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

[vsnet-grb-info 43639] GRB 260818B: VLA radio observations
by GCN Circulars 21 Aug '26

21 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45418 SUBJECT: GRB 260818B: VLA radio observations DATE: 26/08/21 22:41:23 GMT FROM: Genevieve Schroeder at Cornell University <genevieveschroeder(a)u.northwestern.edu> G. Schroeder (U. Toronto), W. Fong (Northwestern), J. Rastinejad (UMD) report: We observed the location of the short-duration GRB 260818B (Cordier et al., GCN 45398; Wang et al., GCN 45408; Ren et al, GCN 45411) with the Karl G. Jansky Very Large Array (VLA) in D configuration under program 26A-062 (PI Schroeder) for two 0.75 hour epochs at a mean frequency of 6 GHz and mid times of 2026 Aug 20 at 07:58 UT (1.5 days post-burst) and 2026 Aug 21 at 11:23 UT (2.6 days post-burst). The images reached typical rms values of 7-10 uJy. In preliminary analysis, we detect 13 >= 5-sigma radio sources within the ECLAIRs error region across both epochs. Of them, 9 appear to vary on the 1 sigma level across the two epochs, only 1 of which appears to have faded by 3 sigma across the two epochs (S3). The details of the variable sources are as follows: | Source | R.A.| Dec. | Error (arcsec) | Fnu e1 (uJy) | Fnu e2 (uJy) | Notes | | ------------ | ------------ | ------------ | ------------ | ------------ | ------------ | ------------ | | S2 | 02:59:56.59 | +07:29:28.5 | 2.3 | 83 | 107 | Close to apparent galaxy | | S3 | 02:59:36.59 | +07:28:16.0 | 3.0 | 96 | 34 | Faded by >= 3sigma | | S4 | 02:59:51.45 | +07:27:41.8 | 5.2 | 63 | 90 | Close to apparent galaxy | | S5 | 03:00:00.19 | +07:27:23.4 | 0.4 | 1266 | 1200 | In VLASS/RACS | | S7 | 02:59:38.44 | +07:26:20.5 | 2.7 | 114 | 91 | | | S8 | 02:59:49.96 | +07:25:46.9 | 3.5 | 168 | 110 | | | S9 | 02:59:50.37 | +07:25:41.0 | 4.0 | 169 | 91 | | | S10 | 02:59:54.25 | +07:25:28.7 | 0.3 | 1232 | 1139 | Coincident with EPF_J025955.0+072535, in VLASS/RACS | | S11 | 02:59:44.77 | +07:25:25.0 | 1.1 | 200 | 178 | Close to apparent galaxy | Additionally, we note that EPF_J025955.0+072535 and EPF_J025936.6+072418 (Wu et al., GCN 45407) are coincident with long-lived radio sources present in VLASS and RACS (which are present in our observations as well). There is a faint radio source coincident with EPF_J025951.6+072917, however the flux density doesn’t vary significantly over the two epochs (~50 uJy). We thank the VLA staff for quickly approving and executing these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/45418. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43638] GRB 260818B: SVOM/C-GFT optical upper limit
by GCN Circulars 21 Aug '26

21 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45417 SUBJECT: GRB 260818B: SVOM/C-GFT optical upper limit DATE: 26/08/21 16:21:24 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Y.X Guan(GXU), Z. Kang (CHO), C. Wu , L.P. Xin, X.H. Han, P.P. Zhang, X.M. Lu (NAOC), Z.W. Li, Y. Lv (CHO), R.S. Zhang, Y.J. Xiao, Y.L. Qiu, J. Wang, J.S. Deng, L. Huang, J.Y. Wei (NAOC), Bertrand Cordier (CEA), Hatsune Goto (RIKEN, CEA) , report on behalf of the SVOM/C-GFT team: We observed the field of GRB 260818B detected by SVOM/ECLAIRs (Bertrand Cordier et al., GCN 45398)， HXMT (Wang et al., GCN 45408), and SVOM/GRM (Ren et al., GCN 45411) with LATIOS on SVOM/C-GFT. Observations started at 2026-08-20T17:09:40.28 UTC, ~1.87 days after the trigger. We obtained i-band follow-up imaging. After preliminary analysis, no credible candidate was detected within the error box provided by EP-FXT (Wu et al., GCN 45407) in our images. We measure the following upper limit calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction: i > 19.9 AB (3-sigma, mid-time 1.88 days after the trigger). This is consistent with the non-detection reported by Shi et al.(GCN 45399) and Neill et al.(GCN 45403) We thank the observation assistants Y.-H. Hao and C.-L. Guo at Jilin observatory for their excellent support. The Chinese Ground Follow-up Telescope (C-GFT) for the SVOM mission is located at Jilin Station, Changchun Observatory, National Astronomical Observatories, CAS. It features two instruments: (1) CATCH at the Cassegrain focus with a 21 arcmin x 21 arcmin FOV for simultaneous g/r/i-band imaging, and (2) LATIOS, a 4k x 4k CMOS camera at the prime focus with a 1.28 deg x 1.28 deg FOV that images in g, r, and i bands via filter switching. View this GCN Circular online at https://gcn.nasa.gov/circulars/45417. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43637] EP260731a: SVOM/ECLAIRs detection through offline targeted search
by GCN Circulars 21 Aug '26

21 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45416 SUBJECT: EP260731a: SVOM/ECLAIRs detection through offline targeted search DATE: 26/08/21 13:10:00 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> H. Yang, S. Guillot, O. Godet (IRAP) report on behalf of the SVOM team: The SVOM/ECLAIRs telescope detected EP260731a (EP team, GCN 45261), starting at 2026-07-31T00:53:19 UTC (T0), through an offline targeted search with the event-by-event data downloaded via the X-band ground station. The ECLAIRs detection, at T0, occurred 31 s before the EP-WXT detection that began at 2026-07-31T00:53:50 UTC (EP team, GCN 45301). The burst was detected within several timescales and energy ranges. The best detection is obtained by the image trigger with a signal-to-noise ratio of 6.4 within 8-120 keV over a time window of 82 s starting at T0. This event was not detected onboard because it was too faint. The localization of the source is RA, Dec = 344.500, -11.872 degrees: RA (J2000) = 22h58m00s Dec (J2000) = -11d52m19s with a 90% C.L. radius of 12.14 arcmin (including systematic error of 2 arcmin added in quadrature). This position is consistent with that measured by EP/FXT, with an angular separation of 7.8 arcmin. The ECLAIRs lightcurve shows a multi-peaked structure lasting around 82 s in the 4 - 120 keV band. The time-averaged spectrum from T0 to T0+82 s in the 5-120 keV is well fitted by a power law with a photon index of -1.4 +/- 0.2, a 4-120 keV photon flux of 0.22 +0.02/-0.06 photons/cm^2/s, and a corresponding 4-120 keV fluence of (7 +/- 1)e-7 erg/cm^2. Using the same extraction time window from T0+31 s to T0+66 s as EP/WXT, the time-averaged spectrum in the 5-120 keV is also well fitted by a power law with a photon index of -1.4 +/- 0.2, a 4-120 keV photon flux of 0.28 +0.02/-0.08 photons/cm^2/s, and a corresponding 4-120 keV fluence of (3.7 +/- 0.8)e-7 erg/cm^2. The spectral properties measured with SVOM/ECLAIRs are broadly consistent with those reported by EP/WXT (EP team, GCN 45301). All quoted errors are at the 68% confidence level. The Space 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 APC, CEA, CNES, and IRAP. The SVOM/ECLAIRs point of contact for this event is : Hui Yang (hui.yang(a)cnrs.fr) Please contact him by email if you require additional information regarding the SVOM follow-up of this burst. View this GCN Circular online at https://gcn.nasa.gov/circulars/45416. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43636] IceCube Alert 260821A: Global MASTER-Net observations report
by GCN Circulars 21 Aug '26

21 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45415 SUBJECT: IceCube Alert 260821A: Global MASTER-Net observations report DATE: 26/08/21 10:27:04 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) was pointed to the IceCube Alert 260821A (trigger No 51776820,07h 44m 40.80s , +10d 03m 00.0s, R=0.46) errorbox 22610 sec after notice time and 22930 sec after trigger time at 2026-08-21 09:56:59 UT, with upper limit up to 16.5 mag. Observations started at twilight. The observations began at zenith distance = 76 deg. The sun altitude is -15.2 deg. The galactic latitude b = 17 deg., longitude l = 210 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3484669 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 22961 | 2026-08-21 09:56:59 | MASTER-OAFA | (07h 45m 46.70s , +10d 07m 14.0s) | C | 60 | 15.9 | 23036 | 2026-08-21 09:58:15 | MASTER-OAFA | (07h 45m 48.09s , +10d 08m 19.8s) | C | 60 | 16.0 | 23115 | 2026-08-21 09:59:34 | MASTER-OAFA | (07h 45m 53.62s , +10d 07m 28.0s) | C | 60 | 15.9 | 23189 | 2026-08-21 10:00:48 | MASTER-OAFA | (07h 45m 47.68s , +10d 06m 34.3s) | C | 60 | 16.1 | 23266 | 2026-08-21 10:02:05 | MASTER-OAFA | (07h 45m 54.73s , +10d 06m 52.0s) | C | 60 | 16.1 | 23419 | 2026-08-21 10:04:37 | MASTER-OAFA | (07h 45m 51.54s , +10d 07m 21.1s) | C | 60 | 16.3 | 23496 | 2026-08-21 10:05:54 | MASTER-OAFA | (07h 45m 55.51s , +10d 08m 42.3s) | 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/45415. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43635] The EP-WXT trigger 01709286204 is likely a flaring star
by GCN Circulars 21 Aug '26

21 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45414 SUBJECT: The EP-WXT trigger 01709286204 is likely a flaring star DATE: 26/08/21 10:00:40 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> T. Y. Liu (NAO, CAS), D. F. Hu (PMO, CAS)，Z. M. Wang (BNU), Q. Y. Wu, Z. X. Ling (NAO, CAS). on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709286204 at the time of 2026-08-21T09:06:36, is likely a stellar flare associated with CD-55 8799. The estimated flux of the flare is around 1.0 x 10^-10 erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 4.8 x 10^32 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/45414. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43634] GRB 260820A: Insight-HXMT/HE detection
by GCN Circulars 21 Aug '26

21 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45413 SUBJECT: GRB 260820A: Insight-HXMT/HE detection DATE: 26/08/21 09:35:34 GMT FROM: yzh807926(a)163.com Zheng-Hang Yu, Chao Zheng, and Shao-Lin Xiong (IHEP) report on behalf of the Insight-HXMT team: At 2026-08-20T04:24:39.950 (T0), Insight-HXMT/HE detected GRB 260820A, which is also detected by Fermi/GBM (Fermi GBM team, GCN #45409). The Insight-HXMT/HE light curve mainly consists of a pulse with a T90 of 0.22 +0.19/-0.13 s. The 1 s peak rate, measured from T0-0.15 s, is 707 cnts/sec. Insight-HXMT/HE detected a total of 690 counts from this burst. The Insight-HXMT/HE light curve can be found here: https://www.bursthub.cn/gcn/2026/hxmtgrb260820A.png All measurements above are made with the CsI detectors of Insight-HXMT/HE operating in the Normal mode with the energy range of about 60-900 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://hxmten.ihep.ac.cn View this GCN Circular online at https://gcn.nasa.gov/circulars/45413. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43633] IceCube-260821A - IceCube observation of a high-energy neutrino candidate track-like event
by GCN Circulars 21 Aug '26

21 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45412 SUBJECT: IceCube-260821A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 26/08/21 07:23:37 GMT FROM: Cristobal Zilleruelo Cañas at DESY <cristobal.zilleruelo.canas(a)desy.de> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 26-08-21 at 03:34:49.04 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_BRONZE alert stream. Documentation regarding the alert streams and their astrophysical purity can be found here: https://gcn.nasa.gov/missions/icecube. This alert has an estimated false alarm rate of 2.3966 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/143020_51776820.amon) more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 26-08-21 Time: 03:34:49.04 UT RA: 116.67 (+0.49/-0.48 deg 90% PSF containment) J2000 Dec: 10.05 (+0.44/-0.45 deg 90% PSF containment) J2000 As announced in GCN Circular 43419 (https://gcn.nasa.gov/circulars/43419) IceCube alert notices for high-energy track alerts are now also streamed via Kafka. IceCube Gold/Bronze track alerts are available on the Kafka topic 'gcn.notices.icecube.gold_bronze_track_alerts'. The probability distribution of the true neutrino direction, allowing the extraction of precise 90% containment regions around the best-fit direction, is now available for revised reconstruction of high-energy track alerts. The corresponding sky map is distributed as a FITS file and follows the explicit naming convention IceCube-YYMMDDX, where YYMMDD indicates the date of the event and X is a letter distinguishing multiple alerts on the same day. The download link is provided through the GCN schema distributed via Kafka. Detailed documentation describing the alert distribution, schemas, and probability maps is available at: https://gcn.nasa.gov/missions/icecube. No known gamma-ray sources listed in the Fermi LAT 16-year Source List (FL16Y) are located within the 90% uncertainty region of this event. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu View this GCN Circular online at https://gcn.nasa.gov/circulars/45412. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43632] GRB 260818B: SVOM/GRM observation
by GCN Circulars 20 Aug '26

20 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45411 SUBJECT: GRB 260818B: SVOM/GRM observation DATE: 26/08/20 09:16:25 GMT FROM: renyz16607(a)163.com SVOM/GRM team: Yang-Zhao Ren, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Sebastien Guillot (IRAP) Report on behalf of the SVOM team: SVOM/GRM was triggered in-flight by GRB 260818B at 2026-08-18T20:11:12.700 UTC (T0), which is also detected by SVOM/ECLAIRs (Cordier et. al., GCN #45398) and HXMT (Wang et. al., GCN #45408). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of a pulse with a T90 of 0.16 +0.12/-0.04 s in the 15-5000 keV band. The SVOM/GRM light curve can be found here: https://www.bursthub.cn/gcn/2026/svgrb260818B.png In addition, the position of this burst, as determined by SVOM/ECLAIRs (RA= 44.9407, Dec=7.4547, ERR= 4.60 arcmin, GCN #45398), is located at about 29 degrees from the SVOM optical axis. With this localization, the time-averaged spectrum from T0-0.08 to T0+0.12 s is best fitted by a power law function with an exponential high-energy cutoff. The power law index is -1.00 +0.22/-0.23 and the cutoff energy, parameterized as Epeak, is 70 +7/-6 keV. The event fluence (10-1000 keV) in this time interval is (2.67 +0.18/-0.16)E-07 erg/cm^2. The localization of GRB 260818B in the 'Amati' relation diagram is shown at: https://www.bursthub.cn/gcn/2026/svgrb260818B_amati.png The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM point of contact for this burst is: Yang-Zhao Ren (IHEP)(renyz(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/45411. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43631] EP detected a brightening of LMXB 1ES 1735-26.9
by GCN Circulars 20 Aug '26

20 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45410 SUBJECT: EP detected a brightening of LMXB 1ES 1735-26.9 DATE: 26/08/20 08:16:57 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Tian-Yu Liu (NAO, CAS), Xin-Xiang Sun (NAO, CAS), Y.J. Yi (BNU) , Y. Liu (NAO, CAS) on behalf of the Einstein Probe (EP) team: We report on the detection of X-ray brightening of Low Mass X-ray Binary (LMXB) 1ES 1735-26.9 by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The burst triggered EP-WXT (ID: 01709285030) at the time of 2026-08-20 07:27:33 UTC. The WXT position of the source is R.A. = 264.58 deg, DEC = -26.997 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). The estimated flux in the 0.5-4 keV band is around 8.80 x 10^-10 erg/cm^2/s, which is an order of magnitude higher than the previous detection. A follow-up observation with the Follow-up X-ray Telescope (FXT) was performed automatically. An X-ray source was detected at R.A. = 264.5673 deg, DEC = 26.9930 (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic), which is consistent with the position of known LMXB 1ES 1735-26.9. The estimated flux in the 0.5-10 keV band is around 1.95 x 10^-9 erg/cm^2/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/45410. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43630] GRB260820A: Fermi GBM Final Real-Time Localization
by GCN Circulars 20 Aug '26

20 Aug '26

TITLE: GCN CIRCULAR NUMBER: 45409 SUBJECT: GRB260820A: Fermi GBM Final Real-Time Localization DATE: 26/08/20 07:41:32 GMT FROM: Cuán de Barra at UCD <cuan.debarra(a)ucdconnect.ie> The Fermi GBM team reports the detection of a likely SHORT GRB. "At 04:24:39.99 UT on 20 August 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260820A (trigger 808892684/260820184). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 118.3, Dec = -6.1 (J2000 degrees, equivalent to J2000 7h 53m, -6d 5'), with a statistical uncertainty of 11.5 degrees. The angle from the Fermi LAT boresight is 56 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260820184/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260820184/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260820184/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/45409. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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