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

[vsnet-grb-info 38086] EP250404a: LAST detection of optical counterpart
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40063 SUBJECT: EP250404a: LAST detection of optical counterpart DATE: 25/04/04 18:17:33 GMT FROM: Ruslan Konno at Weizmann Institute of Science <ruslan.konno(a)desy.de> R. Konno (WIS), S. Garrappa (WIS), E. A. Zimmerman (WIS), A. Horowicz (WIS), E. O. Ofek (WIS), S. Ben-Ami (WIS), D. Polishook (WIS), O. Yaron (WIS), P. Chen (WIS), A. Krassilchtchikov (WIS), Y. M. Shani (WIS), E. Segre (WIS), A. Gal-Yam (WIS), S. Spitzer (WIS), and K. Rybicki (WIS) on … [View More]

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[vsnet-grb-info 38085] GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40062 SUBJECT: GRB 250402A: Swift/BAT-GUANO localization skymap of a burst DATE: 25/04/04 18:11:36 GMT FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com> James DeLaunay (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 250402A onboard (T0: 2025-04-02T23:08:01.467 UTC, SVOM trig sb25040203, Fermi trig 765328094) The Fermi … [View More]and SVOM notices, 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). 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. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 8.2 in a 4.096 s analysis time bin, starting at T0 + 7.168 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2025. in prep) The 90% credible area is 5,905 deg2 and the 50% credible area is 1,632 deg2. The integrated probability inside the coded field of view is 1%. The NITRATES skymap is consistent with the SVOM/ECLAIRS position (GCN 40014), and the afterglow position (SVOM/VT GCN 40015, SVOM/MXT GCN 40019, LCO GCN 40020, SVOM/COLIBRI GCN 40023, Swift/XRT GCN 40027, EP/FXT GCN 40040, Mondy GCN 40049) A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=765328116/#:~:te… The probability skymap file can be downloaded from the link here [skymap_fits_file](https://guano.swift.psu.edu/files/765328116/0_n_PROBMAP) Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=765328116 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/40062. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

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[vsnet-grb-info 38084] EP250404a: Xinglong-2.16m spectroscopic redshift
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40061 SUBJECT: EP250404a: Xinglong-2.16m spectroscopic redshift DATE: 25/04/04 18:05:48 GMT FROM: Dong Xu at NAOC/CAS <dxu(a)nao.cas.cn> Z.P. Zhu, J. An, X. Liu, S.Q. Jiang, J.J. Jin, Z. Fan, D. Xu (NAOC), S.Y. Fu (HUST), report on behalf of a large collaboration: We carried out spectroscopy of the optical counterpart (e.g., Jiang et al., GCN 40052; Perez-Garcia et al., GCN 40053; Du et al., GCN 40058) of EP250404a (Hu et al., GCN 40051), likely the … [View More]

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[vsnet-grb-info 38083] GRB 250403A: Fermi GBM observations
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40060 SUBJECT: GRB 250403A: Fermi GBM observations DATE: 25/04/04 16:31:50 GMT FROM: Peter Veres at University of Alabama in Huntsville <veresp(a)gmail.com> P. Veres (UAH), M. Godwin (UAH), C. Meegan (UAH) and E. Bissaldi (Politecnico and INFN Bari) report on behalf of the Fermi GBM Team: "At 15:15:22.83 UT on 03 April 2025, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 250403A (trigger 765386127 / 250403636). This GRB was also … [View More]

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[vsnet-grb-info 38082] GRB 250327B: VIRT Optical Upper Limit
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40059 SUBJECT: GRB 250327B: VIRT Optical Upper Limit DATE: 25/04/04 16:21:28 GMT FROM: Priya Gokuldass at ERAU <gokuldap(a)my.erau.edu> K. Smith (UVI), P. Gokuldass (ERAU), N. Orange (OrangeWave Innovative Science, LLC), B. Gendre (UVI), D. Morris (NASA), T. Lombardi (Eckerd College), F. George (ERAU), D. Smith (UVI), C. Watson (UVI) report: We observed the field of GRB 250327B (Bouchet et al., GCN 39888) detected by SVOM/ECLAIRs with the 0.5m Virgin … [View More]

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[vsnet-grb-info 38081] EP250404a: Mephisto multi-band optical detection
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40058 SUBJECT: EP250404a: Mephisto multi-band optical detection DATE: 25/04/04 16:19:08 GMT FROM: Chenxu Liu at Mephisto Team <cxliu(a)ynu.edu.cn> Guowang Du, Ziwei Li, Chenxu Liu, Dezi Liu, Yaosong Yu, Chenxi Shang, Jinghua Zhang, Yuan Fang, Xufeng Zhu, Tao Wang, Xinlei Chen, Xingzhu Zou, Yu Pan, Brajesh Kumar, Yuanpei Yang, Xiangkun Liu, Xiaowei Liu (all SWIFAR, YNU) report on behalf of the Mephisto Team: We performed simultaneous multi-band … [View More]

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[vsnet-grb-info 38080] GRB 250331C Swift-BAT refined analysis
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40057 SUBJECT: GRB 250331C Swift-BAT refined analysis DATE: 25/04/04 16:17:44 GMT FROM: Mike Moss at NASA GSFC <mikejmoss3(a)gmail.com> A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec … [View More]

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[vsnet-grb-info 38079] GRB 250331B Swift-BAT refined analysis
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40056 SUBJECT: GRB 250331B Swift-BAT refined analysis DATE: 25/04/04 16:16:25 GMT FROM: Mike Moss at NASA GSFC <mikejmoss3(a)gmail.com> S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+842 … [View More]

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[vsnet-grb-info 38078] GRB 250331B Swift-BAT refined analysis
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40056 SUBJECT: GRB 250331B Swift-BAT refined analysis DATE: 25/04/04 16:16:25 GMT FROM: Mike Moss at NASA GSFC <mikejmoss3(a)gmail.com> S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+842 … [View More]

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[vsnet-grb-info 38077] GRB 250403A: Swift/UVOT Detection
by GCN Circulars 04 Apr '25

04 Apr '25

TITLE: GCN CIRCULAR NUMBER: 40048 SUBJECT: GRB 250403A: Swift/UVOT Detection DATE: 25/04/04 13:28:59 GMT FROM: Sam Shilling at Lancaster University <shilling.sam(a)gmail.com> S. P. R. Shilling (Lancaster U.), S. R. Oates (Lancaster U.) and S. Dichiara (PSU) report on behalf of the Swift UVOT team: Swift/UVOT observed the field of GRB 250403A detected by Fermi GBM (Fermi team, GCN Circ. 40025) and SVOM/ECLAIRs (Julakanti et al., GCN Circ. 40026), starting at 17:22:59 UT on 24/04/… [View More]

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