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

[vsnet-grb-info 36997] LIGO/Virgo/KAGRA S250119cv: NED Galaxies in the Localization Volume
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38989 SUBJECT: LIGO/Virgo/KAGRA S250119cv: NED Galaxies in the Localization Volume DATE: 25/01/19 20:44:54 GMT FROM: David Cook at Caltech/IPAC-NED <dcook(a)ipac.caltech.edu> David O. Cook (Caltech/IPAC), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), Joseph M. Mazzarella (Caltech/IPAC), Marion Schmitz (Caltech/IPAC), and Leo Singer (NASA/GSFC) On behalf of the NASA/IPAC Extragalactic Database (NED) Team. We spatially cross-matched the LVK S250119cv-3-Initial sky localization with the NED Local Volume Sample (NED-LVS; Cook et al. 2023), which is a subset of NED with a redshift or redshift-independent distance less than 1000 Mpc. We find 608 galaxies within the 90% containment volume, and we list here the top 20 galaxies sorted by the joint probability of the 3D localization and the WISE W1 luminosity (an observable proxy for stellar mass). For the full or top 20 list of galaxies in the 90% volume go either to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/ or click on the following links: Full List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250119cv/3 Top 20 List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250119cv/3/20 The NED-GWF service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic follow-up observations. The NED top 20 list is sorted by the joint probability of the 3D localization and the WISE W1 luminosity, but users can sort on additional pre-computed prioritization metrics (star formation rate, P_3D * P_SFR; and specific star formation rate, P_3D * P_sSFR; etc.) which are available via downloading the entire galaxy list inside the event's probability volume. | objname| ra| dec|objtype| DistMpc|DistMpc_unc| m_NUV| m_NUV_unc| m_Ks| m_Ks_unc| m_W1| m_W1_unc| P_3D|P_3D_LumW1| |-------------------------|--------------|--------------|-------|-----------|-----------|------------|------------|------------|------------|------------|------------|--------|----------| |WISEA J010052.08+272244.7| 15.21700| 27.37903| G| 412.82| null| null| null| 13.063| 0.160| 9.482| 0.006|2.68e-06| 1.23e-07| |WISEA J005734.00+265543.4| 14.39158| 26.92878| G| 310.80| null| null| null| 13.442| 0.147| 11.227| 0.007|6.10e-06| 3.18e-08| |WISEA J004900.74+271437.7| 12.25312| 27.24382| IrS| 486.42| null| null| null| 13.943| 0.140| 11.573| 0.007|2.46e-06| 2.28e-08| |WISEA J005638.99+285344.8| 14.16246| 28.89581| G| 358.17| null| 20.378| 0.203| 13.419| 0.074| 10.380| 0.006|1.26e-06| 1.90e-08| |WISEA J005359.99+271503.0| 13.50000| 27.25086| G| 411.22| 0.10| null| null| 13.288| 0.141| 13.011| 0.017|9.95e-06| 1.76e-08| |WISEA J005416.61+280547.4| 13.56917| 28.09650| G| 493.98| null| null| null| 13.645| 0.163| 13.208| 0.024|7.38e-06| 1.56e-08| |WISEA J005121.10+272804.5| 12.83800| 27.46778| G| 422.60| null| 21.151| 0.304| 12.957| 0.115| 12.853| 0.014|6.96e-06| 1.50e-08| | UGC 00535| 13.13108| 26.13222| G| 220.59| 0.09| null| null| 11.661| 0.089| 10.301| 0.006|2.34e-06| 1.44e-08| |WISEA J005455.41+284308.6| 13.73092| 28.71911| G| 492.28| 0.15| null| null| 13.138| 0.150| 12.691| 0.013|4.18e-06| 1.42e-08| |WISEA J005611.18+272126.2| 14.04667| 27.35733| G| 420.81| null| null| null| 13.468| 0.140| 13.351| 0.024|1.03e-05| 1.40e-08| |WISEA J005522.22+273458.8| 13.84267| 27.58306| G| 546.38| 0.09| 20.390| 0.291| 13.821| 0.188| 13.423| 0.017|6.54e-06| 1.39e-08| |WISEA J005908.17+265707.9| 14.78412| 26.95225| G| 309.35| null| null| null| 13.456| 0.163| 11.695| 0.007|3.88e-06| 1.31e-08| |WISEA J005439.87+281009.8| 13.66575| 28.16906| G| 448.78| null| 20.604| 0.225| 13.617| 0.169| 13.248| 0.018|7.52e-06| 1.27e-08| |WISEA J005530.30+274200.2| 13.87629| 27.70008| IrS| 545.80| 0.03| null| null| 13.778| 0.164| 13.553| 0.025|6.59e-06| 1.24e-08| |WISEA J004703.00+270038.7| 11.76246| 27.01083| G| 325.40| null| 19.853| 0.133| 12.937| 0.135| 11.032| 0.006|1.82e-06| 1.24e-08| |WISEA J005515.68+275512.4| 13.81533| 27.92003| G| 393.72| 0.08| null| null| 13.807| 0.194| 13.123| 0.013|8.21e-06| 1.20e-08| | NGC 0326| 14.59458| 26.86528| GPair| 211.54| 0.92| null| null| null| null| 10.233| 0.007|1.96e-06| 1.19e-08| |WISEA J005642.85+265022.8| 14.17850| 26.83967| G| 325.92| null| null| null| 12.596| 0.108| 12.654| 0.010|7.31e-06| 1.13e-08| |WISEA J005714.88+274253.8| 14.31200| 27.71489| G| 404.88| 0.04| null| null| 13.679| 0.093| 13.234| 0.025|7.94e-06| 1.11e-08| |WISEA J005413.03+271750.3| 13.55433| 27.29731| G| 444.44| null| null| null| 13.625| 0.156| 13.660| 0.025|9.75e-06| 1.11e-08| Table 1: Top 20 galaxies in NED-LVS that fall in the 90% probability volume for S250119cv sorted by the joint probability of 3D position and WISE W1 luminosity (P_3D * P_LumW1). Galaxy is the NED preferred name. RA and Dec are the Equatorial coordinates in degrees (J2000). Objtype is the object type of the galaxy candidate. Distance is the distance to the galaxy in Mpc. m_NUV and mErr_NUV are the apparent magnitude and error from GALEX. m_Ks and mErr_Ks are the apparent magnitude and error from 2MASS. m_W1 and mErr_W1 are the apparent magnitude and error from AllWISE. P_3D is the probability that the galaxy is in the volume given the distance of GW event. P_3D_LumW1 is the joint probability within the volume weighted by the WISE1 luminosity of the galaxy (P_3D * P_LumW1). View this GCN Circular online at https://gcn.nasa.gov/circulars/38989. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36996] GRB 250117A: Swift/BAT-GUANO localization skymap of a short burst
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38988 SUBJECT: GRB 250117A: Swift/BAT-GUANO localization skymap of a short burst DATE: 25/01/19 20:21:11 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 250117A onboard (T0: 2025-11-17T20:21:57.89 UTC, Fermi trig 758838122, GECAM GCN 38982) The Fermi 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). 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 17.2 in a 0.128 s analysis time bin, starting at T0 + 0.288 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 2,585 deg2 and the 50% credible area is 143 deg2. The integrated probability inside the coded field of view is <1%. The NITRATES skymap is consistent with the Fermi localization reported in the final position notice and the GECAM-B localization (GCN 38982). A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=758838152/#:~:te… The probability skymap file can be downloaded from the link here [skymap_fits_file](https://guano.swift.psu.edu/files/758838152/0_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=758838152 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/38988. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36995] EP250108a / SN2025kg: Gemini GMOS-S confirmation of an associated broad-lined SN Ic
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38987 SUBJECT: EP250108a / SN2025kg: Gemini GMOS-S confirmation of an associated broad-lined SN Ic DATE: 25/01/19 19:44:15 GMT FROM: Andrew Levan at Radboud University <a.levan(a)astro.ru.nl> Andrew J. Levan (Radboud), Jillian C. Rastinejad (Northwestern), Daniele B. Malesani (DAWN/ NBI and Radboud), Wen-fai Fong (Northwestern), Nial R. Tanvir (Leicester), P.G. Jonker (Radboud), Rob A. J. Eyles-Ferris (Leicester) report on behalf of a larger collaboration: We obtained spectroscopic observations of the optical counterpart AT2025kg (“the kangaroo”; Eyles-Ferris, GCN 38878; Zhu et al., GCN 38885; Malesani et al., GCN 38902; Kumar et al., GCN 38907; Zhu et al, GCN 38908; Levan et al., GCN 38909; Izzo, GCN 38912; Zou et al., GCN 38914; Moskvitin & Spiridonova, GCN 38925; Song et al., GCN 38972; Eyles-Ferris et al., GCN 38983; Xu et al., GCN 38984) to EP250108a (Li et al., GCN 38861) with the GMOS spectrograph mounted on the Gemini-South telescope (PI: Rastinejad; program GS-2024B-Q-105). We obtained 4 x 400 s spectroscopy beginning at 2025-01-19 01:29 UT, approximately 10.5 days after the EP/WXT trigger. Spectroscopy was taken with the B480 grism, covering the spectral range from 4250-8500 AA. The optical counterpart is well detected across the spectral range. In contrast to earlier observations which showed a hot, blue continuum (Zhu et al., GCN 38908), it is now characterised by a redder shape. In addition, broad features are now visible in the spectrum with high signal to noise. Both the spectral shape and broad features resemble those found in broad-lined type Ic supernovae. Our findings find further support for the conclusions based on NOT spectroscopic observations (Xu et al., GCN 38394, and are also consistent with the optical re-brightening reported by Eyles-Ferris et al. (GCN 38983). On this basis we therefore conclude that the FXT and FBOT EP250108a is related to the core-collapse of a massive star. The earlier bright blue emission may be consistent with a rapidly cooling black body, similar to that seen in GRB/XRF 060218 (Campana et al. 2006, doi:10.1038/nature04892; Pian et al. 2006, doi:10.1038/nature05082), although it appears to last for a much longer period (days instead of hours) in the case of EP250108a. We thank the staff of Gemini, especially Murilo Marinello and Joanna Thomas-Osip for their excellent support in securing these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/38987. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36994] LIGO/Virgo/KAGRA S250119cv: Identification of a GW compact binary merger candidate
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38986 SUBJECT: LIGO/Virgo/KAGRA S250119cv: Identification of a GW compact binary merger candidate DATE: 25/01/19 19:28:51 GMT FROM: Julio Martins at National Institute for Space Research <julio.martins(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S250119cv during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2025-01-19 19:02:38.316 UTC (GPS time: 1421348576.316). The candidate was found by the CWB [1], CWB BBH [2], GstLAL [3], MBTA [4], PyCBC Live [5], and SPIIR [6] analysis pipelines. S250119cv is an event of interest because its false alarm rate, as estimated by the online analysis, is 4e-20 Hz, or about one in 1e12 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S250119cv The classification of the GW signal, in order of descending probability, is BBH (>99%), BNS (<1%), NSBH (<1%), or Terrestrial (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [7] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [7] 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 1%. 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 [8], distributed via GCN notice about 27 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [8], 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 well fit by an ellipse with an area of 18 deg2 described by the following DS9 region (right ascension, declination, semi-major axis, semi-minor axis, position angle of the semi-minor axis): icrs; ellipse(00h55m, +27d29m, 2.56d, 2.20d, 69.78d) Marginalized over the whole sky, the a posteriori luminosity distance estimate is 478 +/- 126 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] Klimenko et al. PRD 93, 042004 (2016) doi:10.1103/PhysRevD.93.042004 [2] T. Mishra et al. PRD 105, 083018 (2022) doi:10.1103/PhysRevD.105.083018 [3] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [4] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913 [5] Dal Canton et al. ApJ 923, 254 (2021) doi:10.3847/1538-4357/ac2f9a [6] Chu et al. PRD 105, 024023 (2022) doi:10.1103/PhysRevD.105.024023 [7] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe [8] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013 View this GCN Circular online at https://gcn.nasa.gov/circulars/38986. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36993] LIGO/Virgo/KAGRA S250119ag: Updated Sky localization
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38985 SUBJECT: LIGO/Virgo/KAGRA S250119ag: Updated Sky localization DATE: 25/01/19 17:30:22 GMT FROM: Patricia Schmidt at University of Birmingham <patricia.schmidt(a)ligo.org> 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 S250119ag (GCN Circular ***38978***). 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/S250119ag For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 538 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 3000 +/- 676 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/38985. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36992] EP250108a/AT 2025kg: NOT spectroscopy in agreement with SN Ic-BL
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38984 SUBJECT: EP250108a/AT 2025kg: NOT spectroscopy in agreement with SN Ic-BL DATE: 25/01/19 15:49:39 GMT FROM: Dong Xu at NAOC/CAS <dxu(a)nao.cas.cn> D. Xu, Z.P. Zhu, X. Liu (NAOC), J.P.U. Fynbo (DAWN/NBI), X.Z. Zou, B. Kumar, X.W. Liu (SWIFAR, YNU), F.F. Song, R.Z. Li, J.R. Mao (YNAO), Y.Q. Liu, T. An (SHAO), W.X. Li (NAOC), X.F. Wang (THU), J.J. Geng, X.F. Wu (PMO), H. Sun, W.M. Yuan (NAOC), B. Zhang (UNLV), report on behalf of a large collaboration: We have been doing multi-band photometry of the optical counterpart of EP250108a detected by EP (Li et al., GCN 38861) at different telescopes, including NOT, Mephisto, and GMG (e.g., Zhu et al., GCN 38885; Malesani et al., GCN 38902; Zou et al., GCN 38914; Song et al., GCN 38972). The g-/r-/i- band light curves show slow decay followed by slow re-brightening over the past days, in agreement with the report by Eyles-Ferris et al. (GCN 38983). We carried out spectroscopy of the counterpart in the night of Jan. 18, ~ 10 days post-trigger, using the the ALFOSC instrument mounted on the NOT. Observations consisted of 4 exposures of 1200 s each, and the spectra cover the wavelength range 3600 - 9000 AA. The target, including the counterpart and its host galaxy, has r ~ 20.2 mag (AB), while the host galaxy has r ~ 23.2 mag (AB) from Legacy Survey. Therefore the spectrum is certainly dominated by the counterpart itself. The spectral continuum doesn't have a high S/N, but the spectral shape is clearly present, due to its significant fluctuation. Using Superfit, we found the spectrum is in good agreement with the broad-lined Ic (Ic-BL) SN 1998bw associated with GRB 980425, the prototype of GRB/XRF-SN association events, about 6 days before its maximum, i.e., ~ 15 days post-burst. Further observations are planned. View this GCN Circular online at https://gcn.nasa.gov/circulars/38984. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36991] EP250108a / AT 2025kg: the kangaroo is hopping, evidence for optical rebrightening
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38983 SUBJECT: EP250108a / AT 2025kg: the kangaroo is hopping, evidence for optical rebrightening DATE: 25/01/19 13:30:18 GMT FROM: Rob Eyles-Ferris at U of Leicester <raje1(a)leicester.ac.uk> R. A. J. Eyles-Ferris (Leicester), D. B. Malesani (DAWN/NBI and Radboud), P. T. O’Brien (Leicester), P. G. Jonker (Radboud), A. J. Levan (Radboud and Warwick), J. N. D. van Dalen (Radboud), A. Kumar (RHUL/Warwick), B. Gompertz (Birmingham), N. R. Tanvir (Leicester), report on behalf of several collaborations: Following the discovery of the optical counterpart (“the kangaroo”; Eyles-Ferris, GCN 38878; Zhu et al., GCN 38885; Malesani et al., GCN 38902; Kumar et al., GCN 38907; Zhu et al, GCN 38908; Levan et al., GCN 38909; Izzo, GCN 38912; Zou et al., GCN 38914; Moskvitin & Spiridonova, GCN 38925; Song et al., GCN 38972) of the fast X-ray transient EP250108a (Li et al., GCN 38861), we started a monitoring campaign using the Liverpool Telescope and the Nordic Optical Telescope, both located on the island of La Palma, Spain. Observations were conducted in the griz filters. The transient has been evolving rather slowly - certainly much slower than typical GRB or FXT afterglows (host contamination is not an issue, as it is significantly fainter at r ~ 23.2). The spectral shape has shown an overall trend of transitioning from blue to red. Starting on about January 17, the r and i bands are seen to brighten, by about 0.3-0.4 mag in both the LT and NOT observations, also consistent with the report by Song et al. (GCN 38972). The most recent r-band magnitude is 20.30 +/- 0.07 (AB), measured in LT observations starting at 2025-01-18 20:17:45 UT (approximately 10.3 days post trigger). This rebrightening might be the indication of an emerging SN. We acknowledge excellent support from the observing staff at the NOT. View this GCN Circular online at https://gcn.nasa.gov/circulars/38983. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36990] GRB 250117A: GECAM observation of a short burst
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38982 SUBJECT: GRB 250117A: GECAM observation of a short burst DATE: 25/01/19 12:49:03 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> Chen-Wei Wang, Yan-Qiu Zhang, Jin-Peng Zhang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered in-flight by a short burst, GRB 250117A, at 2025-01-17T20:21:57.950 UTC (denoted as T0), which was also detected by Fermi/GBM, Konus-Wind and INTEGRAL/SPI-ACS. According to the GECAM-B light curves in about 20-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of about 0.70 +0.25/-0.65 s. The GECAM-B light curve can be found here: https://www.bursthub.cn//admin/static/gecamgrb250117A.png Using the automatic on-ground localization pipeline, GECAM-B localized this burst to the following position (J2000): Ra: 271.8 deg Dec: -23.2 deg Err: 7.6 deg (1-sigma, statistical only) We note that GRB 250117A is located near the galactic disc, and its localization seems to be consistent with the position of GRB 250116A (Ra= 266.64 deg，Dec=-19.36 deg, Err=0.13 deg, GCN # 38963) within the error, which may suggest that both bursts possibly come from ssan interesting galactic source. More analysis is ongoing. Follow-up observations of GRB 250117A and GRB 250116A are encouraged. Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two micro-satellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS). View this GCN Circular online at https://gcn.nasa.gov/circulars/38982. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36989] LIGO/Virgo/KAGRA S250118dp: Updated Sky localization
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38981 SUBJECT: LIGO/Virgo/KAGRA S250118dp: Updated Sky localization DATE: 25/01/19 09:41:37 GMT FROM: Soichiro Morisaki at U. of Tokyo <soichiro.morisaki(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further analysis of the LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) data around the time of the compact binary merger (CBC) candidate S250118dp (GCN Circular 38975). 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/S250118dp For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 798 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1916 +/- 465 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/38981. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36988] GRB 250119B: BALROG localization (Fermi Trigger 758968026 / GRB 250119352)
by GCN Circulars 19 Jan '25

19 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38980 SUBJECT: GRB 250119B: BALROG localization (Fermi Trigger 758968026 / GRB 250119352) DATE: 25/01/19 08:59:13 GMT FROM: Jochen Greiner at MPE <jcgrog(a)mpe.mpg.de> T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 758968026 at 08:27:01 on 19 Jan. 2025 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position is: RA(2000.0) = 306.3 deg Decl.(2000.0) = 19.3 deg The 1 sigma statistical error radius is 1.8 deg. We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB250119352/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB250119352/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB250119352/json View this GCN Circular online at https://gcn.nasa.gov/circulars/38980. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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