September 2024 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 35460] EP240918a: GMG Optical Upper Limit
by GCN Circulars 18 Sep '24

18 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37544 SUBJECT: EP240918a: GMG Optical Upper Limit DATE: 24/09/18 15:44:35 GMT FROM: wangbaiting(a)ynao.ac.cn B.-T. Wang, R.-Z. Li, F.-F. Song, J. Mao, Y.-F. Fan and J.-M. Bai (YNAO, CAS) report: We observed the field of EP240918a (Zhang et al., GCN 37541, T0 at 2024-09-18T11:24:37) using the GMG-2.4m telescope at the Lijiang Observatory. The observation began at 2024-09-18T14:02:51, about 2.64 hours after the trigger. No new credible optical counterpart of EP240918a was detected within the EP-FXT error circle (GCN 37541). The preliminary analysis results are shown as follows: +----------------+------------+----------+----------------+ | Tmid-T0 [hr] | Exp. [s] | Filter | 5-sigma U.L. | +================+============+==========+================+ | 2.72 | 600 | R | 20.5 | +----------------+------------+----------+----------------+ The given magnitudes are derived based on calibrating against Pan-STARRS1 field stars. We acknowledge the staff at the Lijiang Observatory for conducting the observation. View this GCN Circular online at https://gcn.nasa.gov/circulars/37544. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35459] EP240918a: GMG Optical Upper Limit
by GCN Circulars 18 Sep '24

18 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37544 SUBJECT: EP240918a: GMG Optical Upper Limit DATE: 24/09/18 15:44:35 GMT FROM: wangbaiting(a)ynao.ac.cn B.-T. Wang, R.-Z. Li, F.-F. Song, J. Mao, Y.-F. Fan and J.-M. Bai (YNAO, CAS) report: We observed the field of EP240918a (Zhang et al., GCN 37541, T0 at 2024-09-18T11:24:37) using the GMG-2.4m telescope at the Lijiang Observatory. The observation began at 2024-09-18T14:02:51, about 2.64 hours after the trigger. No new credible optical counterpart of EP240918a was detected within the EP-FXT error circle (GCN 37541). The preliminary analysis results are shown as follows: +----------------+------------+----------+----------------+ | Tmid-T0 [hr] | Exp. [s] | Filter | 5-sigma U.L. | +================+============+==========+================+ | 2.72 | 600 | R | 20.5 | +----------------+------------+----------+----------------+ The given magnitudes are derived based on calibrating against Pan-STARRS1 field stars. We acknowledge the staff at the Lijiang Observatory for conducting the observation. View this GCN Circular online at https://gcn.nasa.gov/circulars/37544. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35458] GRB 240916A: GRBAlpha detection
by GCN Circulars 18 Sep '24

18 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37543 SUBJECT: GRB 240916A: GRBAlpha detection DATE: 24/09/18 15:01:46 GMT FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz> M. Dafcikova, J. Ripa, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Duriskova, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration. The long-duration GRB 240916A (Fermi/GBM detection: GCN 37518; INTEGRAL/SPI-ACS detection: GCN 37519) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract). The detection was confirmed at the peak time 2024-09-16 01:23:10.8 UTC. The T90 duration measured by GRBAlpha is 27 s and the overall significance during T90 reaches 13 sigma. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240916A_GCN.pdf All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume. View this GCN Circular online at https://gcn.nasa.gov/circulars/37543. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35457] GRB 240914B: GRBAlpha detection
by GCN Circulars 18 Sep '24

18 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37542 SUBJECT: GRB 240914B: GRBAlpha detection DATE: 24/09/18 15:00:44 GMT FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz> M. Dafcikova, J. Ripa, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Duriskova, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration. The long-duration GRB 240914B (AstroSat/CZTI detection: GCN 37506; Fermi/GBM detection: GCN 37524; INTEGRAL/SPI-ACS detection: trigger no. 10905) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract). The detection was confirmed at the peak time 2024-09-14 07:09:51.1 UTC. The T90 duration measured by GRBAlpha is 21.0 s and the overall significance during T90 reaches 18 sigma. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240914B_GCN.pdf All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume. View this GCN Circular online at https://gcn.nasa.gov/circulars/37542. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35456] EP240918a: an X-ray transient detected by Einstein Probe
by GCN Circulars 18 Sep '24

18 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37541 SUBJECT: EP240918a: an X-ray transient detected by Einstein Probe DATE: 24/09/18 13:27:51 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Z. J. Zhang (HKU), Y. F. Liang (PMO, CAS), H. Y. Liu, W. Chen, T. Zhao , Z. X. Ling, J. W. Hu, W. M. Yuan, C. C. Jin, Y. Liu, C. Zhang, H. Q. Cheng, C. Z. Cui, D. W. Fan, H. B. Hu, M. H. Huang, D. Y. Li, M. J. Liu, Z. Z. Lv, T. Y. Lian, X. Mao, H. W. Pan, X. Pan, H. Sun, W. X. Wang, Y. L. Wang, X. P. Xu, Y. F. Xu, H. N. Yang, M. Zhang, W. D. Zhang, W. J. Zhang, Z. Zhang, D. H. Zhao (NAOC, CAS), X. F. Zhao, Y. Chen, S. M. Jia, W. W. Cui, D. W. Han, C. K. Li, L. M. Song, J. Zhang, S. N. Zhang (IHEP, CAS), E. Kuulkers, A. Santovincenzo (ESA), P. O'Brien (Univ. of Leicester), K. Nandra, A. Rau (MPE), B. Cordier (CEA) on behalf of the Einstein Probe team We report on the detection of an X-ray transient designated EP240918a by the Einstein Probe (EP) mission. The transient event triggered the Wide-field X-ray Telescope (WXT) on-board processing unit at 2024-09-18T11:24:37 (UTC). An autonomous observation was performed by the Follow-up X-ray Telescope (FXT) about two minutes later. Afterwards, the FXT on-board processing unit was also triggered, showing that an uncatalogued source was detected at R.A. = 289.3937, DEC = 46.1281 (J2000) with an uncertainty of about 20 arcsec (radius, 90% C.L. statistical and systematic). More information on this source will be updated when the full telemetry data is received. Further follow-up observations are encouraged to identify the nature of this X-ray transient. 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/37541. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35455] GRB 240916A: NOT optical observation
by GCN Circulars 17 Sep '24

17 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37540 SUBJECT: GRB 240916A: NOT optical observation DATE: 24/09/17 23:53:34 GMT FROM: sqjiang at NAOC <sqjiang(a)bao.ac.cn> S.Q. Jiang (NAOC), D. B. Malesani (DAWN/NBI and Radboud Univ.), D. Xu (NAOC), B. N. Hauptmann (NOT) report on behalf of a large collaboration: We observed the optical counterpart (AT 2024vlp / GOTO24fzn: Gompertz et al., GCN 37522; Jiang et al., GCN 37526; Pieterse et al., GCN 37532) of GRB 240916A, detected by Fermi/GBM (Fermi GBM Team, GCNs 37518, 37535) and INTEGRAL SPI/ACS (Pawar et al., GCN 37519) using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera, and obtained 3 x 300 s frames in the Sloan r-band, starting at 20:03:23.239 UT on 2024-09-17, i.e., 42.675 hr after the Fermi/GBM trigger. The afterglow is clearly detected in our stacked image, with a magnitude r = 20.58 +/- 0.04 (AB), calibrated against nearby Pan-STARRS stars and not corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/37540. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35454] GRB 240912A: Swift-BAT refined analysis
by GCN Circulars 17 Sep '24

17 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37539 SUBJECT: GRB 240912A: Swift-BAT refined analysis DATE: 24/09/17 23:48:22 GMT FROM: Mike Moss at NASA GSFC <mikejmoss3(a)gmail.com> T. Parsotan (GSFC), S. D. Barthelmy (GSFC), P. A. Evans (U Leicester), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240912A (trigger #1253910) (P. A. Evans, et al., GCN Circ. 37466). The BAT ground-calculated position is RA, Dec = 124.625, 33.999 deg which is RA(J2000) = 08h 18m 29.9s Dec(J2000) = +33d 59' 56.2" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 86%. The light curve displays an interval of weak flat emission for ~45 seconds before a bright multi-pulsed emission period. There is a possible shallow rise of emission at ~T0+280 seconds coincident with the flare seen in the XRT afterglow. T90 (15-350 keV) is 113.24 +- 7.83 sec (estimated error including systematics). The time-averaged spectrum from T-2.35 to T+373.02 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.43 +- 0.11, and Epeak of 140.5 +- 41.0 keV (chi squared 27.79 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.4 +- 0.0 x 10^-05 erg/cm2 and the 1-sec peak flux measured from T+76.05 sec in the 15-150 keV band is 15.8 +- 0.5 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.68 +- 0.03 (chi squared 43.74 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1253910 View this GCN Circular online at https://gcn.nasa.gov/circulars/37539. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35453] IPN triangulation of GRB 240913С / EP 240913a
by GCN Circulars 17 Sep '24

17 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37538 SUBJECT: IPN triangulation of GRB 240913С / EP 240913a DATE: 24/09/17 20:48:24 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, G. Waratkar, V. Jethwani, J.Joshi, V. Bhalerao, D. Bhattacharya, and S. Vadawale, on behalf of the Astrosat-CZTI team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr, and A.S. Gardner on on behalf of the GRS-Odyssey GRB team, report: The long-duration GRB 240913C (AstroSat-CZTI detection: Dasgupta et al., GCN 37505; ETJASMIN Joint location: Zhang et al., GCN 37507; Fermi-GBM detection: Bissaldi and Meegan, GCN 37509; INTEGRAL-SPI-ACS detection: Pawar et al., GCN 37510) was detected by AstroSat (CZTI), Fermi (GBM trigger 747920561), Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT), and Mars-Odyssey (HEND) at about 42156 s UT (11:42:36). The burst was outside the coded field of view of the BAT. We have triangulated it to the following annuli: --------------------------------------------------- annulus R.A. Dec. R dR (3sigma) (deg) (deg) (deg) (deg) --------------------------------------------------- Konus-GBM 333.897 -8.566 50.692 1.965 Konus-SPI-ACS 334.296 -2.846 47.219 3.486 GBM-SPI-ACS 56.462 86.015 62.390 17.278 GBM-HEND 95.231 23.495 73.181 0.024 --------------------------------------------------- The Konus-GBM, GBM-SPI-ACS and GBM-HEND annuli intersect to form a long box, whose area is 3075 sq. arcmin, and its maximum dimension is 20.8 deg (the minimum one is 3.2 arcmin). The Sun distance was 142 deg. This localization may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM and ETJASMIN joint localizations. The position of the fast X-ray transient EP240913a (Li et al., GCN 37492; Jiang et al., GCN 37497) is inside the IPN localization, strengthening the association of GRB 240913C with the EP240913a initially suggested by Dasgupta et al. (GCN 37505) and Zhang et al. (GCN 37507). A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB240913_T42159/IPN/ The HEALPix triangulation map is the multi-order HEALPix in units of probability density. The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. View this GCN Circular online at https://gcn.nasa.gov/circulars/37538. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35452] GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
by GCN Circulars 17 Sep '24

17 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37537 SUBJECT: GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE DATE: 24/09/17 18:31:44 GMT FROM: Devraj Pawar at R. J. College, Mumbai - 86, India <devrajdp(a)gmail.com> Devraj Pawar (R. J. College, Mumbai-86, India) on behalf of a collaboration studying transients. The Fermi GBM team reported the detection of a burst at 2024-08-25T15:53:00 UTC triggered by Fermi Gamma-ray Burst Monitor (GBM) in GCN 37273. Follow up observations were reported in Gupta et al., GCN 37274; Di Lalla et al., GCN 37288; Evans et al., GCN 37290; Gropp et al., GCN 37294; Kuin et al., GCN 37296; Joshi et al., GCN 37298; Sharma et al., GCN 37301; Frederiks et al., GCN 37302; Chen-Wei et al., GCN 37315; Moss et al., GCN 37355; Leonini et al., GCN 37400; Paek al., GCN 37454; Ruffini et al., GCN 37536. We analyzed the INTEGRAL SPI ACS data around the T0 given in GCN 37273 and detected a peak in the count rate which lasts for about 7 s. The SPI ACS is sensitive above 80 keV; the peak of the burst is at ~35000 counts/s and the steady rate preceding the event is around 3490 counts/s. The peak count rate may be affected by the instruments orientation with respect to the direction of the source. The light curve and the profile is given in the link below : [GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE](https://docs.google.com/document/d/1de6UrFnIK8YoT4n61gwn11wn92oo9Hlv… This work is based on observations with INTEGRAL, an ESA project with instruments and a science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), and with the participation of Russia and the USA. The SPI-ACS detector system has been provided by MPE Garching/Germany. View this GCN Circular online at https://gcn.nasa.gov/circulars/37537. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35451] GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
by GCN Circulars 17 Sep '24

17 Sep '24

TITLE: GCN CIRCULAR NUMBER: 37536 SUBJECT: GRB 240825A: The nature of the afterglow motivates the search of the associated supernova DATE: 24/09/17 16:54:17 GMT FROM: Remo Ruffini at ICRA <ruffini(a)icra.it> R. Ruffini, C.L. Bianco, M. Della Valle, Liang Li, M.T. Mirtorabi, R. Moradi, F. Rastegar Nia, J.A. Rueda, Y. Wang, on behalf of the ICRANet team, report: The T90 of GRB 240825A is only 4 seconds (GCN 37301), and it is located at a relatively close distance (z=0.659, GCN 37293). The fluence reaches a high level of 10^{-4} erg/cm^2. Through spectral analysis, we find that peak energy Ep is about 400 keV and isotropic energy Eiso is about 2x10^{53} erg, consistent with the Amati relation for long-duration gamma-ray bursts. Comparing its X-ray afterglow (see figure attached below, blue dots), its luminosity falls within the range of other long-duration bursts which are associated with supernovae, higher than those of short-duration bursts which have merge origins. Based on these findings, we conclude that GRB 240825A is a long-duration burst (BdHN I; see, e.g., Bianco, et al., 2024, ApJ, 966, 219) and is associated with a SN. The supernova may reach its optical peak in the observer's rest-frame approximately one month after the trigger. Its peak brightness should be within the detection limits of both ground- and space-based telescopes. Therefore, we encourage further observations in the coming weeks. Figure: https://www.icranet.org/documents/GRB_240825A.png View this GCN Circular online at https://gcn.nasa.gov/circulars/37536. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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