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

[vsnet-grb-info 37136] The EP-WXT trigger 01709131196 is likely a flaring star
by GCN Circulars 03 Feb '25

03 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39127 SUBJECT: The EP-WXT trigger 01709131196 is likely a flaring star DATE: 25/02/03 01:44:35 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> H. Zhou (PMO, CAS), M.Q. Huang (USTC), X. Mao and Z.-X. Ling (NAOC, CAS) report on behalf of the Einstein Probe team: The EP-WXT trigger (ID: 01709131196) on 2025-02-02T21:33:52 (UTC) is likely a stellar flare associated with a M-type star RX J0916.1+0153. The preliminary X-ray luminosity (0.5-10keV) is about 5.4 x 10^29 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/39127. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37135] GRB 250202C: Fermi GBM Final Real-time Localization
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39126 SUBJECT: GRB 250202C: Fermi GBM Final Real-time Localization DATE: 25/02/02 20:18:40 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 20:10:35 UT on 2 Feb 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250202C (trigger 760219840.823694 / 250202841). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 300.9, Dec = -54.5 (J2000 degrees, equivalent to J2000 20h 03m, -54d 30'), with a statistical uncertainty of 4.0 degrees. The angle from the Fermi LAT boresight is 25.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202841/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202841/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202841/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39126. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37134] LIGO/Virgo/KAGRA S250202cu: Identification of a GW compact binary merger candidate
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39125 SUBJECT: LIGO/Virgo/KAGRA S250202cu: Identification of a GW compact binary merger candidate DATE: 25/02/02 20:04:16 GMT FROM: Sivananda Thondapu <sivananda.thondapu(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S250202cu during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2025-02-02 18:49:02.510 UTC (GPS time: 1422557360.510). The candidate was found by the CWB BBH [1], GstLAL [2], and MBTA [3] analysis pipelines. S250202cu is an event of interest because its false alarm rate, as estimated by the online analysis, is 1.5e-08 Hz, or about one in 2 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S250202cu The classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), NSBH (<1%), or BNS (<1%). Varying broadband noise in the LIGO Hanford detector was present at the time of the event, which may affect the parameters or the significance of the candidate. Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [4] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [4] Both HasNS and HasRemnant consider the support of several neutron star equations of state. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is 4%. Two sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.multiorder.fits,0, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 30 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 4327 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 5526 +/- 1810 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] T. Mishra et al. PRD 105, 083018 (2022) doi:10.1103/PhysRevD.105.083018 [2] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 View this GCN Circular online at https://gcn.nasa.gov/circulars/39125. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37133] GRB 250129A: SVOM/C-GFT optical observations
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39124 SUBJECT: GRB 250129A: SVOM/C-GFT optical observations DATE: 25/02/02 11:25:12 GMT FROM: Chao Wu at NAOC <cwu(a)nao.cas.cn> Chao WU (NAOC), Zhe Kang (CHO), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC), Yulei, Qiu(NAOC), Jing Wang(NAOC), Jianyan Wei (NAOC) report on behalf of the SVOM/C-GFT team: We observed the field of GRB 250129A detected by Swift/BAT (Beardmore et al., GCN 39066) with C-GFT. Our observations were started on 2025-01-30T17:51:44 UTC, ~37.11 hr after the trigger. A series of g, r and i band images were obtained with exposure time of 30s for each image. The optical counterpart (Beardmore et al., GCN 39066; Francile et al., GCN 39065; Lipunov et al., GCN 39070; Schneider et al., GCN 39071; Belkin et al., GCN 39072; Izzo et al., GCN 39073; Izzo et al., GCN 39074; Francile et al., GCN 39075; Ghosh et al., GCN 39077; Schneider et al., GCN 39078; Brivio et al.,GCN 39079; Siegel et al.,GCN 39085; Zheng et al., GCN 39090; Schlekat et al., GCN39091; Antier et al., GCN 39096; Odeh et al. GCN 39097; Ferroet al. GCN 39098; Bochenek et al., GCN 39099; Malesani et al., GCN 39100; Romanov et al., GCN 39101; Zheng et al., GCN 39102; Watson et al., GCN 39104;Vinko et al., GCN 39105; Akl et al., GCN 39106; Moskvitin et al., GCN 39107; Giovanni et al., GCN 39109; Schlekat et al., GCN 39110; Schlekat et al., GCN 39114 and Ror et al., GCN 39115) was clearly detected in stacked images of band g,r and i. The results are, (T-T0)_mid(hr) mag mag_err band ----------------------------------------- 37.73 20.08 0.22 g 37.83 19.74 0.16 r 37.92 19.32 0.11 i The photometry was calibrated with nearby Pan-STARRS1 stars. We thank the observation assistants Bowen Li and Yinghuai Hao at Jilin observatory for their excellent support. Chinese Ground Follow-up Telescope of SVOM mission is located at Jilin, Changchun Observatory, National Astronomical Observatories, CAS. It has FOV of 1.28 deg x 1.28 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope. View this GCN Circular online at https://gcn.nasa.gov/circulars/39124. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37132] The EP-WXT trigger 01709131153 is not a real source
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39123 SUBJECT: The EP-WXT trigger 01709131153 is not a real source DATE: 25/02/02 10:50:26 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y. L. Wang, W. J. Zhang, W. X. Wang, Y. Liu (NAO, CAS) report on behalf of the Einstein Probe team: Further analysis of the data suggests that the EP-WXT on-board trigger 01709131153 at 2025-02-02T09:47:53.499 (UTC) is not a real source. View this GCN Circular online at https://gcn.nasa.gov/circulars/39123. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37131] GRB 250202B: AstroSat CZTI detection of a bright long GRB
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39122 SUBJECT: GRB 250202B: AstroSat CZTI detection of a bright long GRB DATE: 25/02/02 08:46:15 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> S. Srijan (IITB), G. Waratkar (IITB), J. Joshi (IUCAA), 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 bright long GRB 250202B which was also detected by Fermi/GBM (Fermi-GBM Team, GCN Circ. 39120). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2025-02-02 03:57:18.0 UTC. The measured peak count rate associated with the burst is 485 (+14, -15) counts/s above the background in the combined data of all quadrants, with a total of 21162 (+462, -483) counts. The local mean background count rate was 262 (+2, -2) counts/s. Using cumulative rates, we measure a T90 of 91 (+2, -2) s. In the preliminary analysis, we find 2474 Compton events associated with this event. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2025-02-02 03:57:24.5 UTC. The measured peak count rate is 750 (+7, -8) counts/s above the background in the combined Veto data of all quadrants, with a total of 30918 (+312, -410) counts. The local mean background count rate was 1195 (+1, -1) counts/s. We measure a T90 of 90 (+1, -1) s from the cumulative Veto light curve. 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/39122. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37130] LIGO/Virgo/KAGRA S250202ad: Retraction of GW compact binary merger candidate
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39121 SUBJECT: LIGO/Virgo/KAGRA S250202ad: Retraction of GW compact binary merger candidate DATE: 25/02/02 04:44:54 GMT FROM: Souradeep Pal at IISER Kolkata <sp19rs015(a)iiserkol.ac.in> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: The trigger S250202ad is no longer considered to be a candidate of interest. This candidate was initially identified by one or more early-warning analyses by matching partial signal templates to the data. Analysis of additional data up to the putative merger time, with full signal templates, did not make a significant detection, indicating that the initial candidate was likely due to transient noise. View this GCN Circular online at https://gcn.nasa.gov/circulars/39121. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37129] GRB 250202B: Fermi GBM Final Real-time Localization
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39120 SUBJECT: GRB 250202B: Fermi GBM Final Real-time Localization DATE: 25/02/02 04:07:47 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 03:57:17 UT on 2 Feb 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250202B (trigger 760161442.322744 / 250202165). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 347.8, Dec = 16.5 (J2000 degrees, equivalent to J2000 23h 11m, 16d 30'), with a statistical uncertainty of 1.4 degrees. The angle from the Fermi LAT boresight is 128.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202165/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202165/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202165/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39120. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37128] Swift GRB250129A: MASTER 4 days observations report
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39119 SUBJECT: Swift GRB250129A: MASTER 4 days observations report DATE: 25/02/02 03:23:05 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, N.Tiurina, P.Balanutsa, I.Panchenko, K.Zhirkov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, Ya.Kechin, V.Senik, V.Topolev, A.Chasovnikov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), D.Buckley (SAAO), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), 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) The MASTER-OAFA All Sky Camera located in Argentina (OAFA observatory of San Juan National University) imaged SWIFT GRB 250129A (A. P. Beardmore et al., GCN 39066) errorbox with upper limit up to ~8 mag (V) at single 5-s images with _prompt_ limit ~10 mag. MASTER-OAFA Very Wide Field Camera (VWFC, MASTER-ShOK camera of Global MASTER-Net: http://observ.pereplet.ru, Lipunov, Korniov, Gorbovskoy, Tiurina & Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 626 pp.) located in Argentina (OAFA observatory of San Juan National University) was pointed to the SWIFT GRB 250129A ( A. P. Beardmore et al., GCN 39066) errorbox 185 sec after trigger time at 2025-01-29 04:48:14 UT, with upper limit up to ~15 mag. MASTER500-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru) located in Argentina (OAFA observatory of San Juan National University) was pointed to the SWIFT GRB 250129A (Francile et al., GCN 39065) errorbox 160 sec after notice time (240sec after trigger time) at 2025-01-29 04:49:09 UT, with upper limit up to 21.1 mag. The observations began at zenith distance = 73 deg. (the sun altitude was -41.0 deg.) and were condinued at 30, 31 Jan, 01, 02, 03 Feb. MASTER600-Tunka robotic telescope located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the SWIFT GRB 250129A errorbox 40114 sec after notice time (40194 sec after trigger time) at 2025-01-29 15:55:03 UT, with upper limit up to 21.0 mag. The observations began at zenith distance = 85 deg (the sun altitude was -52.8 deg.) and were continued at 30, 31 Jan, 01, 02 Feb 2025. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the SWIFT GRB 250129A errorbox 55139 sec after notice time (55220 sec after trigger time) at 2025-01-29 20:05:29 UT, with upper limit up to 18.9 mag. The observations began at zenith distance = 83 deg. The sun altitude was -59.8 deg. Observations were continued observations at 30, 31 Jan, 01, 02 Jan. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) was pointed to the SWIFT GRB 250129A errorbox 62515 sec after notice time (62595 sec after trigger time) at 2025-01-29 22:08:24 UT, with upper limit up to 20.2 mag. The observations began at zenith distance = 81 deg. The sun altitude is -39.2 deg. MASTER OT J131442.41+050150.4 presents from 29 jan (240s after trigger time) up to now (~21.5m, unfiltered) all 4 days with light curve with complicated structure . The galactic latitude b = 67 deg., longitude l = 319 deg. Real time updated cover map and discovered OT are available here: https://master.sai.msu.ru/site/master2/observ.php?id=2760136 View this GCN Circular online at https://gcn.nasa.gov/circulars/39119. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37127] GRB 250202A: Fermi GBM Final Real-time Localization
by GCN Circulars 02 Feb '25

02 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39118 SUBJECT: GRB 250202A: Fermi GBM Final Real-time Localization DATE: 25/02/02 01:18:35 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 01:08:03 UT on 2 Feb 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250202A (trigger 760151288.464456 / 250202047). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 295.3, Dec = -35.0 (J2000 degrees, equivalent to J2000 19h 41m, -35d 00'), with a statistical uncertainty of 9.0 degrees. The angle from the Fermi LAT boresight is 36.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202047/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202047/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202047/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39118. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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