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

[vsnet-grb-info 41969] GRB 260226A : GROWTH-India Telescope optical observations
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43853 SUBJECT: GRB 260226A : GROWTH-India Telescope optical observations DATE: 26/02/26 19:55:15 GMT FROM: V. Swain at IIT Bombay <vishwajeet.s(a)iitb.ac.in> A.P. Saikia, V. Vijaykumar, T. Mohan, A. Devaraj, S. Patil, V. Swain, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team: We observed the field of Fermi GRB 260226A (Fermi GBM team, GCN 43840) also detected by Fermi LAT (Depalo et al., GCN 43844, 43850), with 0.7m GROWTH-India Telescope (GIT). The observations started at 2026-02-26 14:33:34 UT, i.e 3.9 hours after the GBM trigger. We tiled the LAT localization region, observed the field at a position angle of approximately 45 degrees, and covered about 74% of the localization area. No new transients were detected within the observed region. Each exposure was taken in the r′ filter with an exposure time of 300 seconds. The photometric results are summarized below: Tile Number | Tmid - T0 (hours) | RA (deg) | Dec (deg) |Upper limit (5 sigma)(AB) | | ------------ | ------ | --------------- | ------------------------- | -------------- | | 1 | 3.95 | 42.05 | 8.033 | 19.7 | | 2 | 4.03 | 41.83 | 7.713 | 19.6 | | 3 | 4.12 | 41.83 | 7.873 | 19.9 | | 4 | 4.21 | 41.83 | 8.033 | 19.8 | | 5 | 4.30 | 41.83 | 8.193 | 19.6 | | 6 | 4.39 | 41.83 | 8.353 | 19.7 | | 7 | 4.47 | 41.94 | 7.713 | 19.6 | | 8 | 4.56 | 41.94 | 7.873 | 19.7 | | 9 | 4.65 | 41.94 | 8.033 | 19.6 | | 10 | 4.75 | 41.94 | 8.193 | 19.5 | | 11 | 4.84 | 41.94 | 8.353 | 19.6 | | 12 | 4.93 | 42.05 | 7.713 | 19.4 | | 13 | 5.02 | 42.05 | 7.873 | 19.2 | | 14 | 5.10 | 42.05 | 8.193 | 19.3 | | 15 | 5.19 | 42.05 | 8.353 | 19.2 | | 16 | 5.28 | 42.16 | 7.873 | 19.0 | The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. Our results are consistent with other optical non-detections (Lipunov et al., GCN 43847,43848, Konno et al., 43852) The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 8' x 11' field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/. View this GCN Circular online at https://gcn.nasa.gov/circulars/43853. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41968] GRB 260226A: LAST optical upper limit
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43852 SUBJECT: GRB 260226A: LAST optical upper limit DATE: 26/02/26 19:42:00 GMT FROM: Ruslan Konno at Weizmann Institute of Science <ruslankonno(a)gmail.com> R. Konno (WIS), S. Garrappa (WIS), E. A. Zimmerman (WIS), A. Horowicz (WIS), E. O. Ofek (WIS), S. Ben-Ami (WIS), D. Polishook (WIS), O. Yaron (WIS), S. Fainer (WIS), A. Krassilchtchikov (WIS), Y. M. Shani (WIS), E. Segre (WIS), A. Gal-Yam (WIS), and S. Spitzer (WIS) report on behalf of the LAST Collaboration. We report observations of GRB 260226A, reported by Fermi-GBM (Fermi GBM Team, GCN 43840), as well as by Fermi-LAT (Depalo et al, GCN 43844) and AstroSat CZTI (Harsha et al, GCN 43846). Observations were conducted with the Large Array Survey Telescope (LAST; Ofek et al. 2023, PASP 135, 5001; Ben-Ami et al. 2023, PASP 135, 5002). Observations of GRB 260226A were taken over 10 sequential epochs in clear band (similar to the Gaia Bp band) with 4 telescopes simultaneously. The first epoch began at 2026-02-26 16:30:51UTC (T-T0 = 5.88 h). Each epoch consists of 20x20s exposures per telescope. We coadd a total of 4x120x20s (mid. T-T0=6.67 h) exposure images and perform image subtraction using a reference image of the field. We do not detect any clear new optical source up to a 5-sigma limiting magnitude of 20.15 (AB) within the error region reported in Bissaldi et al., GCN 43851. Performing image subtraction between the latest (mid. T-T0 = 7.31 h) and earliest (mid. T-T0 = 5.94 h) 20x20s exposure images also shows no source brighter than 19.4 mag decaying by more than 0.5 mag. Our results are consistent with other optical non-detections (Lipunov et al., GCN 43847,43848). LAST is a survey telescope array of the Weizmann Astrophysical Observatory (https://www.weizmann.ac.il/wao/) View this GCN Circular online at https://gcn.nasa.gov/circulars/43852. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41967] GRB 260226A: Fermi GBM observation
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43851 SUBJECT: GRB 260226A: Fermi GBM observation DATE: 26/02/26 16:21:05 GMT FROM: Elisabetta Bissaldi at Politecnico and INFN Bari <elisabetta.bissaldi(a)ba.infn.it> E. Bissaldi (Politecnico and INFN Bari), O.J. Roberts (Uni. of Galway, Ireland), P. Veres (UAH) and A. von Kienlin (MPE) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 10:39:05 UT on 26 February 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260226A (trigger 793795080/260226443), which was also detected by Fermi-LAT (Depalo et al. 2026, GCN 43844 and 43850) and AstroSat CZTI (Harsha et al. 2026, GCN 43846). The Fermi GBM on-ground location (GCN 43840) is consistent with the Fermi-LAT position. The angle from the Fermi LAT boresight is 26 degrees. The GBM light curve consists of a very bright and structured emission episode with a duration (T90) of about 82 s (50-300 keV). The time-averaged spectrum from T0 to T0+81 s is best fit by a Band function with Epeak = 723 +/- 8 keV, alpha = -0.95 +/- 0.01, and beta = -2.47 +/- 0.02. The event fluence (10-1000 keV) in this time interval is (4.54 +/- 0.01)E-04 erg/cm^2. The 1-sec peak photon flux measured starting from T0+19.3 s in the 10-1000 keV band is 166 +/- 2 ph/s/cm^2. 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/43851. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41966] GRB 260226A: Fermi-LAT refined analysis
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43850 SUBJECT: GRB 260226A: Fermi-LAT refined analysis DATE: 26/02/26 16:15:30 GMT FROM: Davide Depalo at Politecnico and INFN Bari <davide.depalo(a)ba.infn.it> D. Depalo (Politecnico and INFN Bari), E. Bissaldi (Politecnico and INFN Bari), A. Holzmann Airasca (UniTrento and INFN Bari), R. Gupta (NASA/GSFC), F. Longo (University and INFN, Trieste), S. Lopez (CNRS / IN2P3), R. Martinelli (University and INFN, Trieste), and J. L. Racusin (NASA/GSFC) report on behalf of the Fermi-LAT team: At 10:38:18.84 UT on Feb 26th, 2026 Fermi-LAT triggered and detected high-energy emission from GRB 260226A (Depalo et al., GCN Circular 43844), which was also detected by Fermi-GBM (trigger 793795080 / 260226443, GCN Circular 43840) and Astrosat (Harsha et al., GCN Circular 43846). The best LAT on-ground location is found to be RA, Dec = 41.93, 7.73 (J2000) with an error radius of 0.11 deg (90 % containment, statistical error only). This was 26 deg from the LAT boresight at the time of the trigger. The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance. The photon flux above 100 MeV in the time interval 0 - 1.5 ks after the GBM trigger is (1.50 ± 0.06)E-4 ph/cm2/s. The estimated photon index above 100 MeV is -3.25 ± 0.08. The highest energy photon has an energy of 1.1 GeV and occurs at 420 s after trigger time. The Fermi-LAT point of contact for this burst is Niccolò Di Lalla (niccolo.dilalla(a)stanford.edu) 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/43850. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41965] The EP-WXT trigger 01709258652 is likely a flaring star
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43849 SUBJECT: The EP-WXT trigger 01709258652 is likely a flaring star DATE: 26/02/26 16:09:54 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Guojiong Yang, Tong Zhao(Nao, CAS), Zecheng Zou(NJU) and Wenda Zhang(Nao, CAS) on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709258652 at the time of 2026-02-26T13:49:59(UTC), is likely a stellar flare associated with LP 435-538. The WXT position of the source is R.A. = 190.202 deg, DEC = 19.917 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). The estimated flux of the flare is around 8e-11 erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 2.071e+31 erg/s. A follow-up observation with the Follow-up X-ray Telescope (FXT) was performed automatically. An onboard alert was generated by FXT during this observation and the FXT position is R.A. = 190.1724 deg, DEC = 19.9231 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic). The FXT position is consistent with the star LP 435-538. 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/43849. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41964] LAT GRB260226.44: Global MASTER-Net observations report
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43848 SUBJECT: LAT GRB260226.44: Global MASTER-Net observations report DATE: 26/02/26 15:44:21 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-Tunka robotic telescope [1] located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the LAT GRB260226.44 (trigger No 793795080,02h 47m 41.04s , +07d 43m 12.0s, R=0.105833) errorbox 16332 sec after trigger time at 2026-02-26 15:10:31 UT, with upper limit up to 17.0 mag. The observations began at zenith distance = 81 deg. The sun altitude is -40.1 deg. The galactic latitude b = -45 deg., longitude l = 167 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3157390 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 16337 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 41.03s , +08d 13m 10.9s) | C | 10 | 16.4 | 16347 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 41.03s , +08d 13m 11.0s) | C | 30 | 17.0 | Coadd 16338 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 22.49s , +08d 16m 39.4s) | C | 10 | 16.0 | 16362 | 2026-02-26 15:10:56 | MASTER-Tunka | (02h 46m 34.45s , +08d 12m 33.1s) | C | 10 | 16.5 | 16363 | 2026-02-26 15:10:56 | MASTER-Tunka | (02h 46m 16.08s , +08d 15m 59.0s) | C | 10 | 15.8 | 16384 | 2026-02-26 15:11:18 | MASTER-Tunka | (02h 46m 33.55s , +08d 13m 32.1s) | C | 10 | 16.4 | 16384 | 2026-02-26 15:11:18 | MASTER-Tunka | (02h 46m 15.50s , +08d 16m 58.7s) | C | 10 | 16.0 | 16408 | 2026-02-26 15:11:41 | MASTER-Tunka | (02h 46m 40.83s , +08d 12m 31.4s) | C | 10 | 16.4 | 16408 | 2026-02-26 15:11:41 | MASTER-Tunka | (02h 46m 22.76s , +08d 15m 57.8s) | C | 10 | 15.9 | 16430 | 2026-02-26 15:12:04 | MASTER-Tunka | (02h 46m 33.93s , +08d 11m 31.6s) | C | 10 | 16.3 | 16431 | 2026-02-26 15:12:04 | MASTER-Tunka | (02h 46m 15.91s , +08d 14m 57.9s) | C | 10 | 15.8 | 16454 | 2026-02-26 15:12:27 | MASTER-Tunka | (02h 46m 40.26s , +08d 11m 42.7s) | C | 10 | 16.1 | 16454 | 2026-02-26 15:12:27 | MASTER-Tunka | (02h 46m 22.16s , +08d 15m 07.0s) | C | 10 | 15.3 | 16478 | 2026-02-26 15:12:52 | MASTER-Tunka | (02h 46m 37.35s , +08d 12m 56.4s) | C | 10 | 15.0 | 16479 | 2026-02-26 15:12:52 | MASTER-Tunka | (02h 46m 19.39s , +08d 16m 23.6s) | C | 10 | 14.8 | 16503 | 2026-02-26 15:13:17 | MASTER-Tunka | (02h 46m 37.23s , +08d 11m 26.2s) | C | 10 | 14.7 | 16503 | 2026-02-26 15:13:17 | MASTER-Tunka | (02h 46m 19.51s , +08d 14m 56.8s) | C | 10 | 14.6 | 16526 | 2026-02-26 15:13:40 | MASTER-Tunka | (02h 46m 39.73s , +08d 13m 11.3s) | C | 10 | 15.8 | 16527 | 2026-02-26 15:13:40 | MASTER-Tunka | (02h 46m 21.80s , +08d 16m 35.6s) | C | 10 | 15.2 | 16550 | 2026-02-26 15:14:03 | MASTER-Tunka | (02h 46m 33.44s , +08d 12m 29.2s) | C | 10 | 15.3 | 16550 | 2026-02-26 15:14:03 | MASTER-Tunka | (02h 46m 15.66s , +08d 15m 55.3s) | C | 10 | 14.9 | 16576 | 2026-02-26 15:14:30 | MASTER-Tunka | (02h 46m 34.78s , +08d 13m 28.4s) | C | 10 | 15.3 | 16577 | 2026-02-26 15:14:30 | MASTER-Tunka | (02h 46m 17.03s , +08d 16m 54.9s) | C | 10 | 15.1 | 16607 | 2026-02-26 15:15:01 | MASTER-Tunka | (02h 46m 40.60s , +08d 12m 25.3s) | C | 10 | 15.4 | 16607 | 2026-02-26 15:15:01 | MASTER-Tunka | (02h 46m 22.93s , +08d 15m 51.3s) | C | 10 | 14.9 | 16630 | 2026-02-26 15:15:23 | MASTER-Tunka | (02h 46m 33.66s , +08d 11m 26.0s) | C | 10 | 15.4 | 16630 | 2026-02-26 15:15:23 | MASTER-Tunka | (02h 46m 16.01s , +08d 14m 52.2s) | C | 10 | 15.1 | 16653 | 2026-02-26 15:15:46 | MASTER-Tunka | (02h 46m 41.11s , +08d 11m 47.9s) | C | 10 | 16.1 | 16653 | 2026-02-26 15:15:46 | MASTER-Tunka | (02h 46m 24.19s , +08d 15m 25.7s) | C | 10 | 14.8 | 16676 | 2026-02-26 15:16:09 | MASTER-Tunka | (02h 46m 37.35s , +08d 13m 13.3s) | C | 10 | 15.6 | 16676 | 2026-02-26 15:16:09 | MASTER-Tunka | (02h 46m 19.66s , +08d 16m 38.3s) | C | 10 | 15.2 | 16832 | 2026-02-26 15:18:43 | MASTER-Tunka | (02h 46m 34.69s , +08d 13m 32.9s) | C | 15 | 16.1 | 16832 | 2026-02-26 15:18:43 | MASTER-Tunka | (02h 46m 16.54s , +08d 16m 52.9s) | C | 15 | 15.5 | 16859 | 2026-02-26 15:19:09 | MASTER-Tunka | (02h 46m 40.75s , +08d 12m 32.7s) | C | 15 | 16.0 | 16859 | 2026-02-26 15:19:09 | MASTER-Tunka | (02h 46m 22.88s , +08d 15m 54.8s) | C | 15 | 15.4 | 16884 | 2026-02-26 15:19:37 | MASTER-Tunka | (02h 46m 35.06s , +08d 11m 32.5s) | C | 10 | 15.8 | 16884 | 2026-02-26 15:19:38 | MASTER-Tunka | (02h 46m 17.19s , +08d 14m 52.2s) | C | 10 | 15.2 | 16908 | 2026-02-26 15:20:02 | MASTER-Tunka | (02h 46m 41.38s , +08d 11m 36.4s) | C | 10 | 16.1 | 16908 | 2026-02-26 15:20:02 | MASTER-Tunka | (02h 46m 23.62s , +08d 14m 57.3s) | C | 10 | 15.4 | 16947 | 2026-02-26 15:20:41 | MASTER-Tunka | (02h 46m 38.12s , +08d 13m 07.4s) | C | 10 | 16.1 | 16947 | 2026-02-26 15:20:41 | MASTER-Tunka | (02h 46m 20.25s , +08d 16m 28.2s) | C | 10 | 15.4 | 16969 | 2026-02-26 15:21:02 | MASTER-Tunka | (02h 46m 38.11s , +08d 11m 37.5s) | C | 10 | 16.0 | 16969 | 2026-02-26 15:21:03 | MASTER-Tunka | (02h 46m 19.74s , +08d 14m 48.1s) | C | 10 | 15.5 | 16993 | 2026-02-26 15:21:26 | MASTER-Tunka | (02h 46m 40.15s , +08d 13m 08.3s) | C | 10 | 15.8 | 16993 | 2026-02-26 15:21:26 | MASTER-Tunka | (02h 46m 22.32s , +08d 16m 29.7s) | C | 10 | 15.3 | 17017 | 2026-02-26 15:21:51 | MASTER-Tunka | (02h 46m 35.71s , +08d 12m 33.0s) | C | 10 | 16.1 | 17017 | 2026-02-26 15:21:51 | MASTER-Tunka | (02h 46m 17.88s , +08d 15m 54.5s) | C | 10 | 15.4 | 17042 | 2026-02-26 15:22:16 | MASTER-Tunka | (02h 46m 35.36s , +08d 13m 30.6s) | C | 10 | 15.9 | 17042 | 2026-02-26 15:22:16 | MASTER-Tunka | (02h 46m 17.46s , +08d 16m 51.1s) | C | 10 | 15.2 | 17068 | 2026-02-26 15:22:41 | MASTER-Tunka | (02h 46m 40.47s , +08d 12m 31.9s) | C | 10 | 15.9 | 17068 | 2026-02-26 15:22:41 | MASTER-Tunka | (02h 46m 22.01s , +08d 15m 41.5s) | C | 10 | 15.5 | 17092 | 2026-02-26 15:23:05 | MASTER-Tunka | (02h 46m 35.02s , +08d 11m 33.0s) | C | 10 | 15.7 | 17092 | 2026-02-26 15:23:05 | MASTER-Tunka | (02h 46m 17.26s , +08d 14m 55.9s) | C | 10 | 15.2 | 17114 | 2026-02-26 15:23:27 | MASTER-Tunka | (02h 46m 41.21s , +08d 11m 47.1s) | C | 10 | 15.8 | 17114 | 2026-02-26 15:23:27 | MASTER-Tunka | (02h 46m 23.36s , +08d 15m 07.6s) | C | 10 | 15.5 | 17139 | 2026-02-26 15:23:52 | MASTER-Tunka | (02h 46m 38.16s , +08d 13m 22.7s) | C | 10 | 15.8 | 17139 | 2026-02-26 15:23:52 | MASTER-Tunka | (02h 46m 19.90s , +08d 16m 35.1s) | C | 10 | 15.3 | 17163 | 2026-02-26 15:24:16 | MASTER-Tunka | (02h 46m 38.13s , +08d 11m 34.8s) | C | 10 | 15.8 | 17163 | 2026-02-26 15:24:16 | MASTER-Tunka | (02h 46m 20.56s , +08d 15m 02.0s) | C | 10 | 15.3 | 17187 | 2026-02-26 15:24:40 | MASTER-Tunka | (02h 46m 41.99s , +08d 13m 24.9s) | C | 10 | 16.0 | 17187 | 2026-02-26 15:24:40 | MASTER-Tunka | (02h 46m 24.35s , +08d 16m 51.1s) | C | 10 | 15.3 | 17209 | 2026-02-26 15:25:03 | MASTER-Tunka | (02h 46m 35.05s , +08d 12m 30.7s) | C | 10 | 15.9 | 17209 | 2026-02-26 15:25:03 | MASTER-Tunka | (02h 46m 17.41s , +08d 15m 58.0s) | C | 10 | 15.2 | 17231 | 2026-02-26 15:25:25 | MASTER-Tunka | (02h 46m 34.52s , +08d 13m 31.1s) | C | 10 | 15.8 | 17231 | 2026-02-26 15:25:25 | MASTER-Tunka | (02h 46m 16.43s , +08d 16m 48.8s) | C | 10 | 15.2 | 17258 | 2026-02-26 15:25:51 | MASTER-Tunka | (02h 46m 41.61s , +08d 12m 31.5s) | C | 10 | 15.8 | 17258 | 2026-02-26 15:25:51 | MASTER-Tunka | (02h 46m 24.00s , +08d 15m 56.3s) | C | 10 | 15.3 | 17281 | 2026-02-26 15:26:14 | MASTER-Tunka | (02h 46m 34.33s , +08d 11m 30.5s) | C | 10 | 15.8 | 17281 | 2026-02-26 15:26:14 | MASTER-Tunka | (02h 46m 16.53s , +08d 14m 52.9s) | C | 10 | 15.2 | 17305 | 2026-02-26 15:26:38 | MASTER-Tunka | (02h 46m 40.80s , +08d 11m 40.7s) | C | 10 | 16.0 | 17305 | 2026-02-26 15:26:38 | MASTER-Tunka | (02h 46m 22.93s , +08d 14m 59.1s) | C | 10 | 15.2 | 17330 | 2026-02-26 15:27:03 | MASTER-Tunka | (02h 46m 37.97s , +08d 13m 22.4s) | C | 10 | 15.7 | 17330 | 2026-02-26 15:27:03 | MASTER-Tunka | (02h 46m 20.40s , +08d 16m 48.5s) | C | 10 | 15.2 | 17355 | 2026-02-26 15:27:29 | MASTER-Tunka | (02h 46m 38.21s , +08d 11m 42.8s) | C | 10 | 15.8 | 17356 | 2026-02-26 15:27:29 | MASTER-Tunka | (02h 46m 20.53s , +08d 15m 06.2s) | C | 10 | 15.2 | 17379 | 2026-02-26 15:27:52 | MASTER-Tunka | (02h 46m 40.47s , +08d 13m 29.7s) | C | 10 | 15.8 | 17379 | 2026-02-26 15:27:52 | MASTER-Tunka | (02h 46m 22.85s , +08d 16m 53.5s) | C | 10 | 15.2 | 17404 | 2026-02-26 15:28:18 | MASTER-Tunka | (02h 46m 34.36s , +08d 12m 28.4s) | C | 10 | 15.8 | 17404 | 2026-02-26 15:28:18 | MASTER-Tunka | (02h 46m 16.62s , +08d 15m 50.9s) | C | 10 | 15.2 | 17428 | 2026-02-26 15:28:41 | MASTER-Tunka | (02h 46m 35.07s , +08d 13m 27.8s) | C | 10 | 15.7 | 17428 | 2026-02-26 15:28:42 | MASTER-Tunka | (02h 46m 17.38s , +08d 16m 50.8s) | C | 10 | 15.1 | 17457 | 2026-02-26 15:29:10 | MASTER-Tunka | (02h 46m 39.98s , +08d 12m 26.4s) | C | 10 | 15.7 | 17457 | 2026-02-26 15:29:10 | MASTER-Tunka | (02h 46m 22.36s , +08d 15m 50.5s) | C | 10 | 15.1 | 17480 | 2026-02-26 15:29:33 | MASTER-Tunka | (02h 46m 34.99s , +08d 11m 25.9s) | C | 10 | 15.7 | 17480 | 2026-02-26 15:29:33 | MASTER-Tunka | (02h 46m 17.41s , +08d 14m 49.8s) | C | 10 | 15.2 | 17507 | 2026-02-26 15:30:01 | MASTER-Tunka | (02h 46m 40.94s , +08d 11m 33.4s) | C | 10 | 15.7 | 17507 | 2026-02-26 15:30:01 | MASTER-Tunka | (02h 46m 23.14s , +08d 14m 53.9s) | C | 10 | 15.1 | 17531 | 2026-02-26 15:30:24 | MASTER-Tunka | (02h 46m 37.85s , +08d 13m 16.0s) | C | 10 | 15.7 | 17531 | 2026-02-26 15:30:24 | MASTER-Tunka | (02h 46m 20.32s , +08d 16m 41.5s) | C | 10 | 15.0 | 17553 | 2026-02-26 15:30:46 | MASTER-Tunka | (02h 46m 37.93s , +08d 11m 54.6s) | C | 10 | 15.7 | 17553 | 2026-02-26 15:30:46 | MASTER-Tunka | (02h 46m 20.09s , +08d 15m 13.6s) | C | 10 | 15.0 | 17576 | 2026-02-26 15:31:10 | MASTER-Tunka | (02h 46m 40.42s , +08d 12m 54.8s) | C | 10 | 15.6 | 17576 | 2026-02-26 15:31:10 | MASTER-Tunka | (02h 46m 22.84s , +08d 16m 17.8s) | C | 10 | 14.9 | 17600 | 2026-02-26 15:31:33 | MASTER-Tunka | (02h 46m 34.70s , +08d 12m 22.5s) | C | 10 | 15.6 | 17600 | 2026-02-26 15:31:33 | MASTER-Tunka | (02h 46m 16.99s , +08d 15m 44.7s) | C | 10 | 15.1 | 17626 | 2026-02-26 15:32:00 | MASTER-Tunka | (02h 46m 35.77s , +08d 13m 23.5s) | C | 10 | 15.6 | 17626 | 2026-02-26 15:32:00 | MASTER-Tunka | (02h 46m 18.12s , +08d 16m 47.2s) | C | 10 | 15.1 | 17650 | 2026-02-26 15:32:23 | MASTER-Tunka | (02h 46m 40.81s , +08d 12m 21.6s) | C | 10 | 15.7 | 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/43848. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41963] LAT GRB260226.44: Global MASTER-Net observations report
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43848 SUBJECT: LAT GRB260226.44: Global MASTER-Net observations report DATE: 26/02/26 15:44:21 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-Tunka robotic telescope [1] located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the LAT GRB260226.44 (trigger No 793795080,02h 47m 41.04s , +07d 43m 12.0s, R=0.105833) errorbox 16332 sec after trigger time at 2026-02-26 15:10:31 UT, with upper limit up to 17.0 mag. The observations began at zenith distance = 81 deg. The sun altitude is -40.1 deg. The galactic latitude b = -45 deg., longitude l = 167 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3157390 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 16337 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 41.03s , +08d 13m 10.9s) | C | 10 | 16.4 | 16347 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 41.03s , +08d 13m 11.0s) | C | 30 | 17.0 | Coadd 16338 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 22.49s , +08d 16m 39.4s) | C | 10 | 16.0 | 16362 | 2026-02-26 15:10:56 | MASTER-Tunka | (02h 46m 34.45s , +08d 12m 33.1s) | C | 10 | 16.5 | 16363 | 2026-02-26 15:10:56 | MASTER-Tunka | (02h 46m 16.08s , +08d 15m 59.0s) | C | 10 | 15.8 | 16384 | 2026-02-26 15:11:18 | MASTER-Tunka | (02h 46m 33.55s , +08d 13m 32.1s) | C | 10 | 16.4 | 16384 | 2026-02-26 15:11:18 | MASTER-Tunka | (02h 46m 15.50s , +08d 16m 58.7s) | C | 10 | 16.0 | 16408 | 2026-02-26 15:11:41 | MASTER-Tunka | (02h 46m 40.83s , +08d 12m 31.4s) | C | 10 | 16.4 | 16408 | 2026-02-26 15:11:41 | MASTER-Tunka | (02h 46m 22.76s , +08d 15m 57.8s) | C | 10 | 15.9 | 16430 | 2026-02-26 15:12:04 | MASTER-Tunka | (02h 46m 33.93s , +08d 11m 31.6s) | C | 10 | 16.3 | 16431 | 2026-02-26 15:12:04 | MASTER-Tunka | (02h 46m 15.91s , +08d 14m 57.9s) | C | 10 | 15.8 | 16454 | 2026-02-26 15:12:27 | MASTER-Tunka | (02h 46m 40.26s , +08d 11m 42.7s) | C | 10 | 16.1 | 16454 | 2026-02-26 15:12:27 | MASTER-Tunka | (02h 46m 22.16s , +08d 15m 07.0s) | C | 10 | 15.3 | 16478 | 2026-02-26 15:12:52 | MASTER-Tunka | (02h 46m 37.35s , +08d 12m 56.4s) | C | 10 | 15.0 | 16479 | 2026-02-26 15:12:52 | MASTER-Tunka | (02h 46m 19.39s , +08d 16m 23.6s) | C | 10 | 14.8 | 16503 | 2026-02-26 15:13:17 | MASTER-Tunka | (02h 46m 37.23s , +08d 11m 26.2s) | C | 10 | 14.7 | 16503 | 2026-02-26 15:13:17 | MASTER-Tunka | (02h 46m 19.51s , +08d 14m 56.8s) | C | 10 | 14.6 | 16526 | 2026-02-26 15:13:40 | MASTER-Tunka | (02h 46m 39.73s , +08d 13m 11.3s) | C | 10 | 15.8 | 16527 | 2026-02-26 15:13:40 | MASTER-Tunka | (02h 46m 21.80s , +08d 16m 35.6s) | C | 10 | 15.2 | 16550 | 2026-02-26 15:14:03 | MASTER-Tunka | (02h 46m 33.44s , +08d 12m 29.2s) | C | 10 | 15.3 | 16550 | 2026-02-26 15:14:03 | MASTER-Tunka | (02h 46m 15.66s , +08d 15m 55.3s) | C | 10 | 14.9 | 16576 | 2026-02-26 15:14:30 | MASTER-Tunka | (02h 46m 34.78s , +08d 13m 28.4s) | C | 10 | 15.3 | 16577 | 2026-02-26 15:14:30 | MASTER-Tunka | (02h 46m 17.03s , +08d 16m 54.9s) | C | 10 | 15.1 | 16607 | 2026-02-26 15:15:01 | MASTER-Tunka | (02h 46m 40.60s , +08d 12m 25.3s) | C | 10 | 15.4 | 16607 | 2026-02-26 15:15:01 | MASTER-Tunka | (02h 46m 22.93s , +08d 15m 51.3s) | C | 10 | 14.9 | 16630 | 2026-02-26 15:15:23 | MASTER-Tunka | (02h 46m 33.66s , +08d 11m 26.0s) | C | 10 | 15.4 | 16630 | 2026-02-26 15:15:23 | MASTER-Tunka | (02h 46m 16.01s , +08d 14m 52.2s) | C | 10 | 15.1 | 16653 | 2026-02-26 15:15:46 | MASTER-Tunka | (02h 46m 41.11s , +08d 11m 47.9s) | C | 10 | 16.1 | 16653 | 2026-02-26 15:15:46 | MASTER-Tunka | (02h 46m 24.19s , +08d 15m 25.7s) | C | 10 | 14.8 | 16676 | 2026-02-26 15:16:09 | MASTER-Tunka | (02h 46m 37.35s , +08d 13m 13.3s) | C | 10 | 15.6 | 16676 | 2026-02-26 15:16:09 | MASTER-Tunka | (02h 46m 19.66s , +08d 16m 38.3s) | C | 10 | 15.2 | 16832 | 2026-02-26 15:18:43 | MASTER-Tunka | (02h 46m 34.69s , +08d 13m 32.9s) | C | 15 | 16.1 | 16832 | 2026-02-26 15:18:43 | MASTER-Tunka | (02h 46m 16.54s , +08d 16m 52.9s) | C | 15 | 15.5 | 16859 | 2026-02-26 15:19:09 | MASTER-Tunka | (02h 46m 40.75s , +08d 12m 32.7s) | C | 15 | 16.0 | 16859 | 2026-02-26 15:19:09 | MASTER-Tunka | (02h 46m 22.88s , +08d 15m 54.8s) | C | 15 | 15.4 | 16884 | 2026-02-26 15:19:37 | MASTER-Tunka | (02h 46m 35.06s , +08d 11m 32.5s) | C | 10 | 15.8 | 16884 | 2026-02-26 15:19:38 | MASTER-Tunka | (02h 46m 17.19s , +08d 14m 52.2s) | C | 10 | 15.2 | 16908 | 2026-02-26 15:20:02 | MASTER-Tunka | (02h 46m 41.38s , +08d 11m 36.4s) | C | 10 | 16.1 | 16908 | 2026-02-26 15:20:02 | MASTER-Tunka | (02h 46m 23.62s , +08d 14m 57.3s) | C | 10 | 15.4 | 16947 | 2026-02-26 15:20:41 | MASTER-Tunka | (02h 46m 38.12s , +08d 13m 07.4s) | C | 10 | 16.1 | 16947 | 2026-02-26 15:20:41 | MASTER-Tunka | (02h 46m 20.25s , +08d 16m 28.2s) | C | 10 | 15.4 | 16969 | 2026-02-26 15:21:02 | MASTER-Tunka | (02h 46m 38.11s , +08d 11m 37.5s) | C | 10 | 16.0 | 16969 | 2026-02-26 15:21:03 | MASTER-Tunka | (02h 46m 19.74s , +08d 14m 48.1s) | C | 10 | 15.5 | 16993 | 2026-02-26 15:21:26 | MASTER-Tunka | (02h 46m 40.15s , +08d 13m 08.3s) | C | 10 | 15.8 | 16993 | 2026-02-26 15:21:26 | MASTER-Tunka | (02h 46m 22.32s , +08d 16m 29.7s) | C | 10 | 15.3 | 17017 | 2026-02-26 15:21:51 | MASTER-Tunka | (02h 46m 35.71s , +08d 12m 33.0s) | C | 10 | 16.1 | 17017 | 2026-02-26 15:21:51 | MASTER-Tunka | (02h 46m 17.88s , +08d 15m 54.5s) | C | 10 | 15.4 | 17042 | 2026-02-26 15:22:16 | MASTER-Tunka | (02h 46m 35.36s , +08d 13m 30.6s) | C | 10 | 15.9 | 17042 | 2026-02-26 15:22:16 | MASTER-Tunka | (02h 46m 17.46s , +08d 16m 51.1s) | C | 10 | 15.2 | 17068 | 2026-02-26 15:22:41 | MASTER-Tunka | (02h 46m 40.47s , +08d 12m 31.9s) | C | 10 | 15.9 | 17068 | 2026-02-26 15:22:41 | MASTER-Tunka | (02h 46m 22.01s , +08d 15m 41.5s) | C | 10 | 15.5 | 17092 | 2026-02-26 15:23:05 | MASTER-Tunka | (02h 46m 35.02s , +08d 11m 33.0s) | C | 10 | 15.7 | 17092 | 2026-02-26 15:23:05 | MASTER-Tunka | (02h 46m 17.26s , +08d 14m 55.9s) | C | 10 | 15.2 | 17114 | 2026-02-26 15:23:27 | MASTER-Tunka | (02h 46m 41.21s , +08d 11m 47.1s) | C | 10 | 15.8 | 17114 | 2026-02-26 15:23:27 | MASTER-Tunka | (02h 46m 23.36s , +08d 15m 07.6s) | C | 10 | 15.5 | 17139 | 2026-02-26 15:23:52 | MASTER-Tunka | (02h 46m 38.16s , +08d 13m 22.7s) | C | 10 | 15.8 | 17139 | 2026-02-26 15:23:52 | MASTER-Tunka | (02h 46m 19.90s , +08d 16m 35.1s) | C | 10 | 15.3 | 17163 | 2026-02-26 15:24:16 | MASTER-Tunka | (02h 46m 38.13s , +08d 11m 34.8s) | C | 10 | 15.8 | 17163 | 2026-02-26 15:24:16 | MASTER-Tunka | (02h 46m 20.56s , +08d 15m 02.0s) | C | 10 | 15.3 | 17187 | 2026-02-26 15:24:40 | MASTER-Tunka | (02h 46m 41.99s , +08d 13m 24.9s) | C | 10 | 16.0 | 17187 | 2026-02-26 15:24:40 | MASTER-Tunka | (02h 46m 24.35s , +08d 16m 51.1s) | C | 10 | 15.3 | 17209 | 2026-02-26 15:25:03 | MASTER-Tunka | (02h 46m 35.05s , +08d 12m 30.7s) | C | 10 | 15.9 | 17209 | 2026-02-26 15:25:03 | MASTER-Tunka | (02h 46m 17.41s , +08d 15m 58.0s) | C | 10 | 15.2 | 17231 | 2026-02-26 15:25:25 | MASTER-Tunka | (02h 46m 34.52s , +08d 13m 31.1s) | C | 10 | 15.8 | 17231 | 2026-02-26 15:25:25 | MASTER-Tunka | (02h 46m 16.43s , +08d 16m 48.8s) | C | 10 | 15.2 | 17258 | 2026-02-26 15:25:51 | MASTER-Tunka | (02h 46m 41.61s , +08d 12m 31.5s) | C | 10 | 15.8 | 17258 | 2026-02-26 15:25:51 | MASTER-Tunka | (02h 46m 24.00s , +08d 15m 56.3s) | C | 10 | 15.3 | 17281 | 2026-02-26 15:26:14 | MASTER-Tunka | (02h 46m 34.33s , +08d 11m 30.5s) | C | 10 | 15.8 | 17281 | 2026-02-26 15:26:14 | MASTER-Tunka | (02h 46m 16.53s , +08d 14m 52.9s) | C | 10 | 15.2 | 17305 | 2026-02-26 15:26:38 | MASTER-Tunka | (02h 46m 40.80s , +08d 11m 40.7s) | C | 10 | 16.0 | 17305 | 2026-02-26 15:26:38 | MASTER-Tunka | (02h 46m 22.93s , +08d 14m 59.1s) | C | 10 | 15.2 | 17330 | 2026-02-26 15:27:03 | MASTER-Tunka | (02h 46m 37.97s , +08d 13m 22.4s) | C | 10 | 15.7 | 17330 | 2026-02-26 15:27:03 | MASTER-Tunka | (02h 46m 20.40s , +08d 16m 48.5s) | C | 10 | 15.2 | 17355 | 2026-02-26 15:27:29 | MASTER-Tunka | (02h 46m 38.21s , +08d 11m 42.8s) | C | 10 | 15.8 | 17356 | 2026-02-26 15:27:29 | MASTER-Tunka | (02h 46m 20.53s , +08d 15m 06.2s) | C | 10 | 15.2 | 17379 | 2026-02-26 15:27:52 | MASTER-Tunka | (02h 46m 40.47s , +08d 13m 29.7s) | C | 10 | 15.8 | 17379 | 2026-02-26 15:27:52 | MASTER-Tunka | (02h 46m 22.85s , +08d 16m 53.5s) | C | 10 | 15.2 | 17404 | 2026-02-26 15:28:18 | MASTER-Tunka | (02h 46m 34.36s , +08d 12m 28.4s) | C | 10 | 15.8 | 17404 | 2026-02-26 15:28:18 | MASTER-Tunka | (02h 46m 16.62s , +08d 15m 50.9s) | C | 10 | 15.2 | 17428 | 2026-02-26 15:28:41 | MASTER-Tunka | (02h 46m 35.07s , +08d 13m 27.8s) | C | 10 | 15.7 | 17428 | 2026-02-26 15:28:42 | MASTER-Tunka | (02h 46m 17.38s , +08d 16m 50.8s) | C | 10 | 15.1 | 17457 | 2026-02-26 15:29:10 | MASTER-Tunka | (02h 46m 39.98s , +08d 12m 26.4s) | C | 10 | 15.7 | 17457 | 2026-02-26 15:29:10 | MASTER-Tunka | (02h 46m 22.36s , +08d 15m 50.5s) | C | 10 | 15.1 | 17480 | 2026-02-26 15:29:33 | MASTER-Tunka | (02h 46m 34.99s , +08d 11m 25.9s) | C | 10 | 15.7 | 17480 | 2026-02-26 15:29:33 | MASTER-Tunka | (02h 46m 17.41s , +08d 14m 49.8s) | C | 10 | 15.2 | 17507 | 2026-02-26 15:30:01 | MASTER-Tunka | (02h 46m 40.94s , +08d 11m 33.4s) | C | 10 | 15.7 | 17507 | 2026-02-26 15:30:01 | MASTER-Tunka | (02h 46m 23.14s , +08d 14m 53.9s) | C | 10 | 15.1 | 17531 | 2026-02-26 15:30:24 | MASTER-Tunka | (02h 46m 37.85s , +08d 13m 16.0s) | C | 10 | 15.7 | 17531 | 2026-02-26 15:30:24 | MASTER-Tunka | (02h 46m 20.32s , +08d 16m 41.5s) | C | 10 | 15.0 | 17553 | 2026-02-26 15:30:46 | MASTER-Tunka | (02h 46m 37.93s , +08d 11m 54.6s) | C | 10 | 15.7 | 17553 | 2026-02-26 15:30:46 | MASTER-Tunka | (02h 46m 20.09s , +08d 15m 13.6s) | C | 10 | 15.0 | 17576 | 2026-02-26 15:31:10 | MASTER-Tunka | (02h 46m 40.42s , +08d 12m 54.8s) | C | 10 | 15.6 | 17576 | 2026-02-26 15:31:10 | MASTER-Tunka | (02h 46m 22.84s , +08d 16m 17.8s) | C | 10 | 14.9 | 17600 | 2026-02-26 15:31:33 | MASTER-Tunka | (02h 46m 34.70s , +08d 12m 22.5s) | C | 10 | 15.6 | 17600 | 2026-02-26 15:31:33 | MASTER-Tunka | (02h 46m 16.99s , +08d 15m 44.7s) | C | 10 | 15.1 | 17626 | 2026-02-26 15:32:00 | MASTER-Tunka | (02h 46m 35.77s , +08d 13m 23.5s) | C | 10 | 15.6 | 17626 | 2026-02-26 15:32:00 | MASTER-Tunka | (02h 46m 18.12s , +08d 16m 47.2s) | C | 10 | 15.1 | 17650 | 2026-02-26 15:32:23 | MASTER-Tunka | (02h 46m 40.81s , +08d 12m 21.6s) | C | 10 | 15.7 | 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/43848. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41962] LAT GRB260226.44: Global MASTER-Net observations report
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43848 SUBJECT: LAT GRB260226.44: Global MASTER-Net observations report DATE: 26/02/26 15:44:21 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-Tunka robotic telescope [1] located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the LAT GRB260226.44 (trigger No 793795080,02h 47m 41.04s , +07d 43m 12.0s, R=0.105833) errorbox 16332 sec after trigger time at 2026-02-26 15:10:31 UT, with upper limit up to 17.0 mag. The observations began at zenith distance = 81 deg. The sun altitude is -40.1 deg. The galactic latitude b = -45 deg., longitude l = 167 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3157390 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 16337 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 41.03s , +08d 13m 10.9s) | C | 10 | 16.4 | 16347 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 41.03s , +08d 13m 11.0s) | C | 30 | 17.0 | Coadd 16338 | 2026-02-26 15:10:31 | MASTER-Tunka | (02h 46m 22.49s , +08d 16m 39.4s) | C | 10 | 16.0 | 16362 | 2026-02-26 15:10:56 | MASTER-Tunka | (02h 46m 34.45s , +08d 12m 33.1s) | C | 10 | 16.5 | 16363 | 2026-02-26 15:10:56 | MASTER-Tunka | (02h 46m 16.08s , +08d 15m 59.0s) | C | 10 | 15.8 | 16384 | 2026-02-26 15:11:18 | MASTER-Tunka | (02h 46m 33.55s , +08d 13m 32.1s) | C | 10 | 16.4 | 16384 | 2026-02-26 15:11:18 | MASTER-Tunka | (02h 46m 15.50s , +08d 16m 58.7s) | C | 10 | 16.0 | 16408 | 2026-02-26 15:11:41 | MASTER-Tunka | (02h 46m 40.83s , +08d 12m 31.4s) | C | 10 | 16.4 | 16408 | 2026-02-26 15:11:41 | MASTER-Tunka | (02h 46m 22.76s , +08d 15m 57.8s) | C | 10 | 15.9 | 16430 | 2026-02-26 15:12:04 | MASTER-Tunka | (02h 46m 33.93s , +08d 11m 31.6s) | C | 10 | 16.3 | 16431 | 2026-02-26 15:12:04 | MASTER-Tunka | (02h 46m 15.91s , +08d 14m 57.9s) | C | 10 | 15.8 | 16454 | 2026-02-26 15:12:27 | MASTER-Tunka | (02h 46m 40.26s , +08d 11m 42.7s) | C | 10 | 16.1 | 16454 | 2026-02-26 15:12:27 | MASTER-Tunka | (02h 46m 22.16s , +08d 15m 07.0s) | C | 10 | 15.3 | 16478 | 2026-02-26 15:12:52 | MASTER-Tunka | (02h 46m 37.35s , +08d 12m 56.4s) | C | 10 | 15.0 | 16479 | 2026-02-26 15:12:52 | MASTER-Tunka | (02h 46m 19.39s , +08d 16m 23.6s) | C | 10 | 14.8 | 16503 | 2026-02-26 15:13:17 | MASTER-Tunka | (02h 46m 37.23s , +08d 11m 26.2s) | C | 10 | 14.7 | 16503 | 2026-02-26 15:13:17 | MASTER-Tunka | (02h 46m 19.51s , +08d 14m 56.8s) | C | 10 | 14.6 | 16526 | 2026-02-26 15:13:40 | MASTER-Tunka | (02h 46m 39.73s , +08d 13m 11.3s) | C | 10 | 15.8 | 16527 | 2026-02-26 15:13:40 | MASTER-Tunka | (02h 46m 21.80s , +08d 16m 35.6s) | C | 10 | 15.2 | 16550 | 2026-02-26 15:14:03 | MASTER-Tunka | (02h 46m 33.44s , +08d 12m 29.2s) | C | 10 | 15.3 | 16550 | 2026-02-26 15:14:03 | MASTER-Tunka | (02h 46m 15.66s , +08d 15m 55.3s) | C | 10 | 14.9 | 16576 | 2026-02-26 15:14:30 | MASTER-Tunka | (02h 46m 34.78s , +08d 13m 28.4s) | C | 10 | 15.3 | 16577 | 2026-02-26 15:14:30 | MASTER-Tunka | (02h 46m 17.03s , +08d 16m 54.9s) | C | 10 | 15.1 | 16607 | 2026-02-26 15:15:01 | MASTER-Tunka | (02h 46m 40.60s , +08d 12m 25.3s) | C | 10 | 15.4 | 16607 | 2026-02-26 15:15:01 | MASTER-Tunka | (02h 46m 22.93s , +08d 15m 51.3s) | C | 10 | 14.9 | 16630 | 2026-02-26 15:15:23 | MASTER-Tunka | (02h 46m 33.66s , +08d 11m 26.0s) | C | 10 | 15.4 | 16630 | 2026-02-26 15:15:23 | MASTER-Tunka | (02h 46m 16.01s , +08d 14m 52.2s) | C | 10 | 15.1 | 16653 | 2026-02-26 15:15:46 | MASTER-Tunka | (02h 46m 41.11s , +08d 11m 47.9s) | C | 10 | 16.1 | 16653 | 2026-02-26 15:15:46 | MASTER-Tunka | (02h 46m 24.19s , +08d 15m 25.7s) | C | 10 | 14.8 | 16676 | 2026-02-26 15:16:09 | MASTER-Tunka | (02h 46m 37.35s , +08d 13m 13.3s) | C | 10 | 15.6 | 16676 | 2026-02-26 15:16:09 | MASTER-Tunka | (02h 46m 19.66s , +08d 16m 38.3s) | C | 10 | 15.2 | 16832 | 2026-02-26 15:18:43 | MASTER-Tunka | (02h 46m 34.69s , +08d 13m 32.9s) | C | 15 | 16.1 | 16832 | 2026-02-26 15:18:43 | MASTER-Tunka | (02h 46m 16.54s , +08d 16m 52.9s) | C | 15 | 15.5 | 16859 | 2026-02-26 15:19:09 | MASTER-Tunka | (02h 46m 40.75s , +08d 12m 32.7s) | C | 15 | 16.0 | 16859 | 2026-02-26 15:19:09 | MASTER-Tunka | (02h 46m 22.88s , +08d 15m 54.8s) | C | 15 | 15.4 | 16884 | 2026-02-26 15:19:37 | MASTER-Tunka | (02h 46m 35.06s , +08d 11m 32.5s) | C | 10 | 15.8 | 16884 | 2026-02-26 15:19:38 | MASTER-Tunka | (02h 46m 17.19s , +08d 14m 52.2s) | C | 10 | 15.2 | 16908 | 2026-02-26 15:20:02 | MASTER-Tunka | (02h 46m 41.38s , +08d 11m 36.4s) | C | 10 | 16.1 | 16908 | 2026-02-26 15:20:02 | MASTER-Tunka | (02h 46m 23.62s , +08d 14m 57.3s) | C | 10 | 15.4 | 16947 | 2026-02-26 15:20:41 | MASTER-Tunka | (02h 46m 38.12s , +08d 13m 07.4s) | C | 10 | 16.1 | 16947 | 2026-02-26 15:20:41 | MASTER-Tunka | (02h 46m 20.25s , +08d 16m 28.2s) | C | 10 | 15.4 | 16969 | 2026-02-26 15:21:02 | MASTER-Tunka | (02h 46m 38.11s , +08d 11m 37.5s) | C | 10 | 16.0 | 16969 | 2026-02-26 15:21:03 | MASTER-Tunka | (02h 46m 19.74s , +08d 14m 48.1s) | C | 10 | 15.5 | 16993 | 2026-02-26 15:21:26 | MASTER-Tunka | (02h 46m 40.15s , +08d 13m 08.3s) | C | 10 | 15.8 | 16993 | 2026-02-26 15:21:26 | MASTER-Tunka | (02h 46m 22.32s , +08d 16m 29.7s) | C | 10 | 15.3 | 17017 | 2026-02-26 15:21:51 | MASTER-Tunka | (02h 46m 35.71s , +08d 12m 33.0s) | C | 10 | 16.1 | 17017 | 2026-02-26 15:21:51 | MASTER-Tunka | (02h 46m 17.88s , +08d 15m 54.5s) | C | 10 | 15.4 | 17042 | 2026-02-26 15:22:16 | MASTER-Tunka | (02h 46m 35.36s , +08d 13m 30.6s) | C | 10 | 15.9 | 17042 | 2026-02-26 15:22:16 | MASTER-Tunka | (02h 46m 17.46s , +08d 16m 51.1s) | C | 10 | 15.2 | 17068 | 2026-02-26 15:22:41 | MASTER-Tunka | (02h 46m 40.47s , +08d 12m 31.9s) | C | 10 | 15.9 | 17068 | 2026-02-26 15:22:41 | MASTER-Tunka | (02h 46m 22.01s , +08d 15m 41.5s) | C | 10 | 15.5 | 17092 | 2026-02-26 15:23:05 | MASTER-Tunka | (02h 46m 35.02s , +08d 11m 33.0s) | C | 10 | 15.7 | 17092 | 2026-02-26 15:23:05 | MASTER-Tunka | (02h 46m 17.26s , +08d 14m 55.9s) | C | 10 | 15.2 | 17114 | 2026-02-26 15:23:27 | MASTER-Tunka | (02h 46m 41.21s , +08d 11m 47.1s) | C | 10 | 15.8 | 17114 | 2026-02-26 15:23:27 | MASTER-Tunka | (02h 46m 23.36s , +08d 15m 07.6s) | C | 10 | 15.5 | 17139 | 2026-02-26 15:23:52 | MASTER-Tunka | (02h 46m 38.16s , +08d 13m 22.7s) | C | 10 | 15.8 | 17139 | 2026-02-26 15:23:52 | MASTER-Tunka | (02h 46m 19.90s , +08d 16m 35.1s) | C | 10 | 15.3 | 17163 | 2026-02-26 15:24:16 | MASTER-Tunka | (02h 46m 38.13s , +08d 11m 34.8s) | C | 10 | 15.8 | 17163 | 2026-02-26 15:24:16 | MASTER-Tunka | (02h 46m 20.56s , +08d 15m 02.0s) | C | 10 | 15.3 | 17187 | 2026-02-26 15:24:40 | MASTER-Tunka | (02h 46m 41.99s , +08d 13m 24.9s) | C | 10 | 16.0 | 17187 | 2026-02-26 15:24:40 | MASTER-Tunka | (02h 46m 24.35s , +08d 16m 51.1s) | C | 10 | 15.3 | 17209 | 2026-02-26 15:25:03 | MASTER-Tunka | (02h 46m 35.05s , +08d 12m 30.7s) | C | 10 | 15.9 | 17209 | 2026-02-26 15:25:03 | MASTER-Tunka | (02h 46m 17.41s , +08d 15m 58.0s) | C | 10 | 15.2 | 17231 | 2026-02-26 15:25:25 | MASTER-Tunka | (02h 46m 34.52s , +08d 13m 31.1s) | C | 10 | 15.8 | 17231 | 2026-02-26 15:25:25 | MASTER-Tunka | (02h 46m 16.43s , +08d 16m 48.8s) | C | 10 | 15.2 | 17258 | 2026-02-26 15:25:51 | MASTER-Tunka | (02h 46m 41.61s , +08d 12m 31.5s) | C | 10 | 15.8 | 17258 | 2026-02-26 15:25:51 | MASTER-Tunka | (02h 46m 24.00s , +08d 15m 56.3s) | C | 10 | 15.3 | 17281 | 2026-02-26 15:26:14 | MASTER-Tunka | (02h 46m 34.33s , +08d 11m 30.5s) | C | 10 | 15.8 | 17281 | 2026-02-26 15:26:14 | MASTER-Tunka | (02h 46m 16.53s , +08d 14m 52.9s) | C | 10 | 15.2 | 17305 | 2026-02-26 15:26:38 | MASTER-Tunka | (02h 46m 40.80s , +08d 11m 40.7s) | C | 10 | 16.0 | 17305 | 2026-02-26 15:26:38 | MASTER-Tunka | (02h 46m 22.93s , +08d 14m 59.1s) | C | 10 | 15.2 | 17330 | 2026-02-26 15:27:03 | MASTER-Tunka | (02h 46m 37.97s , +08d 13m 22.4s) | C | 10 | 15.7 | 17330 | 2026-02-26 15:27:03 | MASTER-Tunka | (02h 46m 20.40s , +08d 16m 48.5s) | C | 10 | 15.2 | 17355 | 2026-02-26 15:27:29 | MASTER-Tunka | (02h 46m 38.21s , +08d 11m 42.8s) | C | 10 | 15.8 | 17356 | 2026-02-26 15:27:29 | MASTER-Tunka | (02h 46m 20.53s , +08d 15m 06.2s) | C | 10 | 15.2 | 17379 | 2026-02-26 15:27:52 | MASTER-Tunka | (02h 46m 40.47s , +08d 13m 29.7s) | C | 10 | 15.8 | 17379 | 2026-02-26 15:27:52 | MASTER-Tunka | (02h 46m 22.85s , +08d 16m 53.5s) | C | 10 | 15.2 | 17404 | 2026-02-26 15:28:18 | MASTER-Tunka | (02h 46m 34.36s , +08d 12m 28.4s) | C | 10 | 15.8 | 17404 | 2026-02-26 15:28:18 | MASTER-Tunka | (02h 46m 16.62s , +08d 15m 50.9s) | C | 10 | 15.2 | 17428 | 2026-02-26 15:28:41 | MASTER-Tunka | (02h 46m 35.07s , +08d 13m 27.8s) | C | 10 | 15.7 | 17428 | 2026-02-26 15:28:42 | MASTER-Tunka | (02h 46m 17.38s , +08d 16m 50.8s) | C | 10 | 15.1 | 17457 | 2026-02-26 15:29:10 | MASTER-Tunka | (02h 46m 39.98s , +08d 12m 26.4s) | C | 10 | 15.7 | 17457 | 2026-02-26 15:29:10 | MASTER-Tunka | (02h 46m 22.36s , +08d 15m 50.5s) | C | 10 | 15.1 | 17480 | 2026-02-26 15:29:33 | MASTER-Tunka | (02h 46m 34.99s , +08d 11m 25.9s) | C | 10 | 15.7 | 17480 | 2026-02-26 15:29:33 | MASTER-Tunka | (02h 46m 17.41s , +08d 14m 49.8s) | C | 10 | 15.2 | 17507 | 2026-02-26 15:30:01 | MASTER-Tunka | (02h 46m 40.94s , +08d 11m 33.4s) | C | 10 | 15.7 | 17507 | 2026-02-26 15:30:01 | MASTER-Tunka | (02h 46m 23.14s , +08d 14m 53.9s) | C | 10 | 15.1 | 17531 | 2026-02-26 15:30:24 | MASTER-Tunka | (02h 46m 37.85s , +08d 13m 16.0s) | C | 10 | 15.7 | 17531 | 2026-02-26 15:30:24 | MASTER-Tunka | (02h 46m 20.32s , +08d 16m 41.5s) | C | 10 | 15.0 | 17553 | 2026-02-26 15:30:46 | MASTER-Tunka | (02h 46m 37.93s , +08d 11m 54.6s) | C | 10 | 15.7 | 17553 | 2026-02-26 15:30:46 | MASTER-Tunka | (02h 46m 20.09s , +08d 15m 13.6s) | C | 10 | 15.0 | 17576 | 2026-02-26 15:31:10 | MASTER-Tunka | (02h 46m 40.42s , +08d 12m 54.8s) | C | 10 | 15.6 | 17576 | 2026-02-26 15:31:10 | MASTER-Tunka | (02h 46m 22.84s , +08d 16m 17.8s) | C | 10 | 14.9 | 17600 | 2026-02-26 15:31:33 | MASTER-Tunka | (02h 46m 34.70s , +08d 12m 22.5s) | C | 10 | 15.6 | 17600 | 2026-02-26 15:31:33 | MASTER-Tunka | (02h 46m 16.99s , +08d 15m 44.7s) | C | 10 | 15.1 | 17626 | 2026-02-26 15:32:00 | MASTER-Tunka | (02h 46m 35.77s , +08d 13m 23.5s) | C | 10 | 15.6 | 17626 | 2026-02-26 15:32:00 | MASTER-Tunka | (02h 46m 18.12s , +08d 16m 47.2s) | C | 10 | 15.1 | 17650 | 2026-02-26 15:32:23 | MASTER-Tunka | (02h 46m 40.81s , +08d 12m 21.6s) | C | 10 | 15.7 | 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/43848. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41961] Fermi GRB 260226A: Global MASTER-Net observations report
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43847 SUBJECT: Fermi GRB 260226A: Global MASTER-Net observations report DATE: 26/02/26 15:31:16 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-Tunka robotic telescope [1] located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 260226A ( Fermi GBM team, GCN 43840) errorbox 11103 sec after notice time and 11134 sec after trigger time at 2026-02-26 13:43:30 UT, with upper limit up to 19.1 mag. The observations began at zenith distance = 59 deg. The sun altitude is -28.9 deg. The galactic latitude b = -36 deg., longitude l = 164 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3156987 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 11139 | 2026-02-26 13:43:30 | MASTER-Tunka | (02h 58m 57.34s , +16d 00m 41.9s) | C | 10 | 18.0 | 11139 | 2026-02-26 13:43:30 | MASTER-Tunka | (02h 59m 23.46s , +15d 56m 15.9s) | C | 10 | 17.9 | 11149 | 2026-02-26 13:43:30 | MASTER-Tunka | (02h 59m 23.46s , +15d 56m 15.9s) | C | 30 | 18.8 | Coadd 11163 | 2026-02-26 13:43:54 | MASTER-Tunka | (02h 58m 52.12s , +15d 59m 40.3s) | C | 10 | 18.0 | 11163 | 2026-02-26 13:43:54 | MASTER-Tunka | (02h 59m 18.19s , +15d 55m 14.9s) | C | 10 | 17.9 | 11187 | 2026-02-26 13:44:17 | MASTER-Tunka | (02h 59m 23.99s , +15d 55m 25.8s) | C | 10 | 17.9 | 11187 | 2026-02-26 13:44:17 | MASTER-Tunka | (02h 58m 57.93s , +15d 59m 51.0s) | C | 10 | 18.1 | 11212 | 2026-02-26 13:44:42 | MASTER-Tunka | (02h 58m 54.73s , +16d 01m 23.4s) | C | 10 | 18.0 | 11212 | 2026-02-26 13:44:42 | MASTER-Tunka | (02h 59m 20.78s , +15d 56m 58.6s) | C | 10 | 17.9 | 11222 | 2026-02-26 13:44:42 | MASTER-Tunka | (02h 59m 20.78s , +15d 56m 58.6s) | C | 30 | 18.7 | Coadd 11236 | 2026-02-26 13:45:07 | MASTER-Tunka | (02h 58m 54.78s , +15d 59m 58.2s) | C | 10 | 17.9 | 11236 | 2026-02-26 13:45:07 | MASTER-Tunka | (02h 59m 20.82s , +15d 55m 33.4s) | C | 10 | 18.0 | 11261 | 2026-02-26 13:45:31 | MASTER-Tunka | (02h 58m 57.44s , +16d 01m 12.6s) | C | 10 | 18.0 | 11261 | 2026-02-26 13:45:31 | MASTER-Tunka | (02h 59m 23.48s , +15d 56m 47.9s) | C | 10 | 17.9 | 11284 | 2026-02-26 13:45:55 | MASTER-Tunka | (02h 58m 52.43s , +16d 00m 36.6s) | C | 10 | 17.9 | 11284 | 2026-02-26 13:45:55 | MASTER-Tunka | (02h 59m 18.47s , +15d 56m 12.1s) | C | 10 | 18.0 | 11294 | 2026-02-26 13:45:55 | MASTER-Tunka | (02h 59m 18.47s , +15d 56m 12.1s) | C | 30 | 18.8 | Coadd 11307 | 2026-02-26 13:46:17 | MASTER-Tunka | (02h 58m 51.55s , +16d 01m 36.1s) | C | 10 | 18.0 | 11307 | 2026-02-26 13:46:17 | MASTER-Tunka | (02h 59m 17.60s , +15d 57m 11.6s) | C | 10 | 17.9 | 11329 | 2026-02-26 13:46:40 | MASTER-Tunka | (02h 58m 58.52s , +16d 00m 35.7s) | C | 10 | 17.9 | 11329 | 2026-02-26 13:46:40 | MASTER-Tunka | (02h 59m 24.56s , +15d 56m 11.1s) | C | 10 | 17.9 | 11352 | 2026-02-26 13:47:03 | MASTER-Tunka | (02h 59m 18.76s , +15d 55m 10.5s) | C | 10 | 17.9 | 11362 | 2026-02-26 13:47:03 | MASTER-Tunka | (02h 59m 18.77s , +15d 55m 10.4s) | C | 30 | 18.7 | Coadd 11353 | 2026-02-26 13:47:03 | MASTER-Tunka | (02h 58m 52.73s , +15d 59m 34.6s) | C | 10 | 18.0 | 11374 | 2026-02-26 13:47:25 | MASTER-Tunka | (02h 58m 57.05s , +15d 59m 57.9s) | C | 10 | 17.9 | 11374 | 2026-02-26 13:47:25 | MASTER-Tunka | (02h 59m 23.10s , +15d 55m 33.8s) | C | 10 | 17.9 | 11400 | 2026-02-26 13:47:50 | MASTER-Tunka | (02h 58m 55.01s , +16d 01m 17.3s) | C | 10 | 17.9 | 11400 | 2026-02-26 13:47:50 | MASTER-Tunka | (02h 59m 21.06s , +15d 56m 53.3s) | C | 10 | 17.9 | 11426 | 2026-02-26 13:48:13 | MASTER-Tunka | (02h 58m 55.07s , +15d 59m 57.3s) | C | 15 | 18.2 | 11426 | 2026-02-26 13:48:13 | MASTER-Tunka | (02h 59m 21.10s , +15d 55m 33.2s) | C | 15 | 18.2 | 11441 | 2026-02-26 13:48:13 | MASTER-Tunka | (02h 59m 21.10s , +15d 55m 33.2s) | C | 45 | 19.0 | Coadd 11453 | 2026-02-26 13:48:41 | MASTER-Tunka | (02h 58m 58.09s , +16d 01m 14.6s) | C | 15 | 18.1 | 11453 | 2026-02-26 13:48:41 | MASTER-Tunka | (02h 59m 24.14s , +15d 56m 50.8s) | C | 15 | 18.1 | 11481 | 2026-02-26 13:49:08 | MASTER-Tunka | (02h 58m 51.32s , +16d 00m 32.0s) | C | 15 | 18.1 | 11481 | 2026-02-26 13:49:08 | MASTER-Tunka | (02h 59m 17.36s , +15d 56m 08.1s) | C | 15 | 18.1 | 11514 | 2026-02-26 13:49:41 | MASTER-Tunka | (02h 58m 51.83s , +16d 01m 31.0s) | C | 15 | 18.1 | 11514 | 2026-02-26 13:49:42 | MASTER-Tunka | (02h 59m 17.88s , +15d 57m 07.4s) | C | 15 | 18.1 | 11529 | 2026-02-26 13:49:42 | MASTER-Tunka | (02h 59m 17.88s , +15d 57m 07.5s) | C | 45 | 18.9 | Coadd 11542 | 2026-02-26 13:50:09 | MASTER-Tunka | (02h 58m 57.84s , +16d 00m 30.9s) | C | 15 | 18.2 | 11542 | 2026-02-26 13:50:09 | MASTER-Tunka | (02h 59m 23.88s , +15d 56m 07.4s) | C | 15 | 18.1 | 11574 | 2026-02-26 13:50:41 | MASTER-Tunka | (02h 58m 51.31s , +15d 59m 30.1s) | C | 15 | 18.2 | 11574 | 2026-02-26 13:50:41 | MASTER-Tunka | (02h 59m 17.33s , +15d 55m 06.6s) | C | 15 | 18.2 | 11604 | 2026-02-26 13:51:11 | MASTER-Tunka | (02h 58m 58.44s , +15d 59m 43.7s) | C | 15 | 18.1 | 11604 | 2026-02-26 13:51:11 | MASTER-Tunka | (02h 59m 24.49s , +15d 55m 20.3s) | C | 15 | 18.1 | 11619 | 2026-02-26 13:51:11 | MASTER-Tunka | (02h 59m 24.49s , +15d 55m 20.2s) | C | 45 | 19.0 | Coadd 11633 | 2026-02-26 13:51:40 | MASTER-Tunka | (02h 58m 55.34s , +16d 01m 27.4s) | C | 15 | 18.1 | 11633 | 2026-02-26 13:51:40 | MASTER-Tunka | (02h 59m 21.38s , +15d 57m 04.2s) | C | 15 | 18.1 | 11662 | 2026-02-26 13:52:09 | MASTER-Tunka | (02h 58m 55.45s , +15d 59m 35.4s) | C | 15 | 18.2 | 11662 | 2026-02-26 13:52:09 | MASTER-Tunka | (02h 59m 21.45s , +15d 55m 12.6s) | C | 15 | 18.1 | 11691 | 2026-02-26 13:52:38 | MASTER-Tunka | (02h 58m 57.68s , +16d 00m 59.7s) | C | 15 | 18.2 | 11691 | 2026-02-26 13:52:38 | MASTER-Tunka | (02h 59m 23.70s , +15d 56m 36.7s) | C | 15 | 18.1 | 11706 | 2026-02-26 13:52:38 | MASTER-Tunka | (02h 59m 23.70s , +15d 56m 36.7s) | C | 45 | 19.1 | Coadd 11721 | 2026-02-26 13:53:08 | MASTER-Tunka | (02h 58m 52.55s , +16d 00m 26.7s) | C | 15 | 18.2 | 11721 | 2026-02-26 13:53:08 | MASTER-Tunka | (02h 59m 18.55s , +15d 56m 04.1s) | C | 15 | 18.1 | 11751 | 2026-02-26 13:53:38 | MASTER-Tunka | (02h 58m 53.33s , +16d 01m 26.5s) | C | 15 | 18.1 | 11751 | 2026-02-26 13:53:38 | MASTER-Tunka | (02h 59m 19.32s , +15d 57m 03.9s) | C | 15 | 18.1 | 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/43847. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41960] GRB 260226A: AstroSat CZTI detection of bright long burst
by GCN Circulars 26 Feb '26

26 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43846 SUBJECT: GRB 260226A: AstroSat CZTI detection of bright long burst DATE: 26/02/26 15:00:12 GMT FROM: Anuraag Arya at IIT Bombay <aryaanuraag910(a)gmail.com> Harsha K. H. (IUCAA), M. Tembhurnikar (IUCAA), S. Salunke (IUCAA), U. Pathak (IITB), A. Arya (IITB), A. Goyal (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, bright GRB 260226A which was also detected by Fermi GBM (Fermi GBM Team, GCN Circ. 43840), Fermi LAT (Depalo et. al. , GCN Circ. 43844) and Calet (via Trigger Notices, Trig Num. 1456137494). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. Due to the extremely bright nature of the GRB, all four quadrants of CZT detectors were saturated. The strongest non-saturated peak of the lightcurve occurs at 2026-02-26 10:38:22.65 UTC. This affects the total counts and peak counts reported. The measured peak count rate associated with the burst is 2464 (+267, -180) counts/s above the background in the combined data of three quadrants (out of four), with a total of 6666 (+247, -284) counts. We caution that these numbers are impacted by the data loss from saturation. The local mean background count rate was 258 (+1, -5) counts/s. Using cumulative rates, we measure a T90 of 21 (+1, -1) s. In the preliminary analysis, we find 4947 Compton events associated with this event. The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2026-02-26 10:38:15.33 UTC. The veto detector does not show any signs of saturation. The measured peak count rate associated with the burst is 16447 (+216, -227) counts/s above the background in the combined data of all quadrants, with a total of 139460 (+832, -794) counts. The local mean background count rate was 1425 (+4, -6) counts/s. We measure a T90 of 19 (+1, -1) s from the cumulative Veto light curve. 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/43846. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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