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

[vsnet-grb-info 41739] GRB 260208A: Fermi GBM Final Real-time Localization
by GCN Circulars 08 Feb '26

08 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43635 SUBJECT: GRB 260208A: Fermi GBM Final Real-time Localization DATE: 26/02/08 05:18:10 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 05:07:28 UT on 8 Feb 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260208A (trigger 792220053.24286 / 260208214). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 204.4, Dec = 33.0 (J2000 degrees, equivalent to J2000 13h 37m, 33d 00'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 79.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260208214/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260208214/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260208214/… View this GCN Circular online at https://gcn.nasa.gov/circulars/43635. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41738] GRB 260207B: Fermi GBM Detection of a Short Burst with Extended Emission
by GCN Circulars 08 Feb '26

08 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43634 SUBJECT: GRB 260207B: Fermi GBM Detection of a Short Burst with Extended Emission DATE: 26/02/08 04:24:37 GMT FROM: Rushikesh Sonawane at IISER, TVM <rushikesh23(a)iisertvm.ac.in> R. Sonawane (IISER, TVM) and S. Bala (USRA) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 13:12:10.83 UT on 07 February 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260207B (trigger 792162735/260207550). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 292.87, Dec = 50.03 (J2000 degrees, equivalent to J2000 19h 31m, +50d 1'), with a statistical uncertainty of 2.81 degrees. (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a mixture of two Gaussians, one with a radius of 1.8 degrees (52% contribution) and one with a radius of 4.1 degrees (47% contribution) [A. Goldstein et al. 2020, ApJ, 895, 1]). The angle from the Fermi LAT boresight is 45 degrees. The GBM light curve consists of a short spike (Main Emission, ME) followed by an extended emission (EE) with a total duration (T90) of about 56 s (50-300 keV). The ME from T0-1 to T0+5 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.18 +/- 0.07 and the cutoff energy, parameterized as Epeak, is 350 +/- 65 keV. The total fluence (10-1000 keV) in this time interval is (2.7 +/- 0.1)E-06 erg/cm^2. The EE from T0+10 to T0+89 s, is best fit by a Band function with Epeak= 32 +/- 4 keV, alpha = -1.7 +/- 0.1 and beta = -2.4 +/- 0.1. The total fluence (10-1000 keV) during this time interval is (7.5 +/- 0.4)E-06 erg/cm^2. The time-averaged (ME+EE) spectrum from T0-2 to T0+89 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.83 +/- 0.05 and the cutoff energy, parameterized as Epeak, is 67 +/- 9 keV. A Band function fits this interval equally well with Epeak= 52 +/- 10 keV, alpha = -1.7 +/- 0.1 and beta = -2.2 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (9.6 +/- 0.5)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.0024 s in the 10-1000 keV band is 16.6 +/- 0.3 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/43634. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41737] GRB 260207A : MASTER optical counterpart discovery
by GCN Circulars 07 Feb '26

07 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43633 SUBJECT: GRB 260207A : MASTER optical counterpart discovery DATE: 26/02/07 19:42:05 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> C. Francile (OAFA), O.Gress (ISU), V.M.Lipunov (Lomonosov MSU), R.Podesta, F.Podesta (OAFA), D.Svinkin, A.Ridnaya (Ioffe Institute), I.Panchenko, P.Balanutsa, G.Antipov, A.Kuznetsov, E.Gorbovskoy, N. Tiurina, Ya.Kechin,A.Chasovnikov, V.A.Senik, D.Vlasenko, I.Ionov,Yu.Tselik(Lomonosov MSU), N.Budnev, R.Mirgazov, A.Diachok, O.Ershova (Irkutsk State University), E. Gonzalez (OAFA, San JuanUni.,Argentina); D.Buckley (SAAO), A. Sosnovskij (CrAO RAS), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino, J.Martinez, A.R.Corella, J.G. Tanori, L. F. Villalobos, L.H.Rodriguez (INAOE, Guillermo Haro AstrophysicObservatory, Mexico) V.M.Pillet, R.Rebolo Lopez (The Instituto de Astrofisica de Canarias,Spain) MASTER Global Robotic Net started (Lipunov et al. GCN 43627) Fermi GRB 260207A (GCN 43628) alert observtions at MASTER-OAFA 110 sec after notice time and 142 sec after trigger time at 2026-02-07 05:44:56 UT MASTER OT J104411.31-330936.2 discovery V.Lipunov (Lomonosov MSU), E.Gorbovskoy, N.Tiurina, P.Balanutsa, A.Kuznetsov, V.Kornilov, O.Gress, K.Ivanov, V.Vladimirov, D.Kuvshinov (Lomonosov Moscow State University, SAI) MASTER-OAFA auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 10h 44m 11.31s -33d 09m 36.2s on 2026-02-07.24049 UT. The OT unfiltered magnitude was 17.3m(mlim19.8=). The OT is seen in 27 images with typical decay with different features at light curves. There is no minor planet at this place. We have reference image on 2025-02-08.36365 UT with unfiltered 20.1m. Deep photometry and spectral observations are required. We reobserved this coordinates at MASTER-SAAO at 2026-02-07 18:59:00 without object, that confirmed GRBoptical counterpart nature View this GCN Circular online at https://gcn.nasa.gov/circulars/43633. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41736] GRB 260131A/B: Mondy and Terskol optical observations
by GCN Circulars 07 Feb '26

07 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43632 SUBJECT: GRB 260131A/B: Mondy and Terskol optical observations DATE: 26/02/07 15:36:31 GMT FROM: Alina Volnova at IKI RAS <alinusss(a)gmail.com> A. Volnova (IKI), E. Klunko (ISTP), I. Sokolov (INASAN, KIAM), N. Pankov (IKI), A. Pozanenko (IKI) report on behalf of IKI-GRB-FuN: We observed the field of GRB 260131A/B (Fermi GBM Team, GCN 43579; Sugai et al., GCN 43580; Roberts et al., GCN 43585; Frederiks et al., GCN 43590; Luo et al., GCN 43591; Jiang et al., GCN 43600; Li et al., GCN 43605) with the AZT-33IK 1.5m telescope of the Mondy observatory on Feb. 4 and 5, and with the 2-meter Zeiss-2000 telescope of the Terskol observatory on Feb. 4 taking several frames in the R band. The optical counterpart reported by Gompertz et al., GCN 43586; Lee et al., GCN 43587; Saccardi et al., GCN 43595; García García et al., GCN 43599, Shi et al., GCN 43601; Sanchez-Ramirez et al., GCN 43604; Jayaraman et al., GCN 43606; Zhu et al., GCN 43607; Zheng et al., GCN 43609; Adami et al., GCN 43610, is detected in the stacked frame of every epoch. Preliminary photometry and observation data are the following: Date UT start t-T0 Exp. Filter Obj. Err. UL Site/Telescope (mid,days) (n*s) (3sigma) 2026-02-04 12:10:33 4.26118 43*120 R 19.56 0.04 22.3 Mondy/AZT-33IK 2026-02-04 15:54:04 4.41278 30*150 R 19.87 0.07 22.2 Zeiss-2000/Terskol 2026-02-05 13:40:24 5.32702 49*120 R 19.83 0.04 22.5 Mondy/AZT-33IK The photometry is based on several nearby stars from the USNO-B1 catalogue (R2 magnitudes) and is not corrected for the Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/43632. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41735] Fermi GRB 260207B: Global MASTER-Net observations report
by GCN Circulars 07 Feb '26

07 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43631 SUBJECT: Fermi GRB 260207B: Global MASTER-Net observations report DATE: 26/02/07 15:30:40 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-Kislovodsk robotic telescope [1] located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 260207B ( Fermi GBM team, GCN 43629) errorbox 7553 sec after notice time and 7584 sec after trigger time at 2026-02-07 15:18:35 UT, with upper limit up to 13.0 mag. Observations started at twilight. The observations began at zenith distance = 74 deg. The sun altitude is -9.3 deg. The galactic latitude b = 14 deg., longitude l = 82 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3125301 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 7614 | 2026-02-07 15:18:35 | MASTER-Kislovodsk | (19h 15m 56.41s , +48d 54m 29.6s) | C | 60 | 13.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/43631. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41734] GRB 260206A: Swift-XRT observations
by GCN Circulars 07 Feb '26

07 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43630 SUBJECT: GRB 260206A: Swift-XRT observations DATE: 26/02/07 14:08:50 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> S. Lanava (PSU), S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the MAXI-detected burst GRB 260206A (Negoro et al. GCN Circ. 43624) in a series of observations tiled on the sky. The total exposure time is 1.6 ks, distributed over 5 tiles; the maximum exposure at a single sky location in the tiling was 787 s. The data were collected between T0+32.1 ks and T0+38.5 ks, and are entirely in Photon Counting (PC) mode. One uncatalogued X-ray source has been detected, with a rank of "reasonable" (i.e. a ~2 sigma detection); however, it is neither above historical upper limits nor shows evidence of fading. Therefore, at the present time we cannot say whether or not it is the afterglow. The source details are: Source 3: RA (J2000.0): 78.4839 = 05h 13m 56.13s Dec (J2000.0): -40.5311 = -40d 31' 51.8" Error: 6.7 arcsec (radius, 90% conf.) Count-rate: 0.0117 [+0.0077, -0.0055] ct s^-1 Distance: 523 arcsec from MAXI position. Two catalogued sources were also detected, including the LMXB 4U 0513-40 noted by Negoro et al. (GCN Circ. 43624); as well two 'poor' sources (~1 sigma detections). The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00142. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/43630. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41733] GRB 260207B: Fermi GBM Final Real-time Localization
by GCN Circulars 07 Feb '26

07 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43629 SUBJECT: GRB 260207B: Fermi GBM Final Real-time Localization DATE: 26/02/07 13:22:56 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 13:12:10 UT on 7 Feb 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260207B (trigger 792162735.829288 / 260207550). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 292.9, Dec = 50.0 (J2000 degrees, equivalent to J2000 19h 31m, 50d 00'), with a statistical uncertainty of 2.8 degrees. The angle from the Fermi LAT boresight is 45.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260207550/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260207550/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260207550/… View this GCN Circular online at https://gcn.nasa.gov/circulars/43629. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41732] GRB 260207A: Fermi GBM Final Localization
by GCN Circulars 07 Feb '26

07 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43628 SUBJECT: GRB 260207A: Fermi GBM Final Localization DATE: 26/02/07 06:32:02 GMT FROM: Rushikesh Sonawane at IISER, TVM <rushikesh23(a)iisertvm.ac.in> The Fermi GBM team reports the detection of a likely LONG GRB "At 05:42:33.65 UT on 07 February 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260207A (trigger 792135758/260207238). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 160.45, Dec = -34.44 (J2000 degrees, equivalent to J2000 10h 41m, -34d 26'), with a statistical uncertainty of 3.29 degrees. The angle from the Fermi LAT boresight is 37 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260207238/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260207238/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260207238/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/43628. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41731] Fermi trigger No 792135758: Global MASTER-Net observations report
by GCN Circulars 07 Feb '26

07 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43627 SUBJECT: Fermi trigger No 792135758: Global MASTER-Net observations report DATE: 26/02/07 06:16:25 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB260207.24 (trigger No 792135758,10h 41m 48.00s , -34d 26m 24.0s, R=3.29) errorbox 110 sec after notice time and 142 sec after trigger time at 2026-02-07 05:44:56 UT, with upper limit up to 20.7 mag. The observations began at zenith distance = 7 deg. The sun altitude is -41.7 deg. The galactic latitude b = 21 deg., longitude l = 275 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3124959 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 158 | 2026-02-07 05:44:56 | MASTER-OAFA | (10h 51m 33.24s , -33d 38m 46.3s) | C | 30 | 19.5 | 203 | 2026-02-07 05:44:56 | MASTER-OAFA | (10h 51m 33.24s , -33d 38m 46.4s) | C | 120 | 20.0 | Coadd 198 | 2026-02-07 05:45:32 | MASTER-OAFA | (10h 51m 33.30s , -33d 38m 44.9s) | C | 40 | 19.6 | 250 | 2026-02-07 05:46:18 | MASTER-OAFA | (10h 51m 33.38s , -33d 38m 43.0s) | C | 50 | 19.7 | 311 | 2026-02-07 05:47:14 | MASTER-OAFA | (10h 51m 33.48s , -33d 38m 40.8s) | C | 60 | 19.8 | 382 | 2026-02-07 05:48:20 | MASTER-OAFA | (10h 51m 33.59s , -33d 38m 38.3s) | C | 70 | 19.8 | 644 | 2026-02-07 05:52:17 | MASTER-OAFA | (10h 42m 03.76s , -34d 05m 23.7s) | C | 120 | 19.9 | 799 | 2026-02-07 05:52:17 | MASTER-OAFA | (10h 42m 03.76s , -34d 05m 23.7s) | C | 430 | 20.7 | Coadd 781 | 2026-02-07 05:54:24 | MASTER-OAFA | (10h 42m 04.00s , -34d 05m 19.4s) | C | 140 | 19.9 | 942 | 2026-02-07 05:56:50 | MASTER-OAFA | (10h 42m 04.28s , -34d 05m 14.5s) | C | 170 | 19.9 | 1064 | 2026-02-07 05:59:47 | MASTER-OAFA | (10h 42m 04.50s , -34d 05m 10.9s) | C | 60 | 19.7 | 1129 | 2026-02-07 06:00:52 | MASTER-OAFA | (10h 42m 04.62s , -34d 05m 08.8s) | C | 60 | 19.7 | 1194 | 2026-02-07 06:01:58 | MASTER-OAFA | (10h 42m 04.73s , -34d 05m 07.0s) | C | 60 | 19.7 | 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/43627. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41730] EP260131a: VLA detection
by GCN Circulars 06 Feb '26

06 Feb '26

TITLE: GCN CIRCULAR NUMBER: 43626 SUBJECT: EP260131a: VLA detection DATE: 26/02/06 20:32:30 GMT FROM: Genevieve Schroeder at Cornell University <genevieveschroeder(a)u.northwestern.edu> Genevieve Schroeder (Cornell), Anna Ho (Cornell), Daniel Perley (LJMU) report: We observed the position of EP260131a (Ding et al., GCN 43574, Wu et al. GCN 43583), with the Karl G. Jansky Very Large Array (VLA) under program 26A-488 (PI: Ho) beginning on 2026 February 3 at 06:37 UT (3.15 days post discovery) at a mean frequency of 10 GHz. Based on preliminary analysis, we detect a ~40 uJy (~6 sigma) radio source at the position of EP260131a. At the assumed redshift of EP260131a of z = 0.937 (Schneider et al., GCN 43582), the VLA observation corresponds to a 10 GHz luminosity of ~1e30 erg/s/Hz. This is consistent with, but on the lower end of, a typical GRB radio afterglow (Chandra & Frail 2012, ApJ, 746, 156). Additional followup is planned. We thank the VLA staff for quickly approving and executing these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/43626. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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