April 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 38166] GRB 250412A: AstroSat CZTI detection
by GCN Circulars 14 Apr '25

14 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40142 SUBJECT: GRB 250412A: AstroSat CZTI detection DATE: 25/04/14 06:02:43 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> M. Tembhurnikar (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 250412A which was also detected by Fermi GBM (Trigger Num. 766173972). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2025-04-12 18:06:07.50 UTC. The measured peak count rate associated with the burst is 109 (+29, -26) counts/s above the background in the combined data of three quadrants (out of four), with a total of 411 (+108, -138) counts. The local mean background count rate was 204 (+3, -4) counts/s. Using cumulative rates, we measure a T90 of 6.9 (+2.1, -2.9) s. The source was also faintly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2025-04-12 18:06:08 UTC. The measured peak count rate associated with the burst is 219 (+64, -53) counts/s above the background in the combined data of all quadrants, with a total of 768 (+244, -251) counts. The local mean background count rate was 1231 (+6, -7) counts/s. We cannot reliably estimate the T90 for this GRB in the veto detector data. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project. CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb View this GCN Circular online at https://gcn.nasa.gov/circulars/40142. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38165] EP250404a: Nanshan 0.43m Telescope optical observatios
by GCN Circulars 13 Apr '25

13 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40141 SUBJECT: EP250404a: Nanshan 0.43m Telescope optical observatios DATE: 25/04/13 13:41:02 GMT FROM: Abdusamatjan Iskandar at XAO,CAS <abudu(a)xao.ac.cn> S. Yaqup, J.Z. Liu, A. Iskandar, Y. Zhang, A. Esamdin, C.H. Bai, T.H. Zhong (XAO) report on behalf of optical group of the XAO: We observed the field of the EP250404a (Einstein Probe mission, Trigger ID 01709133918) with the 0.43m telescope at Nanshan Station of Xinjiang Astronomical Observatory (XAO). The observations were started at 2025-04-04T14:54:21(UTC), and obtained a series of gri band images. The optical afterglow (Jiang et al., GCN 40052; Perez-Garcia et al., GCN 40053; Du et al., GCN 40058; Zhu et al., GCN 40061; Konno et al., GCN 40063; Odeh et al, GCN 40064; He et al., GCN 40069; Perez-Fournon et al., GCN 40071; Jelinek et al., GCN 40072; Rakotondrainibe et al, GCN 40073; Taguchi et al., GCN 40074; Ruocco et al., GCN 40076; Martin-Carrillo et al., GCN 40080; Pavoni et al., GCN 40083; Li et al., GCN 40084; Yin et al., GCN 40085; Pankov et al., GCN 40086; Chu Chen et al., GCN 40088 and Chen et al., GCN 40089) was clearly detected at position R.A. = 125.0606 deg, DEC = 35.5282 deg J2000. The preliminary photometric magnitudes are below: Observation Start-Time T-T0(hr) Exposure Filter Mag. Err. 2025-04-04 14:54:21 0.583 060s g 16.914 0.106 2025-04-04 14:55:56 0.604 060s r 16.067 0.076 2025-04-04 14:57:12 0.626 060s i 15.610 0.080 2025-04-04 14:58:29 0.648 060s g 17.090 0.108 2025-04-04 14:59:48 0.669 060s r 16.294 0.072 2025-04-04 15:01:05 0.690 060s i 15.940 0.105 2025-04-04 15:02:22 0.712 060s g 17.484 0.108 2025-04-04 15:03:41 0.734 060s r 16.398 0.071 2025-04-04 15:04:58 0.755 060s i 15.965 0.099 2025-04-04 15:11:08 0.858 120s i 16.388 0.067 2025-04-04 15:13:25 0.897 120s g 17.690 0.106 2025-04-04 15:15:44 0.934 120s r 17.066 0.077 2025-04-04 15:18:01 0.972 120s i 16.496 0.074 2025-04-04 15:20:19 1.011 120s g 17.735 0.096 2025-04-04 15:22:38 1.049 120s r 17.030 0.059 2025-04-04 15:24:54 1.087 120s i 16.736 0.061 2025-04-04 15:27:12 1.126 120s g 18.184 0.105 2025-04-04 15:29:31 1.164 120s r 17.407 0.070 2025-04-04 15:31:48 1.202 120s i 17.033 0.067 2025-04-04 15:34:27 1.247 200s g 18.252 0.090 2025-04-04 15:52:56 1.554 200s r 17.719 0.085 2025-04-04 15:56:33 1.615 200s i 17.332 0.088 2025-04-05 16:00:10 1.676 200s g 18.508 0.116 2025-04-05 16:03:50 1.736 200s r 18.121 0.087 2025-04-05 16:07:27 1.796 200s i 17.742 0.101 2025-04-05 16:11:04 1.857 200s g 18.335 0.093 2025-04-05 16:14:43 1.917 200s r 17.924 0.070 2025-04-05 16:18:19 1.978 200s i 17.569 0.090 2025-04-05 16:25:36 2.099 200s r 18.261 0.081 2025-04-05 16:36:30 2.280 200s r 18.681 0.117 2025-04-05 16:40:06 2.341 200s i 18.319 0.136 2025-04-05 16:43:45 2.402 200s g 18.815 0.129 2025-04-05 16:47:42 2.467 300s g 18.713 0.123 2025-04-05 16:52:59 2.555 300s r 18.799 0.132 2025-04-05 16:58:16 2.643 300s i 17.798 0.094 2025-04-05 17:03:34 2.732 300s g 19.368 0.188 2025-04-05 17:08:52 2.820 300s r 18.608 0.111 The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the magnitudes are not corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/40141. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38164] Fermi trigger No 766148493: Global MASTER-Net observations report
by GCN Circulars 13 Apr '25

13 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40140 SUBJECT: Fermi trigger No 766148493: Global MASTER-Net observations report DATE: 25/04/13 12:17:28 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, 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. 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 (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB250412.46 (trigger No 766148493,18h 37m 40.08s , -21d 24m 00.0s, R=27.37) errorbox 71363 sec after notice time and 71412 sec after trigger time at 2025-04-13 06:51:41 UT, with upper limit up to 19.0 mag. The observations began at zenith distance = 22 deg. The sun altitude is -51.4 deg. The galactic latitude b = -7 deg., longitude l = 13 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2840647 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 71442 | 2025-04-13 06:51:41 | MASTER-OAFA | (16h 41m 59.81s , -14d 00m 54.0s) | C | 60 | 18.9 | 72078 | 2025-04-13 07:02:17 | MASTER-OAFA | (16h 42m 00.36s , -14d 00m 60.0s) | C | 60 | 18.9 | 72712 | 2025-04-13 07:12:51 | MASTER-OAFA | (16h 41m 58.68s , -14d 01m 07.6s) | C | 60 | 18.9 | 73344 | 2025-04-13 07:23:22 | MASTER-OAFA | (16h 41m 58.45s , -14d 01m 17.4s) | C | 60 | 19.0 | 73975 | 2025-04-13 07:33:53 | MASTER-OAFA | (16h 41m 56.43s , -14d 01m 29.7s) | C | 60 | 18.9 | 74436 | 2025-04-13 07:41:44 | MASTER-OAFA | (16h 35m 30.51s , -18d 13m 33.1s) | C | 40 | 17.4 | 74446 | 2025-04-13 07:41:45 | MASTER-OAFA | (16h 45m 08.33s , -17d 49m 39.7s) | C | 60 | 18.9 | 74611 | 2025-04-13 07:44:29 | MASTER-OAFA | (16h 41m 55.83s , -14d 01m 43.6s) | C | 60 | 18.8 | 75080 | 2025-04-13 07:52:28 | MASTER-OAFA | (16h 35m 29.88s , -18d 13m 38.3s) | C | 40 | 17.4 | 75090 | 2025-04-13 07:52:29 | MASTER-OAFA | (16h 45m 07.85s , -17d 49m 44.2s) | C | 60 | 18.8 | 75721 | 2025-04-13 08:03:09 | MASTER-OAFA | (16h 35m 29.19s , -18d 13m 50.2s) | C | 40 | 17.4 | 75731 | 2025-04-13 08:03:09 | MASTER-OAFA | (16h 45m 07.28s , -17d 49m 54.5s) | C | 60 | 18.9 | 76113 | 2025-04-13 08:09:42 | MASTER-OAFA | (16h 40m 23.31s , -12d 33m 39.8s) | C | 40 | 17.3 | 76124 | 2025-04-13 08:09:42 | MASTER-OAFA | (16h 49m 45.59s , -12d 09m 55.2s) | C | 60 | 19.0 | 76352 | 2025-04-13 08:13:41 | MASTER-OAFA | (16h 35m 28.58s , -18d 14m 22.3s) | C | 40 | 17.5 | 76363 | 2025-04-13 08:13:41 | MASTER-OAFA | (16h 45m 06.73s , -17d 50m 26.1s) | C | 60 | 18.9 | 76741 | 2025-04-13 08:20:09 | MASTER-OAFA | (16h 40m 23.12s , -12d 34m 01.7s) | C | 40 | 17.4 | 76751 | 2025-04-13 08:20:09 | MASTER-OAFA | (16h 49m 45.46s , -12d 10m 17.1s) | C | 60 | 19.0 | 76977 | 2025-04-13 08:24:05 | MASTER-OAFA | (16h 35m 28.03s , -18d 14m 44.0s) | C | 40 | 17.4 | 76987 | 2025-04-13 08:24:06 | MASTER-OAFA | (16h 45m 06.25s , -17d 50m 47.6s) | C | 60 | 18.9 | 77365 | 2025-04-13 08:30:34 | MASTER-OAFA | (16h 40m 21.49s , -12d 34m 25.5s) | C | 40 | 17.4 | 77376 | 2025-04-13 08:30:34 | MASTER-OAFA | (16h 49m 43.82s , -12d 10m 40.7s) | C | 60 | 19.0 | 77605 | 2025-04-13 08:34:33 | MASTER-OAFA | (16h 35m 27.53s , -18d 14m 38.7s) | C | 40 | 17.5 | 77615 | 2025-04-13 08:34:33 | MASTER-OAFA | (16h 45m 05.72s , -17d 50m 42.0s) | C | 60 | 18.9 | 78005 | 2025-04-13 08:41:13 | MASTER-OAFA | (16h 40m 20.17s , -12d 34m 52.6s) | C | 40 | 17.3 | 78015 | 2025-04-13 08:41:14 | MASTER-OAFA | (16h 49m 42.55s , -12d 11m 07.5s) | C | 60 | 19.0 | 78081 | 2025-04-13 08:42:30 | MASTER-OAFA | (16h 41m 20.13s , -16d 21m 21.6s) | C | 40 | 17.3 | 78092 | 2025-04-13 08:42:30 | MASTER-OAFA | (16h 50m 52.28s , -15d 57m 29.2s) | C | 60 | 18.8 | 78170 | 2025-04-13 08:43:49 | MASTER-OAFA | (16h 40m 20.39s , -19d 42m 46.1s) | C | 60 | 18.8 | 78633 | 2025-04-13 08:51:41 | MASTER-OAFA | (16h 40m 18.89s , -12d 35m 21.0s) | C | 40 | 17.3 | 78643 | 2025-04-13 08:51:42 | MASTER-OAFA | (16h 49m 41.25s , -12d 11m 35.4s) | C | 60 | 19.0 | 78713 | 2025-04-13 08:53:01 | MASTER-OAFA | (16h 41m 21.18s , -16d 21m 52.5s) | C | 40 | 17.3 | 78723 | 2025-04-13 08:53:01 | MASTER-OAFA | (16h 50m 53.34s , -15d 57m 59.8s) | C | 60 | 18.8 | 78801 | 2025-04-13 08:54:19 | MASTER-OAFA | (16h 40m 20.18s , -19d 43m 30.6s) | C | 60 | 18.8 | 79314 | 2025-04-13 09:03:02 | MASTER-OAFA | (16h 40m 18.08s , -12d 35m 54.6s) | C | 40 | 17.3 | 79324 | 2025-04-13 09:03:02 | MASTER-OAFA | (16h 49m 40.44s , -12d 12m 09.5s) | C | 60 | 19.0 | 79390 | 2025-04-13 09:04:19 | MASTER-OAFA | (16h 41m 18.83s , -16d 22m 11.9s) | C | 40 | 17.3 | 79401 | 2025-04-13 09:04:19 | MASTER-OAFA | (16h 50m 50.92s , -15d 58m 18.8s) | C | 60 | 18.8 | 79479 | 2025-04-13 09:05:37 | MASTER-OAFA | (16h 40m 20.15s , -19d 43m 53.1s) | C | 60 | 18.8 | 79797 | 2025-04-13 09:10:55 | MASTER-OAFA | (16h 36m 33.34s , -21d 36m 50.4s) | C | 60 | 18.8 | 80061 | 2025-04-13 09:15:29 | MASTER-OAFA | (16h 41m 18.16s , -16d 22m 52.3s) | C | 40 | 17.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/40140. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38163] Fermi trigger No 766173972: Global MASTER-Net observations report
by GCN Circulars 12 Apr '25

12 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40139 SUBJECT: Fermi trigger No 766173972: Global MASTER-Net observations report DATE: 25/04/12 20:01:03 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, 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. 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB250412.75 (trigger No 766173972,23h 19m 21.60s , -81d 40m 12.0s, R=4.38) errorbox 29 sec after notice time and 92 sec after trigger time at 2025-04-12 18:07:39 UT, with upper limit up to 17.9 mag. The observations began at zenith distance = 62 deg. The sun altitude is -23.4 deg. The galactic latitude b = -35 deg., longitude l = 307 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2840903 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 103 | 2025-04-12 18:07:39 | MASTER-SAAO | (00h 46m 29.97s , -81d 52m 11.8s) | C | 20 | 16.4 | 128 | 2025-04-12 18:07:39 | MASTER-SAAO | (00h 46m 29.96s , -81d 52m 11.8s) | C | 70 | 17.5 | Coadd 142 | 2025-04-12 18:08:18 | MASTER-SAAO | (00h 46m 30.73s , -81d 52m 12.6s) | C | 20 | 16.8 | 186 | 2025-04-12 18:08:57 | MASTER-SAAO | (00h 46m 31.35s , -81d 52m 13.6s) | C | 30 | 17.1 | 240 | 2025-04-12 18:09:47 | MASTER-SAAO | (00h 46m 32.24s , -81d 52m 14.8s) | C | 40 | 17.1 | 295 | 2025-04-12 18:09:47 | MASTER-SAAO | (00h 46m 32.21s , -81d 52m 14.8s) | C | 150 | 17.9 | Coadd 304 | 2025-04-12 18:10:46 | MASTER-SAAO | (00h 46m 33.63s , -81d 52m 16.4s) | C | 50 | 17.3 | 378 | 2025-04-12 18:11:55 | MASTER-SAAO | (00h 46m 34.57s , -81d 52m 17.7s) | C | 60 | 17.3 | 468 | 2025-04-12 18:13:24 | MASTER-SAAO | (23h 16m 39.62s , -82d 17m 26.5s) | C | 60 | 16.8 | 635 | 2025-04-12 18:16:12 | MASTER-SAAO | (23h 07m 15.27s , -81d 33m 20.6s) | C | 60 | 16.4 | 695 | 2025-04-12 18:16:12 | MASTER-SAAO | (23h 07m 15.34s , -81d 33m 20.6s) | C | 180 | 17.6 | Coadd 714 | 2025-04-12 18:17:30 | MASTER-SAAO | (23h 07m 15.41s , -81d 33m 15.7s) | C | 60 | 17.1 | 793 | 2025-04-12 18:18:49 | MASTER-SAAO | (23h 07m 15.65s , -81d 33m 12.1s) | C | 60 | 17.0 | 872 | 2025-04-12 18:20:08 | MASTER-SAAO | (23h 07m 16.05s , -81d 33m 09.8s) | C | 60 | 17.0 | 1125 | 2025-04-12 18:24:22 | MASTER-SAAO | (00h 39m 40.29s , -82d 33m 58.2s) | C | 60 | 16.6 | 1449 | 2025-04-12 18:29:45 | MASTER-SAAO | (23h 16m 54.42s , -82d 19m 17.7s) | C | 60 | 16.7 | 1528 | 2025-04-12 18:31:05 | MASTER-SAAO | (22h 15m 53.97s , -82d 17m 25.3s) | C | 60 | 16.5 | 1608 | 2025-04-12 18:32:24 | MASTER-SAAO | (23h 16m 36.44s , -82d 18m 37.3s) | C | 60 | 16.8 | 1687 | 2025-04-12 18:33:44 | MASTER-SAAO | (22h 26m 17.48s , -80d 24m 17.0s) | C | 60 | 16.4 | 1766 | 2025-04-12 18:35:03 | MASTER-SAAO | (23h 14m 57.88s , -80d 23m 02.5s) | C | 60 | 16.5 | 1855 | 2025-04-12 18:36:32 | MASTER-SAAO | (00h 39m 46.51s , -82d 35m 00.3s) | C | 60 | 16.8 | 1945 | 2025-04-12 18:38:01 | MASTER-SAAO | (23h 25m 13.11s , -80d 24m 59.7s) | C | 60 | 16.8 | 2035 | 2025-04-12 18:39:31 | MASTER-SAAO | (00h 31m 31.32s , -80d 40m 19.1s) | C | 60 | 17.1 | 2124 | 2025-04-12 18:41:01 | MASTER-SAAO | (23h 17m 06.68s , -82d 19m 06.9s) | C | 60 | 17.1 | 2203 | 2025-04-12 18:42:20 | MASTER-SAAO | (22h 16m 04.94s , -82d 17m 40.7s) | C | 60 | 17.0 | 2283 | 2025-04-12 18:43:39 | MASTER-SAAO | (23h 16m 43.16s , -82d 18m 06.1s) | C | 60 | 17.4 | 2362 | 2025-04-12 18:44:58 | MASTER-SAAO | (22h 26m 24.24s , -80d 23m 23.1s) | C | 60 | 17.3 | 2441 | 2025-04-12 18:46:18 | MASTER-SAAO | (23h 15m 09.95s , -80d 24m 06.0s) | C | 60 | 17.1 | 2530 | 2025-04-12 18:47:47 | MASTER-SAAO | (00h 39m 50.25s , -82d 36m 27.6s) | C | 60 | 17.2 | 2850 | 2025-04-12 18:53:07 | MASTER-SAAO | (23h 25m 21.81s , -80d 25m 00.7s) | C | 60 | 17.1 | 2939 | 2025-04-12 18:54:36 | MASTER-SAAO | (00h 31m 41.67s , -80d 40m 47.8s) | C | 60 | 17.4 | 3028 | 2025-04-12 18:56:05 | MASTER-SAAO | (23h 17m 19.69s , -82d 19m 05.1s) | C | 60 | 17.4 | 3108 | 2025-04-12 18:57:24 | MASTER-SAAO | (22h 16m 15.77s , -82d 18m 00.3s) | C | 60 | 17.6 | 3187 | 2025-04-12 18:58:44 | MASTER-SAAO | (23h 16m 56.52s , -82d 18m 19.9s) | C | 60 | 17.5 | 3267 | 2025-04-12 19:00:03 | MASTER-SAAO | (22h 26m 34.41s , -80d 23m 41.5s) | C | 60 | 17.5 | 3353 | 2025-04-12 19:01:30 | MASTER-SAAO | (23h 15m 20.80s , -80d 24m 20.0s) | C | 60 | 17.4 | 3442 | 2025-04-12 19:02:58 | MASTER-SAAO | (00h 40m 00.06s , -82d 37m 02.6s) | C | 60 | 17.4 | 3533 | 2025-04-12 19:04:30 | MASTER-SAAO | (23h 25m 31.97s , -80d 24m 57.3s) | C | 60 | 17.3 | 3618 | 2025-04-12 19:05:55 | MASTER-SAAO | (00h 14m 03.61s , -80d 22m 51.5s) | C | 60 | 17.4 | 3698 | 2025-04-12 19:07:14 | MASTER-SAAO | (23h 17m 21.18s , -82d 19m 04.4s) | C | 60 | 17.6 | 3777 | 2025-04-12 19:08:33 | MASTER-SAAO | (22h 16m 17.15s , -82d 17m 59.7s) | C | 60 | 17.6 | 3856 | 2025-04-12 19:09:53 | MASTER-SAAO | (23h 17m 00.72s , -82d 18m 23.9s) | C | 60 | 17.5 | 3936 | 2025-04-12 19:11:12 | MASTER-SAAO | (22h 26m 36.06s , -80d 23m 49.6s) | C | 60 | 17.5 | 4015 | 2025-04-12 19:12:32 | MASTER-SAAO | (23h 15m 23.71s , -80d 24m 25.9s) | C | 60 | 17.3 | 4095 | 2025-04-12 19:13:51 | MASTER-SAAO | (00h 18m 08.69s , -82d 18m 44.5s) | C | 60 | 17.6 | 4174 | 2025-04-12 19:15:10 | MASTER-SAAO | (23h 25m 30.83s , -80d 25m 00.8s) | C | 60 | 17.3 | 4253 | 2025-04-12 19:16:30 | MASTER-SAAO | (00h 14m 09.22s , -80d 22m 57.9s) | C | 60 | 17.4 | 4333 | 2025-04-12 19:17:49 | MASTER-SAAO | (23h 17m 28.05s , -82d 19m 02.7s) | C | 60 | 17.5 | 4415 | 2025-04-12 19:19:11 | MASTER-SAAO | (22h 16m 21.76s , -82d 18m 25.1s) | C | 60 | 17.6 | 4494 | 2025-04-12 19:20:31 | MASTER-SAAO | (23h 17m 07.52s , -82d 18m 31.0s) | C | 60 | 17.6 | 4573 | 2025-04-12 19:21:50 | MASTER-SAAO | (22h 26m 39.76s , -80d 24m 00.5s) | C | 60 | 17.5 | 4653 | 2025-04-12 19:23:09 | MASTER-SAAO | (23h 15m 28.97s , -80d 24m 35.3s) | C | 60 | 17.3 | 4732 | 2025-04-12 19:24:29 | MASTER-SAAO | (00h 18m 16.70s , -82d 18m 49.5s) | C | 60 | 17.4 | 4812 | 2025-04-12 19:25:48 | MASTER-SAAO | (23h 25m 37.20s , -80d 25m 14.8s) | C | 60 | 17.4 | 4891 | 2025-04-12 19:27:08 | MASTER-SAAO | (00h 14m 16.02s , -80d 23m 09.7s) | C | 60 | 17.4 | 4971 | 2025-04-12 19:28:27 | MASTER-SAAO | (22h 01m 08.20s , -84d 12m 36.1s) | C | 60 | 17.6 | 5050 | 2025-04-12 19:29:47 | MASTER-SAAO | (23h 22m 16.17s , -84d 12m 32.8s) | C | 60 | 17.6 | 5130 | 2025-04-12 19:31:06 | MASTER-SAAO | (22h 16m 24.57s , -82d 18m 15.7s) | C | 60 | 17.5 | 5209 | 2025-04-12 19:32:26 | MASTER-SAAO | (23h 17m 23.60s , -82d 18m 43.4s) | C | 60 | 17.5 | 5288 | 2025-04-12 19:33:45 | MASTER-SAAO | (22h 26m 43.56s , -80d 26m 17.1s) | C | 60 | 17.6 | 5368 | 2025-04-12 19:35:04 | MASTER-SAAO | (23h 15m 36.28s , -80d 25m 41.7s) | C | 60 | 17.4 | 5447 | 2025-04-12 19:36:23 | MASTER-SAAO | (23h 25m 44.09s , -80d 23m 58.2s) | C | 60 | 17.5 | 5527 | 2025-04-12 19:37:43 | MASTER-SAAO | (00h 14m 22.67s , -80d 24m 57.2s) | C | 60 | 17.5 | 5606 | 2025-04-12 19:39:02 | MASTER-SAAO | (22h 01m 17.48s , -84d 12m 35.9s) | C | 60 | 17.5 | 5685 | 2025-04-12 19:40:22 | MASTER-SAAO | (23h 22m 28.74s , -84d 12m 43.8s) | C | 60 | 17.6 | 5765 | 2025-04-12 19:41:41 | MASTER-SAAO | (23h 04m 31.91s , -84d 12m 56.7s) | C | 60 | 17.5 | 5844 | 2025-04-12 19:43:01 | MASTER-SAAO | (00h 25m 27.62s , -84d 12m 53.1s) | C | 60 | 17.6 | 5927 | 2025-04-12 19:44:23 | MASTER-SAAO | (22h 35m 02.04s , -78d 30m 48.3s) | C | 60 | 17.5 | 6006 | 2025-04-12 19:45:43 | MASTER-SAAO | (23h 15m 42.29s , -78d 31m 29.4s) | C | 60 | 17.1 | 6085 | 2025-04-12 19:47:02 | MASTER-SAAO | (23h 31m 02.44s , -78d 30m 47.0s) | C | 60 | 17.4 | 6165 | 2025-04-12 19:48:21 | MASTER-SAAO | (00h 11m 40.44s , -78d 29m 09.4s) | C | 60 | 17.4 | 6244 | 2025-04-12 19:49:41 | MASTER-SAAO | (22h 01m 22.34s , -84d 13m 42.0s) | C | 60 | 17.5 | 6324 | 2025-04-12 19:51:00 | MASTER-SAAO | (23h 22m 37.77s , -84d 13m 55.3s) | C | 60 | 17.5 | 6403 | 2025-04-12 19:52:19 | MASTER-SAAO | (23h 04m 40.45s , -84d 13m 39.8s) | C | 60 | 17.4 | 6482 | 2025-04-12 19:53:39 | MASTER-SAAO | (00h 25m 47.79s , -84d 11m 23.9s) | C | 60 | 17.5 | 6561 | 2025-04-12 19:54:58 | MASTER-SAAO | (22h 35m 05.70s , -78d 32m 14.7s) | C | 60 | 17.5 | 6640 | 2025-04-12 19:56:17 | MASTER-SAAO | (23h 15m 51.84s , -78d 30m 39.4s) | C | 60 | 16.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/40139. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38162] GRB 250411A: DDOTI Optical Observations
by GCN Circulars 12 Apr '25

12 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40138 SUBJECT: GRB 250411A: DDOTI Optical Observations DATE: 25/04/12 15:05:03 GMT FROM: sahil.atri(a)students.uniroma2.eu Sahil Atri (U Roma), Rosa L. Becerra (U Roma), Alan M. Watson (UNAM), Eleonora Troja (U Roma), Camila Angulo Valdez (UNAM), Nat Butler (ASU), Simone Dichiara (Penn State University), Tsvetelina Dimitrova (ASU), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl López (UNAM) and Margarita Pereyra (UNAM) report: We observed the field of the GRB 250411A detected by Fermi/GBM (Fermi GBM Team, GCN 40136) with the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir (http://ddoti.astroscu.unam.mx) on the night of 2025-04-12 UTC from 07:13 UTC to 12:05 UTC (from T+12.9 h to T+17.8 h after the trigger) and obtained a total exposure of 1.94 hours. Comparing our observations to the USNO-B1 and Pan-STARRS PS1 DR2 catalogues, we detect no evident uncatalogued sources within the observed field to a 10-sigma limiting AB magnitude of: w > 18.93-19.65 This value is not corrected for the Galactic extinction. We thank the staff of the Observatorio Astronómico Nacional on the Sierra of San Pedro Mártir. View this GCN Circular online at https://gcn.nasa.gov/circulars/40138. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38161] Fermi GRB 250411A: Global MASTER-Net observations report
by GCN Circulars 11 Apr '25

11 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40137 SUBJECT: Fermi GRB 250411A: Global MASTER-Net observations report DATE: 25/04/11 20:31:21 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, 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. 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 250411A ( Fermi GBM team, GCN 40136) errorbox 7115 sec after notice time and 7149 sec after trigger time at 2025-04-11 20:16:18 UT, with upper limit up to 17.6 mag. The observations began at zenith distance = 75 deg. The sun altitude is -49.3 deg. The galactic latitude b = 24 deg., longitude l = 1 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2840071 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 7179 | 2025-04-11 20:16:18 | MASTER-SAAO | (16h 18m 59.95s , -13d 56m 46.1s) | C | 60 | 17.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/40137. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38160] GRB 250411A: Fermi GBM Final Real-time Localization
by GCN Circulars 11 Apr '25

11 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40136 SUBJECT: GRB 250411A: Fermi GBM Final Real-time Localization DATE: 25/04/11 18:27:41 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 18:17:09 UT on 11 Apr 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250411A (trigger 766088234.189348 / 250411762). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 245.7, Dec = -13.9 (J2000 degrees, equivalent to J2000 16h 22m, -13d 54'), with a statistical uncertainty of 3.4 degrees. The angle from the Fermi LAT boresight is 98.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250411762/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250411762/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250411762/… View this GCN Circular online at https://gcn.nasa.gov/circulars/40136. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38159] GRB 250407A: Continued KAIT/Nickel optical observations
by GCN Circulars 11 Apr '25

11 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40135 SUBJECT: GRB 250407A: Continued KAIT/Nickel optical observations DATE: 25/04/11 07:26:26 GMT FROM: Weikang Zheng at UC Berkeley <weikang(a)berkeley.edu> Asia deGraw, Gracelynn Jost, WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, continued the observation of GRB 250407A optical afterglow (Zheng et al., GCN 40116; Ducoin et. al, GCN 40117; Pérez-Fournon et. al, GCN 40125; Pankov et al., GCN 40133) at 03:35 UT, Apr. 09, namely ~1.55 days after burst. A set of clear (roughly R) filter images were obtained. Compared to our earlier observations (Zheng et al., GCN 40116), the reported afterglow had faded to ~20.8 +/- 0.3 mag (Vega) measured in our coadd image. Additional R band images with 600sx5 exposure were obtained with the 1-m Nickel telescopes located at Lick observatory, starting at ~1.55 days after burst. We measure the brightness of R ~ 21.0 +/- 0.2 mag (Vega), similar to the R band magnitude reported by Pankov et al. (GCN 40133) at a slightly later epoch (1.98 days), suggesting that this might be the host galaxy of GRB 250407A as suggested by Ducoin et. al, GCN 40117). View this GCN Circular online at https://gcn.nasa.gov/circulars/40135. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38158] GRB 250314A: e-MERLIN observations
by GCN Circulars 10 Apr '25

10 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40134 SUBJECT: GRB 250314A: e-MERLIN observations DATE: 25/04/10 20:17:58 GMT FROM: Aishwarya L Thakur at INAF-IAPS, Rome <aishth(a)outlook.com> A.L. Thakur [1], G. Bruni [1], L. Piro [1] and G. Gianfagna [1] report: We observed the z=7.3 GRB 250314A (SVOM GCN 39719, VLT/X-shooter GCN 39732, GTC/OSIRIS+ GCN 39743), with the e-MERLIN radio telescope under project RR19004 (PI: Thakur) at 5 GHz starting from Mar 31 (~17 days post-GRB) for three runs of ~12 hours each. 1331+3030 was used for flux scale calibration, and 1332-0509 for complex gain. The beam size was 122x34 milli-arcsec. Data were reduced with the e-MERLIN pipeline and imaged with CASA. The image RMS was 18 uJy/beam. We do not find statistically significant emission at a level above 5-sigma at the position of the NOT counterpart (GCN 39727) or in the broader 2x2 arcsec field. We thus set a 5-sigma upper limit of 90 uJy at 5 GHz. Further e-MERLIN observations are planned. We thank the e-MERLIN director for promptly approving these DDT observations and acknowledge Justin Bray's excellent support in scheduling and executing them. e-MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC, part of UK Research and Innovation. —------------------------ [1] INAF-IAPS View this GCN Circular online at https://gcn.nasa.gov/circulars/40134. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38157] GRB 250407A: Mondy and AbAO Optical Observations
by GCN Circulars 10 Apr '25

10 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40133 SUBJECT: GRB 250407A: Mondy and AbAO Optical Observations DATE: 25/04/10 09:17:26 GMT FROM: Nicolai Pankov at HSE, IKI RAS <colinsergesen(a)gmail.com> N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), R. Ya. Inasaridze (AbAO) report on behalf of IKI-GRB-FuN: We observed the field of GRB 250407A detected by Fermi (the Fermi GBM team, GCN 40104; Preis & Greiner, GCN 40105; Mukherjee & Meegan, GCN 40114), SRG (Molkov et. al, GCN 40110), Swift (Evans, GCN 40111; Dichiara et. al, GCN 40113), EP (Zheng et. al, GCN 40119), Konus-Wind (Frederiks et. al, GCN 40121) with the 1.5-meter AZT-33IK telescope of the Sayan Solar Observatory (Mondy), and the 0.7-meter AS-32 telescope of the Abastumani Astrophysical Observatory (AbAO). The R-band observations began on 2025-04-08 at 18:01:15 UT, i.e. ~1.12 days since trigger at AbAO. The optical counterpart (Zheng & Fillipenko, GCN 40116; Ducoin et. al, GCN 40117; Pérez-Fournon et. al, GCN 40125) is marginally detected in the stacked image taken with AZT-33IK. The preliminary photometry is as follows: Date UTstart Exptime t-T0 Filter OT Err UL Telescope (s) (mid, days) (3sigma) 2025-04-08 18:01:15 89*60 1.12319 R n/d n/d 17.5 AS-32 2025-04-09 14:42:55 34*120 1.97818 R 21.0 0.3 21.2 AZT-33IK Ref. stars USNO-B1.0 RA Dec R2mag 110.81407 36.79950 15.86 110.78017 36.81867 14.55 The photometry is based on nearby USNO-B1.0 stars (R2 magnitudes) and has not been corrected for the Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/40133. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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