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

[vsnet-grb-info 37156] GRB 250129A: Swift-BAT refined analysis
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39147 SUBJECT: GRB 250129A: Swift-BAT refined analysis DATE: 25/02/04 20:36:28 GMT FROM: Rahul Gupta at NASA GSFC <rahul.gupta(a)nasa.gov> C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), 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-571 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 250129A (trigger #1285812) (Beardmore, et al., GCN Circ. 39066). The BAT ground-calculated position is RA, Dec = 198.708, 5.029 deg which is RA(J2000) = 13h 14m 49.8s Dec(J2000) = +05d 01' 44.9" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 84%. The mask-weighted BAT light curve exhibits a multi-peaked and complex structure, with the most prominent peak occurring at approximately T0 + 184 seconds. T90 (15-350 keV) is 262.25 +- 23.71 sec (estimated error including systematics). The time-averaged spectrum from T-64.39 to T+302.62 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.17 +- 0.09. The fluence in the 15-150 keV band is 5.0 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+184.12 sec in the 15-150 keV band is 1.4 +- 0.2 ph/cm2/sec. 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/1285812 View this GCN Circular online at https://gcn.nasa.gov/circulars/39147. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37155] EP 250108A: Upper limits from Fermi-GBM Observations
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39146 SUBJECT: EP 250108A: Upper limits from Fermi-GBM Observations DATE: 25/02/04 19:53:01 GMT FROM: mariaedvige.ravasio(a)ru.nl M. E. Ravasio (Radboud Univ.), E. Burns (LSU), Colleen Wilson-Hodge (NASA Marshall Space Flight Center) and P.G. Jonker (Radboud Univ.) report on behalf of the Fermi-GBM Team: The location of the EP-WXT event EP250108A (Li et al., GCN 38861) was occulted by the Earth for Fermi at the EP trigger time T0=2025-01-08T12:30:28.34 UTC. There was no Fermi-GBM onboard trigger around EP-WXT times. The location becomes visible at around ~T0+415 s. The GBM targeted search [1], the most sensitive, coherent search for GRB-like signals, was run in the time interval [-50;+500] s centred at different times, from T0 up to T0+2500s, to cover the whole reported duration of the EP transient, seeking signals between 64 ms and 32.768 s in duration. A transient was found at ~T0+500 s, but its localization is consistent with the Crab nebula, which exited Earth occultation at that time. No signal consistent with the EP transient both temporally and spatially is identified, as confirmed by visual inspection of the data. Assuming a “soft” spectral template (Band function with Epeak = 70 keV, alpha = -1.9, beta = -3.7), and a duration of 8.192 s, the most conservative sky-averaged upper limit is found in the time interval [T0+1450; T0+2000] s, corresponding to a flux of 2.6e-08 erg/cm2/s in the energy band 10-1000 keV. [1] Goldstein et al. 2019 arXiv:1903.12597 View this GCN Circular online at https://gcn.nasa.gov/circulars/39146. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37154] IPN triangulation of GRB 250204B (short/hard)
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39145 SUBJECT: IPN triangulation of GRB 250204B (short/hard) DATE: 25/02/04 17:51:38 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, 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, G. Waratkar, J.Joshi, V. Bhalerao, D. Bhattacharya, and S. Vadawale, on behalf of the Astrosat-CZTI team, report: The short-duration GRB 250204B (Fermi-GBM detection: The Fermi GBM team, GCN 39141; AstroSat-CZTI detection: Dasgupta et al., GCN 39142) was detected by Fermi (GBM trigger 760344078), AstroSat (CZTI), Swift (BAT), Konus-Wind, and INTEGRAL (SPI-ACS) at about 24074 s UT (06:41:14). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 1.945 (00h 07m 47s) +35.469 (+35d 28' 07") Corners: 4.715 (00h 18m 52s) +29.985 (+29d 59' 08") 6.110 (00h 24m 26s) +29.936 (+29d 56' 11") 358.613 (23h 54m 27s) +40.986 (+40d 59' 08") 356.896 (23h 47m 35s) +41.060 (+41d 03' 34") --------------------------------------------- The error box area is 13.4 sq. deg, and its maximum dimension is 13.4 deg (the minimum one is 1 deg). The Sun distance was 64 deg. This localization may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM localization (GCN 39141). A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB250204_T24073/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/39145. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37153] IPN triangulation of GRB 250202B
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39144 SUBJECT: IPN triangulation of GRB 250202B DATE: 25/02/04 17:46:35 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, 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, G. Waratkar, J.Joshi, V. Bhalerao, D. Bhattacharya, and S. Vadawale, on behalf of the Astrosat-CZTI team, and S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, report: The bright long-duration GRB 250202B (Fermi-GBM detection: The Fermi GBM team, GCN 39120; Bala et al., GCN 39133; AstroSat-CZTI detection: Srijan et al., GCN 39122; NuSTAR-ACS detection: Grefenstette, GCN 39135) was detected by Fermi (GBM trigger 760161442), AstroSat (CZTI), Swift (BAT), Konus-Wind, and INTEGRAL (SPI-ACS) at about 14237 s UT (03:57:17). The burst was outside the coded field of view of the BAT. We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 344.999 (22h 60m 00s) +19.593 (+19d 35' 35") Corners: 343.557 (22h 54m 14s) +22.051 (+22d 03' 04") 347.168 (23h 08m 40s) +17.149 (+17d 08' 56") 346.317 (23h 05m 16s) +17.129 (+17d 07' 44") 342.644 (22h 50m 34s) +22.024 (+22d 01' 27") --------------------------------------------- The error box area is 4.1 sq. deg, and its maximum dimension is 6.5 deg (the minimum one is 41.5 arcmin). The Sun distance was 45 deg. This localization may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM (GCN 39120) localization. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB250202_T14235/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/39144. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37152] LIGO/Virgo/KAGRA S250204ax: Updated Sky localization
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39143 SUBJECT: LIGO/Virgo/KAGRA S250204ax: Updated Sky localization DATE: 25/02/04 17:06:49 GMT FROM: Will Farr <will.farr(a)stonybrook.edu> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further analysis of the LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S250204ax (GCN Circular 39137). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S250204ax For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 318 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2056 +/- 690 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] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. (2023) arXiv:2307.13380 View this GCN Circular online at https://gcn.nasa.gov/circulars/39143. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37151] GRB 250204B: AstroSat CZTI detection of a short burst
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39142 SUBJECT: GRB 250204B: AstroSat CZTI detection of a short burst DATE: 25/02/04 16:30:31 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> A. Dasgupta (BITS Pilani, Hyderabad), 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 short-duration GRB 250204B which was also detected by Fermi/GBM (Fermi-GBM Team, GCN Circ. 39141). Inspection of INTEGRAL/SPI-ACS data also showed the detection of the burst. The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2025-02-04 06:41:14.050 UTC. The measured peak count rate associated with the burst is 446 (+149, -49) counts/s above the background in the combined data of two (out of four) quadrants, with a total of 237 (+60, -71) counts. The local mean background count rate was 116 (+6, -8) counts/s. Using cumulative rates, we measure a T90 of 1.1 (+0.3, -0.5) s. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2025-02-04 06:41:13.502 UTC. The measured peak count rate is 300 (+70, -41) counts/s above the background in the combined Veto data of all quadrants, with a total of 659 (+172, -189) counts. The local mean background count rate was 1265 (+8, -8) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 from it. 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/39142. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37150] GRB 250204B: Fermi GBM Final Localization
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39141 SUBJECT: GRB 250204B: Fermi GBM Final Localization DATE: 25/02/04 14:58:59 GMT FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz> The Fermi GBM team reports the detection of a likely LONG GRB At 06:41:14.00 UT on 04 February 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250204B (trigger 760344078/250204279). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 2.35, Dec = 29.70 (J2000 degrees, equivalent to J2000 0h 9m, +29d 41'), with a statistical uncertainty of 2.80 degrees. The angle from the Fermi LAT boresight is 124 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250204279/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250204279/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250204279/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39141. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37149] GRB 250129A: LCO late afterglow detection
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39140 SUBJECT: GRB 250129A: LCO late afterglow detection DATE: 25/02/04 11:47:57 GMT FROM: Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf(a)iac.es> I. Pérez-Fournon (IAC and ULL), F. Poidevin (IAC and ULL), D. Cano-Morales (ULL), I. Correa-Plasencia (ULL), and A.E. Hernández-Díaz (ULL) We observed the field of the Swift GRB 250129A (Beardmore et al., GCN Circ. 39066) with one of the Las Cumbres Observatory Global Telescope network (LCOGT) 1-m telescopes equipped with a Sinistro camera at the LCOGT node at the Cerro Tololo Inter-American Observatory (Chile). We obtained a single 300-sec image in the SDSS-r' filter starting at 2025-02-03 07:35:39 UT, approximately 5.118 days after the trigger. The optical transient detected by Swift UVOT (Beardmore et al., GCN Circ. 39066) is clearly detected with a magnitude of r' = 22.04 +/- 0.21, calibrated against PanSTARRS stars and not corrected for extinction. The optical brightness of the afterglow is consistent with the results of late-time observations by Bochenek and Perley (GCN Circ. 39131) and Watson et al. (GCN Circ. 39136). This work makes use of observations from the Las Cumbres Observatory global telescope network (LCOGT observing programme IAC2025A-009, SGLF). View this GCN Circular online at https://gcn.nasa.gov/circulars/39140. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37148] GRB 250129A: AbAO AS-32 and Mondy AZT-33IK optical observations
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39139 SUBJECT: GRB 250129A: AbAO AS-32 and Mondy AZT-33IK optical observations DATE: 25/02/04 07:44:31 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 the IKI-GRB-FuN collaboration: We performed optical observations of the field of GRB 250129A (Beardmore et. al, GCN 39066; 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; Ghosh et. al, GCN 39077; Schneider et. al, GCN 39078; Brivio et. al, GCN 39079; Goad et. al, GCN 39082; Siegel, GCN 39085; Osborne et. al, GCN 39089; Zheng et. al, GCN 39090; Schlekat et. al, GCN 39091; Antier et. al, GCN 39096; Odeh et. al, GCN 39097; Ferro et. al, GCN 39098; Malesani et. al, GCN 39100; Romanov, GCN 39101; Zheng et. al, GCN 39102; Watson et. al, GCN 39104; Watson et. al, GCN 39105; Akl et. al, GCN 39106; Moskvitin et. al, GCN 39107; Calapai et. al, GCN 39109; Schlekat et. al, GCN 39110; Gompertz et. al, GCN 39114; Ror et. al, GCN 39115; Frederiks et. al, GCN 39116; Wu et. al, GCN 39124; Paek et. al, GCN 39129) in the R filter 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 Observatory (AbAO). The observations began on 2025-01-30 at 22:16:50 UT, i.e. ~1.76 days since trigger. The optical counterpart is well detected in the stacked images from both observatories. The preliminary photometry is as follows: Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) Telescope (mid, days) (s) 2025-01-30 22:16:50 1.76610 103*60 R 19.46 0.21 22.0 AS-32 2025-01-31 19:38:51 2.65188 45*120 R 20.38 0.08 23.0 AZT-33IK 2025-02-01 19:32:02 3.64507 42*120 R 20.82 0.11 22.9 AZT-33IK The photometry is based on nearby stars of the USNO-B1.0 catalog (R2 magnitudes) and have not been corrected for the Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/39139. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37147] GRB 250204A: Fermi GBM Final Real-time Localization
by GCN Circulars 04 Feb '25

04 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39138 SUBJECT: GRB 250204A: Fermi GBM Final Real-time Localization DATE: 25/02/04 07:38:50 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 07:28:17 UT on 4 Feb 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250204A (trigger 760346902.4098 / 250204311). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 108.2, Dec = -23.8 (J2000 degrees, equivalent to J2000 07h 12m, -23d 48'), with a statistical uncertainty of 1.1 degrees. The angle from the Fermi LAT boresight is 9.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250204311/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250204311/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250204311/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39138. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

2025

2024

2023

2022

2021

vsnet-grb-info February 2025