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

[vsnet-grb-info 37077] The EP-WXT trigger 01709131085 is likely a flaring star
by GCN Circulars 29 Jan '25

29 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39068 SUBJECT: The EP-WXT trigger 01709131085 is likely a flaring star DATE: 25/01/29 05:37:57 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> D. Y. Li (NAOC, CAS), Y.-H. I. Yin (NJU), W. M. Yuan (NAOC, CAS) report on behalf of the Einstein Probe team: The EP-WXT trigger (ID: 01709131085) on 2025-01-29 04:49:22 (UTC) is likely a stellar flare associated with a high proper motion star RX J0448.7+1003. The estimated flux of the flare is around 2.0 x 10^-10 erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 7.1 x 10^30 erg/s. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with onboard 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/39068. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37076] Fermi GRB 250128B: Global MASTER-Net observations report
by GCN Circulars 29 Jan '25

29 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39067 SUBJECT: Fermi GRB 250128B: Global MASTER-Net observations report DATE: 25/01/29 05:30:51 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 250128B ( Fermi GBM team, GCN 39057) errorbox 26118 sec after notice time and 26157 sec after trigger time at 2025-01-28 23:38:50 UT, with upper limit up to 18.7 mag. The observations began at zenith distance = 76 deg. The sun altitude is -38.7 deg. The galactic latitude b = -9 deg., longitude l = 344 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2759250 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 26187 | 2025-01-28 23:38:50 | MASTER-SAAO | (16h 54m 01.94s , -51d 54m 03.8s) | C | 60 | 14.5 | 26645 | 2025-01-28 23:46:28 | MASTER-SAAO | (17h 07m 34.90s , -48d 08m 01.7s) | C | 60 | 13.5 | 30371 | 2025-01-29 00:48:34 | MASTER-SAAO | (16h 55m 30.58s , -48d 08m 09.4s) | C | 60 | 12.1 | 30450 | 2025-01-29 00:49:53 | MASTER-SAAO | (17h 07m 31.89s , -48d 07m 22.2s) | C | 60 | 12.6 | 30529 | 2025-01-29 00:51:13 | MASTER-SAAO | (17h 25m 40.30s , -46d 15m 46.5s) | C | 60 | 15.9 | 30609 | 2025-01-29 00:52:32 | MASTER-SAAO | (17h 37m 21.80s , -46d 15m 49.3s) | C | 60 | 15.1 | 31804 | 2025-01-29 01:12:28 | MASTER-SAAO | (16h 53m 49.95s , -51d 55m 37.6s) | C | 60 | 15.4 | 31884 | 2025-01-29 01:13:47 | MASTER-SAAO | (16h 55m 31.05s , -48d 09m 30.8s) | C | 60 | 17.2 | 31963 | 2025-01-29 01:15:06 | MASTER-SAAO | (17h 07m 34.80s , -48d 08m 03.8s) | C | 60 | 17.0 | 32243 | 2025-01-29 01:19:46 | MASTER-SAAO | (17h 25m 37.93s , -46d 14m 13.1s) | C | 60 | 14.9 | 32322 | 2025-01-29 01:21:05 | MASTER-SAAO | (17h 37m 19.22s , -46d 15m 27.6s) | C | 60 | 14.3 | 32481 | 2025-01-29 01:23:44 | MASTER-SAAO | (16h 53m 52.00s , -51d 57m 29.7s) | C | 60 | 16.1 | 32560 | 2025-01-29 01:25:03 | MASTER-SAAO | (16h 55m 30.06s , -48d 08m 10.8s) | C | 60 | 17.9 | 32639 | 2025-01-29 01:26:22 | MASTER-SAAO | (17h 07m 30.76s , -48d 09m 30.5s) | C | 60 | 17.6 | 32718 | 2025-01-29 01:27:42 | MASTER-SAAO | (17h 18m 16.31s , -48d 09m 14.3s) | C | 60 | 17.3 | 32798 | 2025-01-29 01:29:01 | MASTER-SAAO | (17h 30m 18.33s , -48d 08m 28.5s) | C | 60 | 17.3 | 32877 | 2025-01-29 01:30:21 | MASTER-SAAO | (17h 25m 43.58s , -46d 15m 26.3s) | C | 60 | 17.5 | 32957 | 2025-01-29 01:31:40 | MASTER-SAAO | (17h 37m 12.35s , -46d 16m 40.3s) | C | 60 | 17.0 | 33115 | 2025-01-29 01:34:19 | MASTER-SAAO | (16h 53m 47.39s , -51d 55m 49.0s) | C | 60 | 16.3 | 33195 | 2025-01-29 01:35:38 | MASTER-SAAO | (16h 55m 28.67s , -48d 09m 42.8s) | C | 60 | 17.3 | 33475 | 2025-01-29 01:40:18 | MASTER-SAAO | (17h 07m 26.19s , -48d 09m 10.5s) | C | 60 | 17.6 | 33554 | 2025-01-29 01:41:37 | MASTER-SAAO | (17h 18m 15.01s , -48d 08m 25.7s) | C | 60 | 16.8 | 33633 | 2025-01-29 01:42:57 | MASTER-SAAO | (17h 30m 20.98s , -48d 09m 41.3s) | C | 60 | 16.5 | 33713 | 2025-01-29 01:44:16 | MASTER-SAAO | (17h 25m 36.21s , -46d 16m 39.3s) | C | 60 | 17.3 | 33792 | 2025-01-29 01:45:35 | MASTER-SAAO | (17h 37m 17.42s , -46d 16m 36.8s) | C | 60 | 17.0 | 33872 | 2025-01-29 01:46:55 | MASTER-SAAO | (16h 55m 27.37s , -48d 08m 29.5s) | C | 60 | 16.3 | 33951 | 2025-01-29 01:48:15 | MASTER-SAAO | (17h 33m 38.21s , -44d 21m 23.3s) | C | 60 | 15.5 | 34031 | 2025-01-29 01:49:34 | MASTER-SAAO | (17h 44m 46.86s , -44d 22m 07.8s) | C | 60 | 15.1 | 34110 | 2025-01-29 01:50:53 | MASTER-SAAO | (17h 07m 25.08s , -48d 08m 18.6s) | C | 60 | 17.1 | 34189 | 2025-01-29 01:52:12 | MASTER-SAAO | (17h 18m 19.31s , -48d 09m 34.6s) | C | 60 | 17.0 | 34268 | 2025-01-29 01:53:32 | MASTER-SAAO | (17h 30m 15.48s , -48d 10m 51.3s) | C | 60 | 17.4 | 34348 | 2025-01-29 01:54:51 | MASTER-SAAO | (17h 25m 39.83s , -46d 16m 26.1s) | C | 60 | 17.5 | 34427 | 2025-01-29 01:56:11 | MASTER-SAAO | (17h 37m 12.76s , -46d 15m 22.7s) | C | 60 | 17.1 | 34706 | 2025-01-29 02:00:49 | MASTER-SAAO | (17h 33m 37.71s , -44d 21m 26.5s) | C | 60 | 17.1 | 34787 | 2025-01-29 02:02:10 | MASTER-SAAO | (17h 44m 44.57s , -44d 22m 19.1s) | C | 60 | 17.0 | 34866 | 2025-01-29 02:03:30 | MASTER-SAAO | (17h 18m 13.41s , -48d 08m 42.4s) | C | 60 | 15.6 | 34946 | 2025-01-29 02:04:49 | MASTER-SAAO | (17h 30m 18.40s , -48d 10m 00.7s) | C | 60 | 16.2 | 35025 | 2025-01-29 02:06:08 | MASTER-SAAO | (17h 25m 33.37s , -46d 16m 57.8s) | C | 60 | 17.2 | 35104 | 2025-01-29 02:07:27 | MASTER-SAAO | (17h 37m 14.58s , -46d 16m 48.0s) | C | 60 | 16.9 | 35184 | 2025-01-29 02:08:47 | MASTER-SAAO | (17h 41m 05.26s , -48d 11m 14.0s) | C | 60 | 17.1 | 35263 | 2025-01-29 02:10:06 | MASTER-SAAO | (17h 53m 10.47s , -48d 09m 56.4s) | C | 60 | 17.0 | 35343 | 2025-01-29 02:11:26 | MASTER-SAAO | (17h 33m 31.26s , -44d 22m 13.5s) | C | 60 | 17.2 | 35422 | 2025-01-29 02:12:45 | MASTER-SAAO | (17h 44m 44.37s , -44d 21m 30.1s) | C | 60 | 16.9 | 35501 | 2025-01-29 02:14:04 | MASTER-SAAO | (17h 18m 16.78s , -48d 09m 51.5s) | C | 60 | 16.8 | 35581 | 2025-01-29 02:15:24 | MASTER-SAAO | (17h 30m 12.42s , -48d 11m 09.5s) | C | 60 | 17.3 | 35660 | 2025-01-29 02:16:43 | MASTER-SAAO | (17h 12m 14.68s , -44d 21m 08.1s) | C | 60 | 16.9 | 35938 | 2025-01-29 02:21:21 | MASTER-SAAO | (17h 23m 30.01s , -44d 21m 27.4s) | C | 60 | 16.5 | 36018 | 2025-01-29 02:22:41 | MASTER-SAAO | (17h 41m 00.34s , -48d 10m 28.6s) | C | 60 | 15.7 | 36097 | 2025-01-29 02:24:00 | MASTER-SAAO | (17h 53m 01.26s , -48d 09m 45.3s) | C | 60 | 16.1 | 36176 | 2025-01-29 02:25:19 | MASTER-SAAO | (17h 33m 35.46s , -44d 22m 23.6s) | C | 60 | 16.2 | 36255 | 2025-01-29 02:26:39 | MASTER-SAAO | (17h 44m 41.67s , -44d 23m 40.6s) | C | 60 | 16.2 | 36335 | 2025-01-29 02:27:58 | MASTER-SAAO | (17h 18m 14.66s , -48d 10m 39.3s) | C | 60 | 17.4 | 36414 | 2025-01-29 02:29:17 | MASTER-SAAO | (17h 30m 13.31s , -48d 09m 35.0s) | C | 60 | 17.2 | 36494 | 2025-01-29 02:30:37 | MASTER-SAAO | (17h 12m 12.99s , -44d 22m 28.4s) | C | 60 | 18.7 | 36573 | 2025-01-29 02:31:56 | MASTER-SAAO | (17h 23m 29.31s , -44d 21m 35.4s) | C | 60 | 17.9 | 36652 | 2025-01-29 02:33:16 | MASTER-SAAO | (17h 40m 59.51s , -48d 10m 37.4s) | C | 60 | 17.5 | 36732 | 2025-01-29 02:34:35 | MASTER-SAAO | (17h 53m 00.41s , -48d 09m 54.9s) | C | 60 | 17.6 | 36890 | 2025-01-29 02:37:14 | MASTER-SAAO | (17h 44m 40.86s , -44d 23m 49.2s) | C | 60 | 16.7 | 37169 | 2025-01-29 02:41:52 | MASTER-SAAO | (17h 12m 11.39s , -44d 21m 00.5s) | C | 60 | 17.1 | 37248 | 2025-01-29 02:43:11 | MASTER-SAAO | (17h 23m 24.33s , -44d 22m 58.5s) | C | 60 | 17.3 | 37327 | 2025-01-29 02:44:31 | MASTER-SAAO | (17h 41m 03.16s , -48d 09m 53.2s) | C | 60 | 17.1 | 37407 | 2025-01-29 02:45:50 | MASTER-SAAO | (17h 52m 57.89s , -48d 11m 03.2s) | C | 60 | 16.6 | 37486 | 2025-01-29 02:47:09 | MASTER-SAAO | (17h 33m 26.22s , -44d 21m 38.3s) | C | 60 | 14.9 | 37566 | 2025-01-29 02:48:29 | MASTER-SAAO | (17h 44m 44.73s , -44d 22m 56.9s) | C | 60 | 12.7 | 37645 | 2025-01-29 02:49:48 | MASTER-SAAO | (17h 47m 35.43s , -46d 17m 56.8s) | C | 60 | 15.6 | 37724 | 2025-01-29 02:51:07 | MASTER-SAAO | (17h 59m 08.69s , -46d 16m 32.3s) | C | 60 | 15.7 | 37803 | 2025-01-29 02:52:27 | MASTER-SAAO | (17h 12m 10.07s , -44d 22m 55.3s) | C | 60 | 13.4 | 37883 | 2025-01-29 02:53:46 | MASTER-SAAO | (17h 23m 26.84s , -44d 21m 42.8s) | C | 60 | 15.3 | 37962 | 2025-01-29 02:55:05 | MASTER-SAAO | (17h 40m 56.50s , -48d 10m 51.8s) | C | 60 | 15.8 | 38041 | 2025-01-29 02:56:24 | MASTER-SAAO | (17h 52m 58.20s , -48d 10m 11.0s) | C | 60 | 15.3 | 38120 | 2025-01-29 02:57:43 | MASTER-SAAO | (17h 35m 05.33s , -50d 05m 41.0s) | C | 60 | 14.7 | 38425 | 2025-01-29 03:02:48 | MASTER-SAAO | (17h 47m 37.45s , -50d 04m 32.0s) | C | 60 | 15.0 | 38662 | 2025-01-29 03:06:45 | MASTER-SAAO | (17h 12m 04.50s , -44d 22m 13.1s) | C | 60 | 16.4 | 38742 | 2025-01-29 03:08:05 | MASTER-SAAO | (17h 23m 18.76s , -44d 21m 34.3s) | C | 60 | 16.0 | 38821 | 2025-01-29 03:09:24 | MASTER-SAAO | (17h 41m 00.17s , -48d 11m 01.1s) | C | 60 | 15.7 | 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/39067. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37075] GRB 250129A: Swift detection of a burst with an optical counterpart
by GCN Circulars 29 Jan '25

29 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39066 SUBJECT: GRB 250129A: Swift detection of a burst with an optical counterpart DATE: 25/01/29 05:12:01 GMT FROM: K.L. Page at U Leicester <klp5(a)leicester.ac.uk> A. P. Beardmore (U Leicester), S. Dichiara (PSU) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team: At 04:45:09 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 250129A (trigger=1285812). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 198.689, +5.039 which is RA(J2000) = 13h 14m 45s Dec(J2000) = +05d 02' 19" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for an image trigger, the BAT light curve shows no significant peaks. The XRT began observing the field at 04:47:47.6 UT, 158.6 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source with an enhanced position: RA, Dec 198.67654, 5.03019 which is equivalent to: RA(J2000) = 13h 14m 42.37s Dec(J2000) = +05d 01' 48.7" with an uncertainty of 1.9 arcseconds (radius, 90% containment). This location is 54 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. No spectrum from the promptly downlinked event data is yet available to determine the column density. The initial flux in the 0.1 s image was 1.18e-08 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of nominal 150.000 seconds with the White filter starting 1184 seconds after the BAT trigger. There is a candidate afterglow in the list of sources generated on-board at RA(J2000) = 13:14:42.42 = 198.67673 DEC(J2000) = +05:01:50.3 = 5.03063 with a 90%-confidence error radius of about 1.10 arc sec. This position is 2.7 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.88. No correction has been made for the expected extinction corresponding to E(B-V) of 0.037. Burst Advocate for this burst is A. P. Beardmore (apb AT star.le.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/) View this GCN Circular online at https://gcn.nasa.gov/circulars/39066. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37074] Swift GRB250129.20: Global MASTER-Net OT detection
by GCN Circulars 29 Jan '25

29 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39065 SUBJECT: Swift GRB250129.20: Global MASTER-Net OT detection DATE: 25/01/29 05:08:46 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), 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 (Lomonosov MSU), O.Gress, N.Budnev(ISU), 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) was pointed to the GRB250129.20 162 sec after notice time and 240 sec after trigger time at 2025-01-29 04:49:09 UT. On our second (60s exposure) set , obtained 296 sec after tigger time at 2025-01-29 04:50:05 UT, we found 1 optical transient within Swift error-box (ra=198.683 dec=5.03833 r=0.05) brighter than 18.3. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 326 2025-01-29 04:50:05 60 (13h 14m 42.38s , +05d 01m 50.1s) 17.5 The 5-sigma upper limit has been about 18.3mag The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39065. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37073] GRB 250128B: Swift-XRT refined Analysis
by GCN Circulars 29 Jan '25

29 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39064 SUBJECT: GRB 250128B: Swift-XRT refined Analysis DATE: 25/01/29 04:02:14 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Salvaggio (INAF-OAB), M. Ferro (INAF-OAB), R. Brivio (INAF-OAB), D.N. Burrows (PSU), M. A. Williams (PSU), S. Dichiara (PSU) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 7.0 ks of XRT data for GRB 250128B, from 87 s to 33.6 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The best available XRT position (using the promptly downlinked event data, the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 231.42552, -0.53950 which is equivalent to: RA (J2000): 15 25 42.12 Dec(J2000): -00 32 22.2 with an uncertainty of 1.9 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=1.17 (+0.16, -0.14). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.0 (+0.7, -0.6). The best-fitting absorption column is 1.9 (+2.9, -1.1) x 10^21 cm^-2, consistent with the Galactic value of 8.0 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (5.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.9 (+2.9, -1.1) x 10^21 cm^-2 Galactic foreground: 8.0 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 2.0 (+0.7, -0.6) If the light curve continues to decay with a power-law decay index of 1.17, the count rate at T+24 hours will be 1.5 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.7 x 10^-15 (7.6 x 10^-15) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01285677. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/39064. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37072] GRB 250128B: Fermi GBM Observation
by GCN Circulars 28 Jan '25

28 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39063 SUBJECT: GRB 250128B: Fermi GBM Observation DATE: 25/01/28 22:42:25 GMT FROM: Ava Myers at NASA GSFC <ava.myers(a)nasa.gov> A. Myers (NPP/GSFC) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 16:22:53.77 UT on 28 January 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250128B (trigger 759774178/250128683). which was also detected by Swift BAT (P.A Evans et al. 2025, GCN [39058](https://gcn.nasa.gov/circulars/39058)). The Fermi GBM on-ground location is consistent with the Swift BAT position. The angle from the Fermi LAT boresight is 86 degrees. The GBM light curve consists of a short single emission episode with a duration (T90) of about 1.1 s (50-300 keV). The time-averaged spectrum from T0-0.8 to T0+0.4 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.0 +/- 0.5 and the cutoff energy, parameterized as Epeak, is 176 +/- 115 keV. A power law function with index -1.6 +/- 0.2 fits the spectrum equally well. The event fluence (10-1000 keV) in this time interval is (2.1 +/- 0.7)E-07 erg/cm^2. The 64-ms peak photon flux measured starting from T0-0.064 s in the 10-1000 keV band is 9 +/- 2 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/39063. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37071] GRB 250128B: GOTO optical upper limit
by GCN Circulars 28 Jan '25

28 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39062 SUBJECT: GRB 250128B: GOTO optical upper limit DATE: 25/01/28 19:52:11 GMT FROM: Ben Gompertz at U of Birmingham <b.gompertz(a)bham.ac.uk> K. Ulaczyk, D. O'Neill, G. Ramsay, B. P. Gompertz, R. Starling, M. Kennedy, K. Ackley, M. J. Dyer, J. Lyman, A. Kumar, F. Jimenez-Ibarra, D. Steeghs, D. K. Galloway, V. Dhillon, P. O'Brien, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Palle and D. Pollacco report on behalf of the GOTO collaboration: The Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022, Dyer et al. 2024) covered the field of Fermi and Swift triggered GRB 250128B (GCN 39057, 39058) at 2025-01-28 17:36:35 UT (+1.23h post-trigger). The observation was taken by GOTO-South, and consisted of 4x90s exposures in the GOTO L-band (400-700 nm). Images were processed immediately after acquisition using the GOTO pipeline. Difference imaging was performed using deeper template observations of the same pointings. Source candidates were initially filtered using a classifier (Killestein et al. 2021) and cross-matched against a variety of contextual and minor planet catalogues. We do not identify any candidate optical counterparts within the Swift XRT localisation uncertainty region, down to a 3-sigma limiting magnitude of L > 20.4 AB mag, consistent with the non-detections reported by Izzo et al. (GCN 39059) and Lipunov et al. (GCN 39061). Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction. GOTO (https://goto-observatory.org<https://goto-observatory.org/>) is a network of telescopes that is principally funded by the STFC and operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC). View this GCN Circular online at https://gcn.nasa.gov/circulars/39062. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37070] Swift GRB 250128B: Global MASTER-Net observations report
by GCN Circulars 28 Jan '25

28 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39061 SUBJECT: Swift GRB 250128B: Global MASTER-Net observations report DATE: 25/01/28 19:24:30 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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the Swift GRB 250128B ( P. A. Evans et al., GCN 39058) errorbox 8555 sec after notice time and 8574 sec after trigger time at 2025-01-28 18:45:48 UT, with upper limit up to 17.9 mag. The observations began at zenith distance = 83 deg. The sun altitude is -52.9 deg. The galactic latitude b = 43 deg., longitude l = 3 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2759219 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 8665 | MASTER-Tunka | C | 180 | 12.6 | 10262 | MASTER-Tunka | C | 90 | 13.9 | 10400 | MASTER-Tunka | C | 45 | 13.1 | 10453 | MASTER-Tunka | C | 36 | 14.1 | 10502 | MASTER-Tunka | C | 36 | 14.9 | 10550 | MASTER-Tunka | C | 30 | 14.8 | 10590 | MASTER-Tunka | C | 26 | 14.8 | 10627 | MASTER-Tunka | C | 20 | 17.9 | 10660 | MASTER-Tunka | C | 20 | 17.9 | 10693 | MASTER-Tunka | C | 20 | 17.9 | 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/39061. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37069] EP250125a: Upper limits from Swift/BAT-GUANO
by GCN Circulars 28 Jan '25

28 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39060 SUBJECT: EP250125a: Upper limits from Swift/BAT-GUANO DATE: 25/01/28 18:20:50 GMT FROM: Samuele Ronchini at PSU <sjs8171(a)psu.edu> Samuele Ronchini (PSU), James DeLaunay (PSU), Tyler Parsotan (NASA GSFC), Jamie A. Kennea (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU) report: Swift/BAT did not detect EP250125a onboard (T0: 2025-01-25T02:37:31.749 UTC, EP GCN 39028). The EP notice distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; [Tohuvavohu et al. 2020, ApJ, 900, 1](https://iopscience.iop.org/article/10.3847/1538-4357/aba94f)). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. Using the NITRATES analysis ([DeLaunay + Tohuvavohu 2022, ApJ, 941, 169](https://iopscience.iop.org/article/10.3847/1538-4357/ac9d38)), we searched for emission on 8 timescales from 0.128s to 16.384s in the interval [-20,+20] seconds around the trigger time. We find no evidence for a signal, and derive the following upper limits. We quote the 5-sigma flux upper limits in the 15-350 keV band, computed at the EP250125a position RA = 175.36337 deg , Dec = -21.71347 deg provided in GCN 39029, for three spectral templates (soft, normal, and hard GRB-like templates described in [arXiv:1612.02395]) and for four time bins. In units of 10^-7 erg/s/cm^2: |time_bin (s) |soft |normal|hard |-|-|-|- |0.256 |7.23 |5.47 | 5.08 |1.024 |3.68 |2.79 | 2.59 |4.096 |1.98 |1.50 | 1.39 |16.384 |1.21 |0.92 | 0.85 GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: [https://www.swift.psu.edu/guano/]() View this GCN Circular online at https://gcn.nasa.gov/circulars/39060. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37068] GRB 250128A: LCO optical observations
by GCN Circulars 28 Jan '25

28 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39059 SUBJECT: GRB 250128A: LCO optical observations DATE: 25/01/28 18:09:00 GMT FROM: luca.izzo(a)inaf.it L. Izzo (INAF-OACn and DARK/NBI), and D. B. Malesani (DAWN/NBI and Radboud Univ.) report: We observed the field of the short GRB 250128A (Evans et al., GCN #39058) with the Sinistro instrument mounted on the 1-m telescope of the LCO network, located at Siding Spring, Australia. Observations started on 2025 January 28 at 17:19 UT (0.95 hr after the GRB trigger). We obtained a single image of 300s in the SDSS-r and SDSS-i filters. We did not detect any source consistent with the position of the X-ray afterglow reported by Swift-XRT (Evans et al., GCN #39058) up to a limit of r = 19.4 mag and z = 18.4 mag. This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 101004719. View this GCN Circular online at https://gcn.nasa.gov/circulars/39059. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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