM), Fredd Sánchez Álvarez (UNAM), and Benjamin Schneider (LAM): We imaged the field of the Swift GRB 260120B (Ferro at al., GCN Circ. 43479; Goad et al., GCN Circ. 43484), also detected by Fermi (Fermi GBM team, GCN Circ. 43477) using the DDRAGO two-channel wide-field imager on the COLIBRÍ telescope. We observed from 2026-01-21 02:00 to 02:19 UTC (from 8.01 to 8.31 hours after the trigger) and obtained 16 minutes of simultaneous exposure in the r and z filters during evening twilight. The data were reduced and coadded with the COLIBRÍ ASU pipeline. 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 do not detect any source within the enhanced XRT error circle (Goad et al., GCN Circ 43484) down to the following 3-sigma limits: r > 22.87, z > 22.12. We do not detect the afterglow candidate reported by Wu et al (GCN Circ. 43483). This is consistent with the source having faded below our detection limit by the time of our observation, and indicates a temporal index steeper than -1.0. We thank the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir and the COLIBRÍ and DDRAGO engineering teams. 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/43486. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41582] SVOM GRB260121.06: Global MASTER-Net observations report
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43485 SUBJECT: SVOM GRB260121.06: Global MASTER-Net observations report DATE: 26/01/21 02:56:37 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-SAAO robotic telescope [1] located in South Africa (South African Astronomical Observatory) started inspect of the SVOM GRB260121.06 (trigger No 1768959043,10h 09m 06.72s , +04d 48m 17.6s, R=1) errorbox 28 sec after notice time and 143 sec after trigger time at 2026-01-21 01:33:06 UT, with upper limit up to 19.7 mag. The observations began at zenith distance = 38 deg. The sun altitude is -24.9 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) started inspect of the SVOM GRB260121.06 errorbox 1707 sec after notice time and 1822 sec after trigger time at 2026-01-21 02:01:05 UT, with upper limit up to 19.9 mag. The observations began at zenith distance = 76 deg. The sun altitude is -25.5 deg. The galactic latitude b = 46 deg., longitude l = 236 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3110313 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 159 | 2026-01-21 01:33:06 | MASTER-SAAO | (10h 07m 16.32s , +04d 43m 38.5s) | C | 30 | 19.2 | 159 | 2026-01-21 01:33:06 | MASTER-SAAO | (10h 05m 27.00s , +04d 59m 33.9s) | C | 30 | 19.0 | 213 | 2026-01-21 01:33:55 | MASTER-SAAO | (10h 07m 16.37s , +04d 43m 40.6s) | C | 40 | 19.3 | 213 | 2026-01-21 01:33:55 | MASTER-SAAO | (10h 05m 27.09s , +04d 59m 36.5s) | C | 40 | 19.2 | 277 | 2026-01-21 01:34:54 | MASTER-SAAO | (10h 07m 16.48s , +04d 43m 42.9s) | C | 50 | 19.6 | 277 | 2026-01-21 01:34:54 | MASTER-SAAO | (10h 05m 27.21s , +04d 59m 39.0s) | C | 50 | 19.4 | 351 | 2026-01-21 01:36:03 | MASTER-SAAO | (10h 07m 16.52s , +04d 43m 45.3s) | C | 60 | 19.6 | 351 | 2026-01-21 01:36:03 | MASTER-SAAO | (10h 05m 27.32s , +04d 59m 41.6s) | C | 60 | 19.6 | 430 | 2026-01-21 01:37:22 | MASTER-SAAO | (10h 07m 16.50s , +04d 43m 47.8s) | C | 60 | 19.7 | 430 | 2026-01-21 01:37:23 | MASTER-SAAO | (10h 05m 27.44s , +04d 59m 44.2s) | C | 60 | 19.6 | 509 | 2026-01-21 01:38:41 | MASTER-SAAO | (10h 07m 16.66s , +04d 43m 50.7s) | C | 60 | 19.7 | 509 | 2026-01-21 01:38:41 | MASTER-SAAO | (10h 05m 27.61s , +04d 59m 47.4s) | C | 60 | 19.6 | 588 | 2026-01-21 01:40:00 | MASTER-SAAO | (10h 07m 16.81s , +04d 43m 53.2s) | C | 60 | 19.7 | 588 | 2026-01-21 01:40:00 | MASTER-SAAO | (10h 05m 27.77s , +04d 59m 50.0s) | C | 60 | 19.5 | 667 | 2026-01-21 01:41:20 | MASTER-SAAO | (10h 07m 16.96s , +04d 43m 55.6s) | C | 60 | 19.5 | 667 | 2026-01-21 01:41:20 | MASTER-SAAO | (10h 05m 27.93s , +04d 59m 52.5s) | C | 60 | 19.5 | 746 | 2026-01-21 01:42:39 | MASTER-SAAO | (10h 07m 17.14s , +04d 43m 58.4s) | C | 60 | 19.7 | 746 | 2026-01-21 01:42:39 | MASTER-SAAO | (10h 05m 28.11s , +04d 59m 55.5s) | C | 60 | 19.6 | 825 | 2026-01-21 01:43:58 | MASTER-SAAO | (10h 07m 17.17s , +04d 44m 00.9s) | C | 60 | 19.6 | 825 | 2026-01-21 01:43:58 | MASTER-SAAO | (10h 05m 28.27s , +04d 59m 58.2s) | C | 60 | 19.5 | 904 | 2026-01-21 01:45:17 | MASTER-SAAO | (10h 07m 17.19s , +04d 44m 03.4s) | C | 60 | 19.6 | 904 | 2026-01-21 01:45:17 | MASTER-SAAO | (10h 05m 28.40s , +05d 00m 00.9s) | C | 60 | 19.6 | 983 | 2026-01-21 01:46:36 | MASTER-SAAO | (10h 07m 17.39s , +04d 44m 05.8s) | C | 60 | 19.6 | 983 | 2026-01-21 01:46:36 | MASTER-SAAO | (10h 05m 28.59s , +05d 00m 03.4s) | C | 60 | 19.5 | 1062 | 2026-01-21 01:47:55 | MASTER-SAAO | (10h 07m 17.56s , +04d 44m 08.7s) | C | 60 | 19.7 | 1062 | 2026-01-21 01:47:55 | MASTER-SAAO | (10h 05m 28.76s , +05d 00m 06.5s) | C | 60 | 19.6 | 1142 | 2026-01-21 01:49:14 | MASTER-SAAO | (10h 07m 17.74s , +04d 44m 11.1s) | C | 60 | 19.6 | 1142 | 2026-01-21 01:49:14 | MASTER-SAAO | (10h 05m 28.95s , +05d 00m 08.9s) | C | 60 | 19.5 | 1221 | 2026-01-21 01:50:33 | MASTER-SAAO | (10h 07m 17.92s , +04d 44m 13.6s) | C | 60 | 19.7 | 1221 | 2026-01-21 01:50:33 | MASTER-SAAO | (10h 05m 29.13s , +05d 00m 11.3s) | C | 60 | 19.5 | 1300 | 2026-01-21 01:51:52 | MASTER-SAAO | (10h 07m 18.11s , +04d 44m 16.4s) | C | 60 | 19.6 | 1300 | 2026-01-21 01:51:52 | MASTER-SAAO | (10h 05m 29.32s , +05d 00m 14.0s) | C | 60 | 19.5 | 1379 | 2026-01-21 01:53:11 | MASTER-SAAO | (10h 07m 17.98s , +04d 44m 19.0s) | C | 60 | 19.6 | 1379 | 2026-01-21 01:53:11 | MASTER-SAAO | (10h 05m 29.44s , +05d 00m 16.7s) | C | 60 | 19.5 | 1458 | 2026-01-21 01:54:31 | MASTER-SAAO | (10h 07m 18.15s , +04d 44m 21.6s) | C | 60 | 19.6 | 1458 | 2026-01-21 01:54:31 | MASTER-SAAO | (10h 05m 29.62s , +05d 00m 19.6s) | C | 60 | 19.5 | 1537 | 2026-01-21 01:55:49 | MASTER-SAAO | (10h 07m 18.33s , +04d 44m 24.5s) | C | 60 | 19.7 | 1537 | 2026-01-21 01:55:49 | MASTER-SAAO | (10h 05m 29.81s , +05d 00m 22.7s) | C | 60 | 19.6 | 1616 | 2026-01-21 01:57:08 | MASTER-SAAO | (10h 05m 29.97s , +05d 00m 24.8s) | C | 60 | 19.6 | 1852 | 2026-01-21 02:01:05 | MASTER-OAFA | (10h 09m 19.08s , +04d 45m 04.6s) | C | 60 | 14.8 | 1918 | 2026-01-21 02:02:10 | MASTER-OAFA | (10h 09m 19.20s , +04d 45m 08.9s) | C | 60 | 14.5 | 1984 | 2026-01-21 02:03:17 | MASTER-OAFA | (10h 09m 19.35s , +04d 45m 14.0s) | C | 60 | 14.8 | 2182 | 2026-01-21 02:06:35 | MASTER-OAFA | (10h 09m 19.86s , +04d 45m 30.4s) | C | 60 | 14.8 | 2248 | 2026-01-21 02:07:40 | MASTER-OAFA | (10h 09m 20.05s , +04d 45m 36.7s) | C | 60 | 14.2 | 2313 | 2026-01-21 02:08:46 | MASTER-OAFA | (10h 09m 20.21s , +04d 45m 41.4s) | C | 60 | 15.6 | 2379 | 2026-01-21 02:09:52 | MASTER-OAFA | (10h 09m 20.36s , +04d 45m 46.1s) | C | 60 | 17.2 | 2445 | 2026-01-21 02:10:57 | MASTER-OAFA | (10h 09m 20.47s , +04d 45m 50.5s) | C | 60 | 16.1 | 2511 | 2026-01-21 02:12:03 | MASTER-OAFA | (10h 09m 20.62s , +04d 45m 55.5s) | C | 60 | 13.3 | 2577 | 2026-01-21 02:13:10 | MASTER-OAFA | (10h 09m 20.79s , +04d 46m 01.4s) | C | 60 | 14.9 | 2643 | 2026-01-21 02:14:16 | MASTER-OAFA | (10h 09m 20.87s , +04d 46m 05.5s) | C | 60 | 13.5 | 2840 | 2026-01-21 02:17:32 | MASTER-OAFA | (10h 09m 21.35s , +04d 46m 21.7s) | C | 60 | 14.4 | 3103 | 2026-01-21 02:21:56 | MASTER-OAFA | (10h 09m 21.91s , +04d 46m 40.3s) | C | 60 | 14.9 | 3234 | 2026-01-21 02:24:07 | MASTER-OAFA | (10h 09m 22.15s , +04d 46m 50.2s) | C | 60 | 15.4 | 3300 | 2026-01-21 02:25:12 | MASTER-OAFA | (10h 09m 22.25s , +04d 46m 54.4s) | C | 60 | 17.2 | 3366 | 2026-01-21 02:26:19 | MASTER-OAFA | (10h 09m 22.36s , +04d 46m 59.7s) | C | 60 | 16.6 | 3432 | 2026-01-21 02:27:24 | MASTER-OAFA | (10h 09m 22.43s , +04d 47m 03.4s) | C | 60 | 17.1 | 3498 | 2026-01-21 02:28:30 | MASTER-OAFA | (10h 09m 22.54s , +04d 47m 06.7s) | C | 60 | 15.5 | 3629 | 2026-01-21 02:30:42 | MASTER-OAFA | (10h 09m 22.83s , +04d 47m 18.1s) | C | 60 | 17.1 | 3695 | 2026-01-21 02:31:47 | MASTER-OAFA | (10h 09m 22.90s , +04d 47m 21.4s) | C | 60 | 19.1 | 3760 | 2026-01-21 02:32:53 | MASTER-OAFA | (10h 09m 23.01s , +04d 47m 25.9s) | C | 60 | 18.8 | 3826 | 2026-01-21 02:33:59 | MASTER-OAFA | (10h 09m 23.12s , +04d 47m 30.8s) | C | 60 | 19.1 | 3892 | 2026-01-21 02:35:04 | MASTER-OAFA | (10h 09m 23.23s , +04d 47m 35.2s) | C | 60 | 19.1 | 3958 | 2026-01-21 02:36:11 | MASTER-OAFA | (10h 09m 23.30s , +04d 47m 39.2s) | C | 60 | 19.6 | 4024 | 2026-01-21 02:37:17 | MASTER-OAFA | (10h 09m 23.40s , +04d 47m 43.3s) | C | 60 | 19.4 | 4089 | 2026-01-21 02:38:22 | MASTER-OAFA | (10h 09m 23.48s , +04d 47m 47.2s) | C | 60 | 18.1 | 4156 | 2026-01-21 02:39:28 | MASTER-OAFA | (10h 09m 23.54s , +04d 47m 50.6s) | C | 60 | 15.0 | 4222 | 2026-01-21 02:40:34 | MASTER-OAFA | (10h 09m 23.68s , +04d 47m 56.6s) | C | 60 | 19.3 | 4288 | 2026-01-21 02:41:40 | MASTER-OAFA | (10h 09m 23.74s , +04d 48m 00.0s) | C | 60 | 19.8 | 4354 | 2026-01-21 02:42:46 | MASTER-OAFA | (10h 09m 23.82s , +04d 48m 03.9s) | C | 60 | 19.9 | 4419 | 2026-01-21 02:43:52 | MASTER-OAFA | (10h 09m 23.88s , +04d 48m 07.9s) | C | 60 | 19.8 | 4485 | 2026-01-21 02:44:57 | MASTER-OAFA | (10h 09m 23.96s , +04d 48m 11.7s) | C | 60 | 18.9 | 4551 | 2026-01-21 02:46:03 | MASTER-OAFA | (10h 09m 24.01s , +04d 48m 15.3s) | C | 60 | 18.6 | 4616 | 2026-01-21 02:47:09 | MASTER-OAFA | (10h 09m 24.08s , +04d 48m 19.3s) | C | 60 | 18.8 | 4682 | 2026-01-21 02:48:15 | MASTER-OAFA | (10h 09m 24.14s , +04d 48m 22.9s) | C | 60 | 18.9 | 4750 | 2026-01-21 02:49:22 | MASTER-OAFA | (10h 09m 24.22s , +04d 48m 26.6s) | C | 60 | 19.0 | 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/43485. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41581] GRB 260120B: Enhanced Swift-XRT position
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43484 SUBJECT: GRB 260120B: Enhanced Swift-XRT position DATE: 26/01/21 01:28:46 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 609 s of XRT Photon Counting mode data and 1 UVOT images for GRB 260120B, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 284.65977, +61.90497 which is equivalent to: RA (J2000): 18h 58m 38.34s Dec (J2000): +61d 54' 17.9" with an uncertainty of 2.3 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at https://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/43484. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 41580] GRB 260120B: SVOM/C-GFT optical counterpart detection
by GCN Circulars 21 Jan '26

21 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43483 SUBJECT: GRB 260120B: SVOM/C-GFT optical counterpart detection DATE: 26/01/21 01:08:29 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> C. Wu (NAOC), Z. Kang (CHO), L.P. Xin, X.H. Han, P.P. Zhang, X.M. Lu (NAOC), Z.W. Li, Y. Lv (CHO), R.S. Zhang, Y.J. Xiao, Y.L. Qiu, J. Wang, J.S. Deng, L. Huang, J.Y. Wei (NAOC) report on behalf of the SVOM/C-GFT team: We observed the field of GRB 260120B detected by Fermi/GBM(Fermi GBM team, GCN 43477) and Swift/BAT (Ferro et al., GCN 43479) with LATIOS on SVOM/C-GFT. Observa-tions started at 2026-01-20T18:01:29 UTC, ~63 seconds after the trigger. An uncatalogued optical source, compared to Legacy Surveys DR10 Source Catalog, is detected in our images within the localization error circle (Ferro et al., GCN 43479) at: RA (J2000) = 18h58m38.35s = 284.65980 degrees Dec (J2000) = +61d54m18s = 61.90508 degrees with an uncertainty of ~0.5 arcsec. The magnitudes are: | Mid_t-T0(s) | exposure time (s) | band | mag (AB) | mag_err| |-------------|-------------------|------|----------|--------| | 68 | 1x10 | i | 15.74 | 0.04 | | 634 | 6x30 | g | 19.18 | 0.12 | | 854 | 6x30 | r | 19.03 | 0.12 | The brightness decays very rapidly, with the source fading by ~3.4 mag in the i band over 1000 s starting at T0+68 s. The photometry was calibrated against nearby stars in UCAC4 catalogue and no correction for Galactic dust extinction was applied. We thank the observation assistants Hong-Xv Xue and Bo-Wen Li at Jilin observatory for their excellent support. The Chinese Ground Follow-up Telescope (C-GFT) for the SVOM mission is located at Jilin Station, Changchun Observatory, National Astronomical Observatories, CAS. It features two instruments: (1) CATCH at the Cassegrain focus with a 21 arcsec x 21 arcsec FOV for simultaneous g/r/i-band imaging, and (2) LATIOS, a 4k x 4k CMOS camera at the prime focus with a 1.28 deg x 1.28 deg FOV that images in g, r, and i bands via filter switching. View this GCN Circular online at https://gcn.nasa.gov/circulars/43483. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0