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[vsnet-grb-info 42886] GRB 260527A/EP260527a: Glowbug gamma-ray detection
by GCN Circulars 01 Jun '26

01 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44757 SUBJECT: GRB 260527A/EP260527a: Glowbug gamma-ray detection DATE: 26/06/01 12:58:49 GMT FROM: C.C. Cheung at Naval Research Lab <Teddy.Cheung(a)nrl.navy.mil> The Glowbug gamma-ray telescope [1,2,3], operating on the International Space Station, reports the detection of GRB 260527A, which was detected initially by Einstein Probe as EP260527a (GCN 44718). The GRB was also detected by Konus-Wind (GCN 44722), GECAM-B (GCN 44724), CALET (GCN 44726), Insight-HXMT (GCN 44735), and Mars-Odyssey (HEND) with an IPN triangulation (GCN 44744). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2026-05-27 06:16:08.912 with a duration of 0.26 s and a total significance of about 40 sigma. The light curve comprises a primary peak at ~T0+0.1s and a fainter peak at ~T0+0.2s. The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS. Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS and operated until 2024 April when it was put in safe storage on orbit. Glowbug was removed from storage and resumed operation on 2025 September 12. [1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959 [2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O [3] Woolf, R.S. et al. 2024, Proc. SPIE, 13151, id. 1315108 Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/44757. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42885] Fermi GRB 260601A: Global MASTER-Net observations report
by GCN Circulars 01 Jun '26

01 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44756 SUBJECT: Fermi GRB 260601A: Global MASTER-Net observations report DATE: 26/06/01 11:45:38 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), M. Segura, 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-OAGH robotic telescope [1] located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 260601A ( Fermi GBM team, GCN 44755) errorbox 301 sec after notice time and 327 sec after trigger time at 2026-06-01 11:05:39 UT, with upper limit up to 19.5 mag. Observations started at twilight. The observations began at zenith distance = 53 deg. The sun altitude is -13.8 deg. The galactic latitude b = -18 deg., longitude l = 125 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3352995 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 357 | 2026-06-01 11:05:39 | MASTER-OAGH | (00h 50m 13.85s , +45d 57m 12.7s) | C | 60 | 19.4 | 430 | 2026-06-01 11:06:52 | MASTER-OAGH | (00h 38m 00.15s , +44d 39m 27.6s) | C | 60 | 19.1 | 430 | 2026-06-01 11:06:52 | MASTER-OAGH | (00h 48m 30.18s , +44d 02m 36.0s) | C | 60 | 19.5 | 576 | 2026-06-01 11:09:18 | MASTER-OAGH | (00h 52m 04.36s , +47d 50m 39.9s) | C | 60 | 19.0 | 678 | 2026-06-01 11:10:30 | MASTER-OAGH | (00h 59m 12.69s , +44d 07m 39.1s) | P- | 120 | 16.9 | 678 | 2026-06-01 11:10:30 | MASTER-OAGH | (01h 01m 18.88s , +43d 31m 06.4s) | P| | 120 | 17.8 | 798 | 2026-06-01 11:10:30 | MASTER-OAGH | (01h 01m 18.88s , +43d 31m 06.6s) | P| | 360 | 18.0 | Coadd 807 | 2026-06-01 11:12:39 | MASTER-OAGH | (00h 59m 19.74s , +44d 08m 01.8s) | P- | 120 | 16.9 | 807 | 2026-06-01 11:12:39 | MASTER-OAGH | (01h 01m 25.92s , +43d 31m 26.7s) | P| | 120 | 17.8 | 936 | 2026-06-01 11:14:48 | MASTER-OAGH | (00h 59m 15.81s , +44d 09m 26.1s) | P- | 120 | 16.9 | 936 | 2026-06-01 11:14:48 | MASTER-OAGH | (01h 01m 22.64s , +43d 32m 53.3s) | P| | 120 | 17.5 | 1065 | 2026-06-01 11:16:57 | MASTER-OAGH | (00h 59m 15.96s , +44d 07m 29.9s) | P- | 120 | 16.6 | 1065 | 2026-06-01 11:16:57 | MASTER-OAGH | (01h 01m 22.92s , +43d 30m 56.4s) | P| | 120 | 17.4 | 1173 | 2026-06-01 11:19:15 | MASTER-OAGH | (00h 59m 32.67s , +44d 39m 48.6s) | C | 60 | 18.5 | 1173 | 2026-06-01 11:19:15 | MASTER-OAGH | (01h 09m 59.11s , +44d 02m 59.4s) | C | 60 | 18.3 | 1246 | 2026-06-01 11:20:28 | MASTER-OAGH | (00h 57m 41.97s , +42d 45m 11.1s) | C | 60 | 18.2 | 1246 | 2026-06-01 11:20:28 | MASTER-OAGH | (01h 07m 49.03s , +42d 08m 22.9s) | C | 60 | 18.1 | 1319 | 2026-06-01 11:21:41 | MASTER-OAGH | (01h 01m 31.23s , +46d 34m 48.3s) | C | 60 | 18.1 | 1319 | 2026-06-01 11:21:41 | MASTER-OAGH | (01h 12m 18.99s , +45d 57m 59.6s) | C | 60 | 18.0 | 1393 | 2026-06-01 11:22:55 | MASTER-OAGH | (00h 55m 58.79s , +40d 51m 00.4s) | C | 60 | 17.8 | 1466 | 2026-06-01 11:24:08 | MASTER-OAGH | (00h 47m 06.39s , +42d 09m 10.0s) | C | 60 | 18.1 | 1541 | 2026-06-01 11:25:23 | MASTER-OAGH | (01h 18m 18.85s , +42d 46m 18.7s) | C | 60 | 17.2 | 1686 | 2026-06-01 11:27:48 | MASTER-OAGH | (01h 20m 55.25s , +44d 40m 22.4s) | C | 60 | 17.2 | 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/44756. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42884] GRB 260601A: Fermi GBM Final Real-time Localization
by GCN Circulars 01 Jun '26

01 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44755 SUBJECT: GRB 260601A: Fermi GBM Final Real-time Localization DATE: 26/06/01 11:10:43 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely SHORT GRB At 11:00:12 UT on 1 Jun 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260601A (trigger 802004417.438878 / 260601458). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 15.1, Dec = 44.4 (J2000 degrees, equivalent to J2000 01h 00m, 44d 23'), with a statistical uncertainty of 2.0 degrees. The angle from the Fermi LAT boresight is 30.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260601458/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260601458/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260601458/… View this GCN Circular online at https://gcn.nasa.gov/circulars/44755. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42883] GRB 260531B: GECAM-B observation
by GCN Circulars 01 Jun '26

01 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44754 SUBJECT: GRB 260531B: GECAM-B observation DATE: 26/06/01 10:08:05 GMT FROM: Xinghao Luo at IHEP <2952704891(a)qq.com> Xing-Hao Luo, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered in-flight by GRB 260531B, at 2026-05-31T13:58:00.050 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #44747). According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 12 +5/-3 s. The GECAM-B light curve can be found here: https://www.bursthub.cn//admin/static/gecambgrb260531B.png Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two micro-satellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS). View this GCN Circular online at https://gcn.nasa.gov/circulars/44754. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42882] GRB 260518B: SVOM/ECLAIRs detection of a soft burst possibly associated with EP 260518a and AT 2026ndp
by GCN Circulars 01 Jun '26

01 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44753 SUBJECT: GRB 260518B: SVOM/ECLAIRs detection of a soft burst possibly associated with EP 260518a and AT 2026ndp DATE: 26/06/01 09:04:52 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> M. Brunet, O. Godet (IRAP) report on behalf of the SVOM/ECLAIRs team The SVOM/ECLAIRs telescope detected an X-ray source starting at 2026-05-18T07:53:22 UTC (trigger time T0), labelled GRB 260518B, through an offline targeted search with the event-by-event data downloaded through the X-band ground station. The source localization is RA, Dec = 299.003 , -48.620 degrees: RA (J2000) =19h56m00.7s Dec (J2000) = -48d37m12.0s with a 90% C.L. radius of 11.1 arcmin (including a systematic error of 6 arcmin added in quadrature). This position is consistent with those of EP 260518a (Liang et al., GCN 44690) and of the optical transient AT 2026ndp with an angular separation of 1.1 and 1.0 arcmin, respectively. This event was detected within several energy ranges and timescales. The best detection is obtained by the on-ground Image Trigger with a signal-to-noise ratio of 8.2 within 4-20 keV over a time window of 40.96 seconds starting at T0-7.68 s. The burst that triggered ECLAIRs on-ground shows a multiple peak lightcurve. The burst duration is estimated to be around 52 s in the 4-20 keV energy band through imaging. The source being detected when the source was emerging from behind the Earth, ECLAIRs may have missed part of the event emission. The ECLAIRs light curve can be found here: https://docs.google.com/document/d/1DvqHDMZI5uQY-K7kINk7iSFot71MQIoEbDZZ7Yv… The time-averaged spectrum from T0-11 s to T0+41 s in the 5-120 keV energy range is best fitted by a broken powerlaw model with alpha = -1.14 +0.28/-0.26, beta = -2.98 +0.72/-1.12 and a break energy of 21.0 +3.5/-6.7 keV. With this model, the 4-120 keV fluence is (7.8 +1.6/-2.1)e-7 erg/cm^2 and the 4-120 keV photon flux is 0.63 +0.05/-0.17 ph/cm^2/s. This event is very soft and if it is a GRB, then it should be probably classified as an X-Ray Flash. Assuming a redshift of z=2.28 (Corcoran et al., GCN 44695) and a standard cosmology with H_0 = 67.3 km/s/Mpc and Omega_M = 0.315 (Planck Collaboration, 2014), we estimate the following rest-frame parameters: the isotropic energy release E_iso is (1.25 +0.27/-0.34)e+52 erg, and the rest-frame peak energy of the time-averaged spectrum Ep,z is 68.9 +11.5/-22.0 keV. With these estimates, GRB 260518B is consistent with the distribution of Type II (collapsar-like) GRBs on the Amati relation reported by Willingale et al. 2017 (figure available with the light curve). This further strengthens the nature of the event to be a Gamma-ray burst. If GRB 260518B is related to EP 260518a and the optical transient AT 2026ndp, ECLAIRs may have detected the prompt phase 5.8 h prior to the EP detection while EP and ATLAS may have observed the afterglow phase. All the quoted errors are at the 68% confidence level. The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. The SVOM/ECLAIRs point of contact for this burst is: Marius Brunet (IRAP) (marius.brunet at utoulouse.fr) View this GCN Circular online at https://gcn.nasa.gov/circulars/44753. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42881] The EP-WXT trigger 01709266272 is likely a flaring star
by GCN Circulars 01 Jun '26

01 Jun '26

TITLE: GCN CIRCULAR NUMBER: 44752 SUBJECT: The EP-WXT trigger 01709266272 is likely a flaring star DATE: 26/06/01 02:03:35 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> R.-Z. Li (YNAO, CAS), Q.-C. Liu (THU), G.-J. Yang and H.-W. Pan (NAO, CAS) on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709266272 at the time of 2026-05-31T17:22:11, is likely a stellar flare associated with StKM 1-1106 (Eclipsing Binary Candidate). The estimated flux of the flare is around 1 x 10^(-10) erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 1.4 x 10^(31) erg/s. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/44752. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42880] GRB 260531C: Fermi GBM Final Localization Correction
by GCN Circulars 31 May '26

31 May '26

TITLE: GCN CIRCULAR NUMBER: 44751 SUBJECT: GRB 260531C: Fermi GBM Final Localization Correction DATE: 26/05/31 23:57:21 GMT FROM: rhamburg(a)usra.edu The Fermi GBM team reports the detection of a likely SHORT GRB. "At 21:14:58.91 UT on 31 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260531C (trigger 801954903/260531885). This trigger was initially classified as Below Horizon by the flight software, but is in fact a GRB. The on-ground calculated location, using the Fermi GBM trigger data, is RA = 40.6, Dec = 36.2 (J2000 degrees, equivalent to J2000 2h 42m, +36d 12'), with a statistical uncertainty of 11.6 degrees. The angle from the Fermi LAT boresight is 82 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260531885/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260531885/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260531885/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/44751. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42879] Fermi Gamma-ray Burst Monitor trigger 801900520/260531256 is not a GRB
by GCN Circulars 31 May '26

31 May '26

TITLE: GCN CIRCULAR NUMBER: 44750 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 801900520/260531256 is not a GRB DATE: 26/05/31 21:26:24 GMT FROM: Eva M. Palafox at INAOE <eva.palafox(a)gmail.com> B. Mailyan (Florida Tech), E. Palafox (INAOE, Mexico) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 801900520/260531256 at 06:08:35.57 UT on 31 May 2026, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to particle activity." View this GCN Circular online at https://gcn.nasa.gov/circulars/44750. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42878] AT2026nik: EP-FXT X-ray counterpart
by GCN Circulars 31 May '26

31 May '26

TITLE: GCN CIRCULAR NUMBER: 44749 SUBJECT: AT2026nik: EP-FXT X-ray counterpart DATE: 26/05/31 21:01:15 GMT FROM: Jonathan Quirola at Radboud University <jaquirola1990(a)gmail.com> J. Quirola-Vasquez (Radboud), P. G. Jonker (Radboud), A. A. Chrimes (ESA/ESTEC), A. J. Levan (Radboud & Warwick), A Inkenhaag (Bath), D. Coppejans (Warwick), P. Groot (Radboud/UCT/SAAO): We observed the field of AT2026nik (AstroNotes: 2026-151, 2026-152) with the Follow-up X-ray Telescope (FXT) aboard the Einstein Probe mission. The observation was carried out from 2026 May 29 18:45:25.9 UT to 19:34:24.9 UT, with a total exposure time of 2.9 ks using Modules A and B. After stacking the data from both modules, we detected an X-ray source with a significance of S/N ≈ 3.4 at the position (with an uncertainty of 20"): RA = 11:22:52.6 Dec = -06:13:22.2 No X-ray source is reported at this position in the ROSAT, eROSITA, Swift-XRT, XMM-Newton, or Chandra catalogs, according to the STONKS Multi-Mission X-ray Catalog (Quintin et al. 2024). The position of the detected X-ray source is consistent with that of AT2026nik, suggesting that it is the X-ray counterpart of the transient. The source has a net count rate of 2.57e-3 counts/s. Assuming a Galactic hydrogen column density of N_H = 4e20 cm-2 and a power-law spectrum with photon index Γ = 1.5, we estimate an absorbed X-ray flux of approximately 6.1e-14 erg/cm2/s. AT2026nik exhibited a blue, nearly featureless optical spectrum (P. Pessi and J. Wise; AstroNotes: 2026-151, 2026-152), with a tentative detection of the interstellar Mg II absorption doublet at z = 0.182. Assuming this redshift, the inferred X-ray luminosity is approximately L_X~5.3e42 erg/s, consistent with that observed in AT2018cow and other LFBOTs at a similar epoch (e.g., Margutti et al. 2019). The blue optical spectrum and the newly detected X-ray counterpart support the classification of AT2026nik as a luminous fast blue optical transient (LFBOT). We thank the Einstein Probe staff for their execution of these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/44749. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42877] Fermi trigger No 801900520: Global MASTER-Net observations report
by GCN Circulars 31 May '26

31 May '26

TITLE: GCN CIRCULAR NUMBER: 44748 SUBJECT: Fermi trigger No 801900520: Global MASTER-Net observations report DATE: 26/05/31 18:30:43 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), M. Segura, 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB260531.26 (trigger No 801900520,19h 13m 33.60s , -54d 13m 12.0s, R=3.3) errorbox 2033 sec after notice time and 2082 sec after trigger time at 2026-05-31 06:43:18 UT, with upper limit up to 19.2 mag. The observations began at zenith distance = 21 deg. The sun altitude is -59.5 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB260531.26 errorbox 42758 sec after notice time and 42807 sec after trigger time at 2026-05-31 18:02:03 UT, with upper limit up to 16.5 mag. The observations began at zenith distance = 76 deg. The sun altitude is -29.8 deg. The galactic latitude b = -25 deg., longitude l = 343 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3350277 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 2113 | 2026-05-31 06:43:18 | MASTER-OAFA | (19h 11m 50.85s , -51d 54m 44.5s) | C | 60 | 18.3 | 2173 | 2026-05-31 06:43:18 | MASTER-OAFA | (19h 11m 50.85s , -51d 54m 44.5s) | C | 180 | 18.7 | Coadd 2191 | 2026-05-31 06:44:36 | MASTER-OAFA | (19h 24m 42.46s , -51d 56m 13.7s) | C | 60 | 18.1 | 2251 | 2026-05-31 06:44:36 | MASTER-OAFA | (19h 24m 42.47s , -51d 56m 13.7s) | C | 180 | 18.6 | Coadd 2272 | 2026-05-31 06:45:57 | MASTER-OAFA | (19h 24m 42.83s , -51d 55m 12.0s) | C | 60 | 18.0 | 2351 | 2026-05-31 06:47:16 | MASTER-OAFA | (19h 11m 51.26s , -51d 55m 16.0s) | C | 60 | 17.9 | 2427 | 2026-05-31 06:48:32 | MASTER-OAFA | (19h 24m 43.21s , -51d 57m 07.7s) | C | 60 | 18.0 | 2503 | 2026-05-31 06:49:48 | MASTER-OAFA | (19h 24m 50.56s , -51d 56m 49.6s) | C | 60 | 18.1 | 2563 | 2026-05-31 06:49:48 | MASTER-OAFA | (19h 24m 50.56s , -51d 56m 49.6s) | C | 180 | 18.9 | Coadd 2571 | 2026-05-31 06:50:56 | MASTER-OAFA | (19h 11m 49.05s , -51d 54m 34.6s) | C | 60 | 18.1 | 2650 | 2026-05-31 06:52:15 | MASTER-OAFA | (18h 46m 18.02s , -53d 46m 35.9s) | C | 60 | 18.1 | 2710 | 2026-05-31 06:52:15 | MASTER-OAFA | (18h 46m 18.03s , -53d 46m 35.9s) | C | 180 | 18.8 | Coadd 2724 | 2026-05-31 06:53:29 | MASTER-OAFA | (18h 46m 11.08s , -53d 47m 17.1s) | C | 60 | 18.2 | 2802 | 2026-05-31 06:54:48 | MASTER-OAFA | (18h 59m 43.87s , -53d 47m 10.3s) | C | 60 | 18.2 | 2862 | 2026-05-31 06:54:48 | MASTER-OAFA | (18h 59m 43.87s , -53d 47m 10.3s) | C | 180 | 18.8 | Coadd 2882 | 2026-05-31 06:56:07 | MASTER-OAFA | (18h 59m 50.56s , -53d 48m 08.5s) | C | 60 | 18.1 | 2965 | 2026-05-31 06:57:30 | MASTER-OAFA | (18h 46m 13.09s , -53d 48m 10.7s) | C | 60 | 18.1 | 3042 | 2026-05-31 06:58:47 | MASTER-OAFA | (18h 59m 51.14s , -53d 48m 44.6s) | C | 60 | 18.2 | 3120 | 2026-05-31 07:00:05 | MASTER-OAFA | (18h 46m 15.86s , -53d 46m 11.8s) | C | 60 | 18.0 | 3180 | 2026-05-31 07:00:05 | MASTER-OAFA | (18h 46m 15.86s , -53d 46m 11.8s) | C | 180 | 18.6 | Coadd 3199 | 2026-05-31 07:01:24 | MASTER-OAFA | (18h 46m 17.98s , -53d 46m 06.1s) | C | 60 | 18.0 | 3290 | 2026-05-31 07:02:55 | MASTER-OAFA | (18h 46m 13.31s , -53d 47m 01.3s) | C | 60 | 18.0 | 3370 | 2026-05-31 07:04:15 | MASTER-OAFA | (18h 59m 44.89s , -53d 46m 54.0s) | C | 60 | 17.8 | 3430 | 2026-05-31 07:04:15 | MASTER-OAFA | (18h 59m 44.88s , -53d 46m 54.0s) | C | 180 | 18.3 | Coadd 3450 | 2026-05-31 07:05:35 | MASTER-OAFA | (18h 59m 52.98s , -53d 47m 52.6s) | C | 60 | 17.6 | 3530 | 2026-05-31 07:06:55 | MASTER-OAFA | (18h 46m 14.94s , -53d 47m 55.3s) | C | 60 | 17.6 | 3590 | 2026-05-31 07:06:55 | MASTER-OAFA | (18h 46m 14.94s , -53d 47m 55.3s) | C | 180 | 18.0 | Coadd 3607 | 2026-05-31 07:08:12 | MASTER-OAFA | (18h 59m 52.02s , -53d 48m 41.0s) | C | 60 | 17.8 | 3684 | 2026-05-31 07:09:29 | MASTER-OAFA | (18h 46m 18.07s , -53d 46m 20.6s) | C | 60 | 17.8 | 3761 | 2026-05-31 07:10:46 | MASTER-OAFA | (18h 47m 18.97s , -51d 52m 21.5s) | C | 60 | 17.7 | 3821 | 2026-05-31 07:10:46 | MASTER-OAFA | (18h 47m 18.98s , -51d 52m 21.6s) | C | 180 | 18.4 | Coadd 3833 | 2026-05-31 07:11:58 | MASTER-OAFA | (19h 00m 10.19s , -51d 53m 44.8s) | C | 60 | 17.7 | 3893 | 2026-05-31 07:11:58 | MASTER-OAFA | (19h 00m 10.19s , -51d 53m 44.8s) | C | 180 | 18.4 | Coadd 3919 | 2026-05-31 07:13:24 | MASTER-OAFA | (19h 00m 10.57s , -51d 52m 42.2s) | C | 60 | 17.7 | 3985 | 2026-05-31 07:14:30 | MASTER-OAFA | (19h 00m 16.18s , -51d 53m 40.5s) | C | 60 | 17.9 | 4064 | 2026-05-31 07:15:49 | MASTER-OAFA | (18h 47m 13.98s , -51d 53m 47.1s) | C | 60 | 17.8 | 4141 | 2026-05-31 07:17:06 | MASTER-OAFA | (19h 00m 18.54s , -51d 54m 13.1s) | C | 60 | 18.0 | 4201 | 2026-05-31 07:17:06 | MASTER-OAFA | (19h 00m 18.54s , -51d 54m 13.1s) | C | 180 | 18.5 | Coadd 4218 | 2026-05-31 07:18:23 | MASTER-OAFA | (18h 47m 17.91s , -51d 52m 10.0s) | C | 60 | 18.1 | 4299 | 2026-05-31 07:19:44 | MASTER-OAFA | (19h 16m 32.50s , -57d 35m 27.0s) | C | 60 | 18.5 | 4359 | 2026-05-31 07:19:44 | MASTER-OAFA | (19h 16m 32.50s , -57d 35m 27.0s) | C | 180 | 19.1 | Coadd 4377 | 2026-05-31 07:21:02 | MASTER-OAFA | (19h 31m 23.40s , -57d 37m 24.8s) | C | 60 | 18.6 | 4437 | 2026-05-31 07:21:02 | MASTER-OAFA | (19h 31m 23.39s , -57d 37m 24.9s) | C | 180 | 19.2 | Coadd 4468 | 2026-05-31 07:22:33 | MASTER-OAFA | (19h 31m 23.11s , -57d 36m 22.0s) | C | 60 | 18.6 | 4547 | 2026-05-31 07:23:52 | MASTER-OAFA | (19h 16m 34.90s , -57d 36m 18.8s) | C | 60 | 18.6 | 4636 | 2026-05-31 07:25:21 | MASTER-OAFA | (19h 16m 29.15s , -57d 37m 16.0s) | C | 60 | 18.6 | 4733 | 2026-05-31 07:26:58 | MASTER-OAFA | (19h 31m 31.66s , -57d 37m 51.1s) | C | 60 | 18.7 | 4809 | 2026-05-31 07:28:14 | MASTER-OAFA | (19h 16m 32.52s , -57d 35m 30.3s) | C | 60 | 18.6 | 4869 | 2026-05-31 07:28:14 | MASTER-OAFA | (19h 16m 32.52s , -57d 35m 30.3s) | C | 180 | 19.0 | Coadd 4896 | 2026-05-31 07:29:41 | MASTER-OAFA | (19h 24m 54.82s , -51d 55m 38.1s) | C | 60 | 18.5 | 4974 | 2026-05-31 07:30:59 | MASTER-OAFA | (19h 24m 58.03s , -51d 53m 53.1s) | C | 60 | 18.4 | 5049 | 2026-05-31 07:32:14 | MASTER-OAFA | (19h 24m 52.09s , -51d 54m 46.8s) | C | 60 | 18.4 | 5109 | 2026-05-31 07:32:14 | MASTER-OAFA | (19h 24m 52.09s , -51d 54m 46.8s) | C | 180 | 19.0 | Coadd 5126 | 2026-05-31 07:33:31 | MASTER-OAFA | (19h 24m 53.16s , -51d 53m 44.0s) | C | 60 | 18.4 | 5206 | 2026-05-31 07:34:51 | MASTER-OAFA | (19h 12m 01.79s , -51d 53m 51.5s) | C | 60 | 18.3 | 5266 | 2026-05-31 07:34:51 | MASTER-OAFA | (19h 12m 01.80s , -51d 53m 51.5s) | C | 180 | 18.6 | Coadd 5288 | 2026-05-31 07:36:13 | MASTER-OAFA | (19h 12m 00.74s , -51d 54m 20.9s) | C | 60 | 17.3 | 5354 | 2026-05-31 07:37:19 | MASTER-OAFA | (19h 12m 00.96s , -51d 54m 19.5s) | C | 60 | 18.4 | 5432 | 2026-05-31 07:38:37 | MASTER-OAFA | (19h 11m 59.11s , -51d 53m 02.6s) | C | 60 | 17.8 | 5492 | 2026-05-31 07:38:37 | MASTER-OAFA | (19h 11m 59.11s , -51d 53m 02.5s) | C | 180 | 18.5 | Coadd 5499 | 2026-05-31 07:39:44 | MASTER-OAFA | (18h 59m 57.09s , -53d 47m 47.5s) | C | 60 | 18.3 | 5559 | 2026-05-31 07:39:44 | MASTER-OAFA | (18h 59m 57.09s , -53d 47m 47.5s) | C | 180 | 18.8 | Coadd 5583 | 2026-05-31 07:41:08 | MASTER-OAFA | (19h 00m 00.32s , -53d 46m 09.8s) | C | 60 | 18.1 | 5649 | 2026-05-31 07:42:14 | MASTER-OAFA | (18h 59m 54.17s , -53d 46m 49.6s) | C | 60 | 18.3 | 5728 | 2026-05-31 07:43:33 | MASTER-OAFA | (18h 59m 54.45s , -53d 45m 47.8s) | C | 60 | 17.8 | 5788 | 2026-05-31 07:43:33 | MASTER-OAFA | (18h 59m 54.45s , -53d 45m 47.7s) | C | 180 | 18.7 | Coadd 5795 | 2026-05-31 07:44:40 | MASTER-OAFA | (18h 46m 29.24s , -53d 45m 55.6s) | C | 60 | 17.8 | 5860 | 2026-05-31 07:45:46 | MASTER-OAFA | (18h 46m 23.45s , -53d 46m 53.3s) | C | 60 | 18.2 | 5920 | 2026-05-31 07:45:46 | MASTER-OAFA | (18h 46m 23.45s , -53d 46m 53.3s) | C | 180 | 18.9 | Coadd 5937 | 2026-05-31 07:47:02 | MASTER-OAFA | (18h 46m 29.93s , -53d 46m 45.6s) | C | 60 | 18.3 | 6015 | 2026-05-31 07:48:20 | MASTER-OAFA | (18h 46m 27.83s , -53d 45m 04.0s) | C | 60 | 18.2 | 6092 | 2026-05-31 07:49:38 | MASTER-OAFA | (18h 59m 59.51s , -53d 47m 11.8s) | C | 60 | 18.1 | 6159 | 2026-05-31 07:50:44 | MASTER-OAFA | (19h 00m 02.74s , -53d 45m 42.7s) | C | 60 | 18.3 | 6239 | 2026-05-31 07:52:04 | MASTER-OAFA | (18h 59m 58.05s , -53d 46m 35.6s) | C | 60 | 18.0 | 6299 | 2026-05-31 07:52:04 | MASTER-OAFA | (18h 59m 58.04s , -53d 46m 35.7s) | C | 180 | 18.6 | Coadd 6306 | 2026-05-31 07:53:11 | MASTER-OAFA | (18h 59m 57.98s , -53d 45m 33.8s) | C | 60 | 18.3 | 6395 | 2026-05-31 07:54:40 | MASTER-OAFA | (18h 46m 32.33s , -53d 45m 41.7s) | C | 60 | 18.2 | 6455 | 2026-05-31 07:54:40 | MASTER-OAFA | (18h 46m 32.33s , -53d 45m 41.7s) | C | 180 | 18.8 | Coadd 6487 | 2026-05-31 07:56:12 | MASTER-OAFA | (18h 46m 26.96s , -53d 46m 39.8s) | C | 60 | 18.2 | 6565 | 2026-05-31 07:57:30 | MASTER-OAFA | (18h 46m 33.86s , -53d 46m 12.0s) | C | 60 | 18.2 | 6642 | 2026-05-31 07:58:47 | MASTER-OAFA | (18h 46m 30.67s , -53d 44m 47.0s) | C | 60 | 18.0 | 6702 | 2026-05-31 07:58:47 | MASTER-OAFA | (18h 46m 30.67s , -53d 44m 47.0s) | C | 180 | 17.8 | Coadd 6720 | 2026-05-31 08:00:05 | MASTER-OAFA | (19h 00m 24.77s , -51d 53m 14.9s) | C | 60 | 18.1 | 6800 | 2026-05-31 08:01:25 | MASTER-OAFA | (19h 00m 27.28s , -51d 51m 36.1s) | C | 60 | 18.1 | 6876 | 2026-05-31 08:02:41 | MASTER-OAFA | (19h 00m 21.83s , -51d 52m 26.9s) | C | 60 | 18.1 | 6936 | 2026-05-31 08:02:41 | MASTER-OAFA | (19h 00m 21.84s , -51d 52m 27.0s) | C | 180 | 18.0 | Coadd 6952 | 2026-05-31 08:03:57 | MASTER-OAFA | (19h 00m 22.92s , -51d 51m 25.9s) | C | 60 | 18.0 | 7030 | 2026-05-31 08:05:15 | MASTER-OAFA | (18h 47m 31.26s , -51d 51m 37.6s) | C | 60 | 18.0 | 7090 | 2026-05-31 08:05:15 | MASTER-OAFA | (18h 47m 31.26s , -51d 51m 37.5s) | C | 180 | 18.6 | Coadd 7109 | 2026-05-31 08:06:34 | MASTER-OAFA | (18h 47m 26.86s , -51d 52m 35.5s) | C | 60 | 18.0 | 7185 | 2026-05-31 08:07:50 | MASTER-OAFA | (18h 47m 33.69s , -51d 52m 33.5s) | C | 60 | 17.9 | 7262 | 2026-05-31 08:09:07 | MASTER-OAFA | (18h 47m 30.42s , -51d 50m 54.8s) | C | 60 | 18.0 | 7341 | 2026-05-31 08:10:26 | MASTER-OAFA | (19h 31m 38.78s , -57d 36m 37.1s) | C | 60 | 18.4 | 7401 | 2026-05-31 08:10:26 | MASTER-OAFA | (19h 31m 38.78s , -57d 36m 37.2s) | C | 180 | 19.2 | Coadd 7423 | 2026-05-31 08:11:48 | MASTER-OAFA | (19h 31m 41.47s , -57d 35m 19.3s) | C | 60 | 18.5 | 7499 | 2026-05-31 08:13:04 | MASTER-OAFA | (19h 31m 37.44s , -57d 35m 53.0s) | C | 60 | 18.5 | 7576 | 2026-05-31 08:14:22 | MASTER-OAFA | (19h 31m 37.85s , -57d 34m 50.7s) | C | 60 | 18.5 | 7636 | 2026-05-31 08:14:22 | MASTER-OAFA | (19h 31m 37.78s , -57d 34m 50.9s) | C | 180 | 18.6 | Coadd 7654 | 2026-05-31 08:15:39 | MASTER-OAFA | (19h 16m 47.51s , -57d 34m 53.5s) | C | 60 | 18.4 | 7746 | 2026-05-31 08:17:11 | MASTER-OAFA | (19h 16m 43.21s , -57d 35m 51.2s) | C | 60 | 18.4 | 7834 | 2026-05-31 08:18:39 | MASTER-OAFA | (19h 16m 49.04s , -57d 35m 26.2s) | C | 60 | 18.3 | 7914 | 2026-05-31 08:19:59 | MASTER-OAFA | (19h 16m 46.29s , -57d 34m 03.8s) | C | 60 | 18.2 | 8005 | 2026-05-31 08:21:30 | MASTER-OAFA | (19h 25m 06.71s , -51d 54m 22.7s) | C | 60 | 18.3 | 8095 | 2026-05-31 08:23:00 | MASTER-OAFA | (19h 25m 09.34s , -51d 52m 44.0s) | C | 60 | 18.2 | 8155 | 2026-05-31 08:23:00 | MASTER-OAFA | (19h 25m 09.34s , -51d 52m 44.0s) | C | 180 | 18.8 | Coadd 8183 | 2026-05-31 08:24:28 | MASTER-OAFA | (19h 25m 03.90s , -51d 53m 26.1s) | C | 60 | 18.2 | 8265 | 2026-05-31 08:25:50 | MASTER-OAFA | (19h 25m 04.32s , -51d 52m 24.1s) | C | 60 | 18.1 | 8331 | 2026-05-31 08:26:57 | MASTER-OAFA | (19h 12m 14.55s , -51d 52m 37.2s) | C | 60 | 18.0 | 8408 | 2026-05-31 08:28:13 | MASTER-OAFA | (19h 12m 09.06s , -51d 53m 35.4s) | C | 60 | 18.0 | 8493 | 2026-05-31 08:29:38 | MASTER-OAFA | (19h 12m 13.79s , -51d 53m 04.8s) | C | 60 | 18.0 | 8572 | 2026-05-31 08:30:57 | MASTER-OAFA | (19h 12m 12.05s , -51d 51m 59.9s) | C | 60 | 18.0 | 8654 | 2026-05-31 08:32:19 | MASTER-OAFA | (19h 00m 11.05s , -53d 46m 14.3s) | C | 60 | 18.0 | 8746 | 2026-05-31 08:33:51 | MASTER-OAFA | (19h 00m 13.99s , -53d 45m 00.1s) | C | 60 | 17.9 | 8806 | 2026-05-31 08:33:51 | MASTER-OAFA | (19h 00m 13.99s , -53d 45m 00.1s) | C | 180 | 18.5 | Coadd 8836 | 2026-05-31 08:35:21 | MASTER-OAFA | (19h 00m 09.05s , -53d 45m 39.9s) | C | 60 | 17.9 | 8911 | 2026-05-31 08:36:36 | MASTER-OAFA | (19h 00m 08.70s , -53d 44m 38.2s) | C | 60 | 17.9 | 9004 | 2026-05-31 08:38:09 | MASTER-OAFA | (18h 46m 44.75s , -53d 44m 51.5s) | C | 60 | 17.7 | 9114 | 2026-05-31 08:39:59 | MASTER-OAFA | (18h 46m 30.23s , -53d 52m 59.6s) | C | 60 | 17.8 | 9180 | 2026-05-31 08:41:05 | MASTER-OAFA | (18h 46m 36.47s , -53d 52m 41.7s) | C | 60 | 17.9 | 9261 | 2026-05-31 08:42:26 | MASTER-OAFA | (18h 46m 34.22s , -53d 51m 00.2s) | C | 60 | 17.9 | 9350 | 2026-05-31 08:43:55 | MASTER-OAFA | (19h 00m 07.00s , -53d 53m 37.7s) | C | 60 | 16.4 | 9410 | 2026-05-31 08:43:55 | MASTER-OAFA | (19h 00m 07.00s , -53d 53m 37.7s) | C | 180 | 17.9 | Coadd 9497 | 2026-05-31 08:46:23 | MASTER-OAFA | (19h 00m 04.66s , -53d 52m 39.3s) | C | 60 | 17.5 | 9578 | 2026-05-31 08:47:43 | MASTER-OAFA | (19h 00m 04.92s , -53d 51m 38.1s) | C | 60 | 17.9 | 9662 | 2026-05-31 08:49:07 | MASTER-OAFA | (19h 00m 33.52s , -51d 59m 01.0s) | C | 60 | 17.9 | 9740 | 2026-05-31 08:50:25 | MASTER-OAFA | (19h 00m 30.52s , -51d 57m 57.7s) | C | 60 | 18.0 | 9800 | 2026-05-31 08:50:25 | MASTER-OAFA | (19h 00m 30.51s , -51d 57m 57.7s) | C | 180 | 18.6 | Coadd 9824 | 2026-05-31 08:51:49 | MASTER-OAFA | (19h 00m 30.70s , -51d 59m 13.4s) | C | 60 | 18.0 | 9902 | 2026-05-31 08:53:07 | MASTER-OAFA | (19h 00m 33.85s , -51d 57m 39.7s) | C | 60 | 18.1 | 9989 | 2026-05-31 08:54:34 | MASTER-OAFA | (19h 31m 49.04s , -57d 42m 31.4s) | C | 60 | 18.5 | 10064 | 2026-05-31 08:55:50 | MASTER-OAFA | (19h 31m 42.78s , -57d 43m 30.9s) | C | 60 | 18.4 | 10144 | 2026-05-31 08:57:09 | MASTER-OAFA | (19h 31m 49.15s , -57d 43m 13.2s) | C | 60 | 17.6 | 10217 | 2026-05-31 08:58:22 | MASTER-OAFA | (19h 31m 47.05s , -57d 41m 44.9s) | C | 60 | 18.3 | 10309 | 2026-05-31 08:59:55 | MASTER-OAFA | (19h 25m 08.75s , -51d 59m 40.0s) | C | 60 | 18.2 | 10369 | 2026-05-31 08:59:55 | MASTER-OAFA | (19h 25m 08.75s , -51d 59m 40.0s) | C | 180 | 18.7 | Coadd 10392 | 2026-05-31 09:01:17 | MASTER-OAFA | (19h 25m 08.62s , -51d 58m 38.4s) | C | 60 | 18.1 | 10477 | 2026-05-31 09:02:42 | MASTER-OAFA | (19h 25m 14.18s , -51d 59m 37.6s) | C | 60 | 17.8 | 10546 | 2026-05-31 09:03:51 | MASTER-OAFA | (19h 25m 08.91s , -52d 00m 36.7s) | C | 60 | 17.7 | 10667 | 2026-05-31 09:05:53 | MASTER-OAFA | (19h 02m 08.96s , -50d 04m 19.5s) | C | 60 | 18.0 | 10746 | 2026-05-31 09:07:11 | MASTER-OAFA | (19h 02m 02.62s , -50d 05m 18.5s) | C | 60 | 17.9 | 10843 | 2026-05-31 09:08:48 | MASTER-OAFA | (19h 36m 55.75s , -51d 59m 09.3s) | C | 60 | 18.3 | 10903 | 2026-05-31 09:08:48 | MASTER-OAFA | (19h 36m 55.75s , -51d 59m 09.3s) | C | 180 | 18.9 | Coadd 10919 | 2026-05-31 09:10:04 | MASTER-OAFA | (19h 36m 49.81s , -52d 00m 06.7s) | C | 60 | 18.2 | 11010 | 2026-05-31 09:11:35 | MASTER-OAFA | (19h 36m 49.96s , -52d 00m 05.7s) | C | 60 | 18.4 | 11102 | 2026-05-31 09:13:07 | MASTER-OAFA | (19h 36m 50.16s , -52d 00m 04.8s) | C | 60 | 18.5 | 11162 | 2026-05-31 09:13:07 | MASTER-OAFA | (19h 36m 50.16s , -52d 00m 04.8s) | C | 180 | 19.2 | Coadd 11270 | 2026-05-31 09:15:55 | MASTER-OAFA | (19h 36m 56.81s , -52d 00m 59.2s) | C | 60 | 18.4 | 11348 | 2026-05-31 09:17:13 | MASTER-OAFA | (19h 36m 54.49s , -52d 00m 45.3s) | C | 60 | 18.4 | 11599 | 2026-05-31 09:21:24 | MASTER-OAFA | (19h 36m 53.46s , -51d 58m 57.5s) | C | 60 | 18.3 | 11659 | 2026-05-31 09:21:24 | MASTER-OAFA | (19h 36m 53.46s , -51d 58m 57.5s) | C | 180 | 19.0 | Coadd 11677 | 2026-05-31 09:22:43 | MASTER-OAFA | (19h 36m 57.97s , -51d 59m 57.0s) | C | 60 | 18.2 | 11824 | 2026-05-31 09:25:09 | MASTER-OAFA | (19h 36m 58.67s , -52d 00m 50.4s) | C | 60 | 18.2 | 42838 | 2026-05-31 18:02:03 | MASTER-SAAO | (19h 12m 51.00s , -50d 21m 54.7s) | C | 60 | 16.2 | 42838 | 2026-05-31 18:02:03 | MASTER-SAAO | (19h 10m 01.45s , -50d 06m 26.3s) | C | 60 | 16.5 | 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/44748. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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