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[vsnet-grb-info 40661] Fermi Gamma-ray Burst Monitor trigger 784109140/251106337 is not a GRB
by GCN Circulars 06 Nov '25

06 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42598 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 784109140/251106337 is not a GRB DATE: 25/11/06 09:25:27 GMT FROM: Utkarsh Pathak at IIT Bombay <utkarshpathak.07(a)gmail.com> U. Pathak (IITB) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 784109140/251106337 at 08:05:35.06 UT on 06 November 2025, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to local particles." View this GCN Circular online at https://gcn.nasa.gov/circulars/42598. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40660] EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart
by GCN Circulars 06 Nov '25

06 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42597 SUBJECT: EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart DATE: 25/11/06 06:42:49 GMT FROM: Xinglong Observatory at National Astronomical Observatories (NAOC), Chinese Academy of Sciences (CAS) <xinglong(a)nao.cas.cn> Yu-Zhang(NAOC), Junjie-Jin(NAOC), Haiyang-Mu(NAOC), Junjun-Jia(NAOC), Jie-Zheng(NAOC), Yinan-Zhu(NAOC), Zhou-Fan(NAOC), Hong-Wu(NAOC) report on behalf of a large collaboration: We observed the field of the X-ray transient EP251102a, detected by EP/WXT, using the Xinglong 2.16-m telescope at Xinglong, Hebei, China. We obtained three 300 s clear-band frames with a median time of 2025-11-03T20:56:36, i.e. 9.2 hr after the EP trigger. The stacked clear-band image has a 5σ limiting magnitude of ≈23.0 mag, calibrated against Pan-STARRS g-band field stars. We detect the optical counterpart in the stacked image at RA (J2000) = 07:32:39.024 = 113.1626 deg Dec (J2000) = +07:19:18.88 = +7.32191 deg. This position is consistent with the candidate counterpart identified by Schneider et al. (GCN 42544). The preliminary magnitude of this source is 18.738 ± 0.025 (AB), which is brighter than reported in other follow-up observations (GCN 42544, 42546). We note the presence of a bright source ≈3 arcsec from the candidate counterpart, whose measured magnitude is consistent with its Pan-STARRS g-band magnitude, indicating that our flux calibration and PSF point-source decomposition are reliable. Therefore, the brightness of EP251102a in the clear band is likely intrinsically higher, or may be attributed to an unusual spectral energy distribution (SED) of the source. Further observations are encouraged. View this GCN Circular online at https://gcn.nasa.gov/circulars/42597. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40659] GRB 251105A: Fermi GBM Observation
by GCN Circulars 05 Nov '25

05 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42596 SUBJECT: GRB 251105A: Fermi GBM Observation DATE: 25/11/05 23:37:24 GMT FROM: oindabimukherjee(a)gmail.com O. Mukherjee (USRA) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 04:41:06.40 UT on 05 November 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251105A (trigger 784010471/251105195) which was also detected by Swift/BAT-GUANO (J. DeLaunay et al. 2025, GCN 42593). The Fermi GBM on-ground location is consistent with the Swift/BAT-GUANO position. The angle from the Fermi LAT boresight is 41 degrees. The GBM light curve consists of one emission episode with a duration (T90) of about 65 s (50-300 keV). The time-averaged spectrum from T0-23 to T0+87 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.13 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 220 +/- 30 keV. A Band function fits the spectrum equally well with Epeak= 190 +/- 30 keV, alpha = -1.08 +/- 0.08 and beta = -2.38 +/- 0.39. The event fluence (10-1000 keV) in this time interval is (1.26 +/- 0.07)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+8.8 s in the 10-1000 keV band is 3.2 +/- 0.2 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/42596. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40658] GRB 251103B: Fermi GBM observation
by GCN Circulars 05 Nov '25

05 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42582 SUBJECT: GRB 251103B: Fermi GBM observation DATE: 25/11/04 21:18:14 GMT FROM: atrigg2(a)lsu.edu A. C. Trigg (NPP, NASA MSFC) report on behalf of the Fermi GBM Team: "At 16:46:36.44 UT on 03 November 2025, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 251103B (trigger 783881201/251103699), which was also detected by the Swift/XRT (Evans et al. 2025, GCN 42557) The Fermi GBM Final Real-time Localization (GCN 42555) is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 70 degrees. The GBM light curve shows/consists of rapid multi-peaked emission with a duration (T90) of about 48 s (50-300 keV). The time-averaged spectrum from T0-16.1 s to T0+39.8 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.36 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 82 +/- 2 keV. The event fluence (10-1000 keV) in this time interval is (4.67 +/- 0.12)E-6 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.98 s in the 10-1000 keV band is 5 +/- 0.3 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/42582. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40657] GRB 251105C: Fermi GBM Final Localization Correction
by GCN Circulars 05 Nov '25

05 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42595 SUBJECT: GRB 251105C: Fermi GBM Final Localization Correction DATE: 25/11/05 21:49:53 GMT FROM: Angus Jameson <abj0023(a)uah.edu> The Fermi GBM team reports the detection of a likely LONG GRB "At 18:45:56.05 UT on 05 November 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251105C (trigger 784061161/251105782). This trigger was initially classified as Below horizon by the flight software, but is in fact a GRB. The on-ground calculated location, using the Fermi GBM trigger data, is RA = 212.18, Dec = 37.29 (J2000 degrees, equivalent to J2000 14h 8m, +37d 17'), with a statistical uncertainty of 11.28 degrees. The angle from the Fermi LAT boresight is 68 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/42595. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40656] GRB 251105C: Fermi GBM Final Localization Correction
by GCN Circulars 05 Nov '25

05 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42595 SUBJECT: GRB 251105C: Fermi GBM Final Localization Correction DATE: 25/11/05 21:49:53 GMT FROM: Angus Jameson <abj0023(a)uah.edu> The Fermi GBM team reports the detection of a likely LONG GRB "At 18:45:56.05 UT on 05 November 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251105C (trigger 784061161/251105782). This trigger was initially classified as Below horizon by the flight software, but is in fact a GRB. The on-ground calculated location, using the Fermi GBM trigger data, is RA = 212.18, Dec = 37.29 (J2000 degrees, equivalent to J2000 14h 8m, +37d 17'), with a statistical uncertainty of 11.28 degrees. The angle from the Fermi LAT boresight is 68 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/42595. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40655] GRB 251105C: Fermi GBM Final Localization Correction
by GCN Circulars 05 Nov '25

05 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42595 SUBJECT: GRB 251105C: Fermi GBM Final Localization Correction DATE: 25/11/05 21:49:53 GMT FROM: Angus Jameson <abj0023(a)uah.edu> The Fermi GBM team reports the detection of a likely LONG GRB "At 18:45:56.05 UT on 05 November 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251105C (trigger 784061161/251105782). This trigger was initially classified as Below horizon by the flight software, but is in fact a GRB. The on-ground calculated location, using the Fermi GBM trigger data, is RA = 212.18, Dec = 37.29 (J2000 degrees, equivalent to J2000 14h 8m, +37d 17'), with a statistical uncertainty of 11.28 degrees. The angle from the Fermi LAT boresight is 68 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251105782/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/42595. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40654] LIGO/Virgo/KAGRA S251031dw: Candidates from the Zwicky Transient Facility
by GCN Circulars 05 Nov '25

05 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42594 SUBJECT: LIGO/Virgo/KAGRA S251031dw: Candidates from the Zwicky Transient Facility DATE: 25/11/05 19:02:41 GMT FROM: Shreya Anand <shreyasahasram08(a)gmail.com> Shreya Anand (Stanford), Anirudh Salgundi (UNC), Robert Stein (UMD), Vishwajeet Swain (IIT-B), Yogesh Wagh (IIT-B), Xander J. Hall (CMU), Mansi Kasliwal (Caltech), Eric Bellm (UW), Michael Coughlin (UMN), Theophile Jegou du Laz (Caltech), and Antonella Palmese (CMU) report, On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We observed the localization region of the LVK low-significance burst trigger S251031dw with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). We started observations in the g- and r-band beginning at 2025-11-01 12:22 UTC, approximately 15.2 hours after merger. We covered 23.1% of the reported localization region on 2025-10-31 and 60.9% of the localization on 2025-11-01. This estimate accounts for chip gaps. ~30% of the tiled localization was at a low galactic latitude. Each exposure was 200s with a median r-band depth of 21.1 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019, Stein et al. 2021) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019), removing candidates with history of variability prior to the merger time. After filtering, 58 transient candidates remain, all within the 95.0% localization of the skymap. None of these candidates have fast evolution consistent with kilonovae. We perform additional vetting of these candidates, and highlight 9 candidates that appear to be young and SN-like, or AGN-like, as candidates of interest in the burst search, in the table below: | ZTF Name | IAU Name | RA (deg) | DEC (deg) | MJD | Filt | Mag | MagErr | Note | | ------------ | ---------- | ---------- | ---------- | -------- | ---- | ----- | ------ | -------- | | ZTF25acchitl | -- | 127.996770 | -27.778576 | 60980.52 | r | 20.63 | 0.11 | AGN-like | | ZTF25accnabz | -- | 128.305827 | -23.858020 | 60980.52 | r | 21.60 | 0.19 | AGN-like | | ZTF25acchdbq | -- | 121.061164 | -19.087422 | 60980.50 | r | 20.35 | 0.21 | AGN-like | | ZTF25acchjjz | -- | 127.829510 | -20.792424 | 60980.52 | r | 20.88 | 0.12 | AGN-like | | ZTF25acchljm | -- | 130.363870 | -23.822309 | 60980.52 | r | 20.87 | 0.13 | AGN-like | | ZTF25accniqx | -- | 131.262056 | -20.691176 | 60980.54 | r | 20.16 | 0.15 | AGN-like | | ZTF25acchigq | -- | 128.491126 | -24.746190 | 60980.52 | r | 21.26 | 0.15 | AGN-like | | ZTF25acchszc | AT2025acno | 137.799671 | -22.017226 | 60980.54 | r | 20.93 | 0.13 | SN-like | | ZTF25acchppz | AT2025acep | 135.228502 | -23.983061 | 60980.54 | r | 19.48 | 0.05 | SN-like | ZTF25acchszc appears to be a rising young, blue supernova in a host galaxy (no redshift available). ZTF25acchppz is offset 9" from a potential host galaxy at z=0.082, and is therefore unlikely to be associated with the burst source. Further follow-up is encouraged. Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Award #2407588 and a partnership including Caltech, USA; Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; University of Wisconsin at Milwaukee, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan; Operations are conducted by Caltech's Optical Observatory (COO) and Caltech/IPAC. GROWTH acknowledges the generous support of the NSF under PIRE Grant No 1545949. Alert database searches are done by AMPEL (Nordin et al. 2019) and Kowalski (Duev et al. 2019). The GROWTH India Telescope (GIT, Kumar et al., 2022) is set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. Its operations are partially supported by funding from the IIT Bombay alumni batch of 1994. The Fritz and SkyPortal projects acknowledge the generous support of The Gordon and Betty Moore Foundation. View this GCN Circular online at https://gcn.nasa.gov/circulars/42594. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40653] LIGO/Virgo/KAGRA S251031dw: Candidates from the Zwicky Transient Facility
by GCN Circulars 05 Nov '25

05 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42594 SUBJECT: LIGO/Virgo/KAGRA S251031dw: Candidates from the Zwicky Transient Facility DATE: 25/11/05 19:02:41 GMT FROM: Shreya Anand <shreyasahasram08(a)gmail.com> Shreya Anand (Stanford), Anirudh Salgundi (UNC), Robert Stein (UMD), Vishwajeet Swain (IIT-B), Yogesh Wagh (IIT-B), Xander J. Hall (CMU), Mansi Kasliwal (Caltech), Eric Bellm (UW), Michael Coughlin (UMN), Theophile Jegou du Laz (Caltech), and Antonella Palmese (CMU) report, On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We observed the localization region of the LVK low-significance burst trigger S251031dw with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). We started observations in the g- and r-band beginning at 2025-11-01 12:22 UTC, approximately 15.2 hours after merger. We covered 23.1% of the reported localization region on 2025-10-31 and 60.9% of the localization on 2025-11-01. This estimate accounts for chip gaps. ~30% of the tiled localization was at a low galactic latitude. Each exposure was 200s with a median r-band depth of 21.1 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019, Stein et al. 2021) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019), removing candidates with history of variability prior to the merger time. After filtering, 58 transient candidates remain, all within the 95.0% localization of the skymap. None of these candidates have fast evolution consistent with kilonovae. We perform additional vetting of these candidates, and highlight 9 candidates that appear to be young and SN-like, or AGN-like, as candidates of interest in the burst search, in the table below: | ZTF Name | IAU Name | RA (deg) | DEC (deg) | MJD | Filt | Mag | MagErr | Note | | ------------ | ---------- | ---------- | ---------- | -------- | ---- | ----- | ------ | -------- | | ZTF25acchitl | -- | 127.996770 | -27.778576 | 60980.52 | r | 20.63 | 0.11 | AGN-like | | ZTF25accnabz | -- | 128.305827 | -23.858020 | 60980.52 | r | 21.60 | 0.19 | AGN-like | | ZTF25acchdbq | -- | 121.061164 | -19.087422 | 60980.50 | r | 20.35 | 0.21 | AGN-like | | ZTF25acchjjz | -- | 127.829510 | -20.792424 | 60980.52 | r | 20.88 | 0.12 | AGN-like | | ZTF25acchljm | -- | 130.363870 | -23.822309 | 60980.52 | r | 20.87 | 0.13 | AGN-like | | ZTF25accniqx | -- | 131.262056 | -20.691176 | 60980.54 | r | 20.16 | 0.15 | AGN-like | | ZTF25acchigq | -- | 128.491126 | -24.746190 | 60980.52 | r | 21.26 | 0.15 | AGN-like | | ZTF25acchszc | AT2025acno | 137.799671 | -22.017226 | 60980.54 | r | 20.93 | 0.13 | SN-like | | ZTF25acchppz | AT2025acep | 135.228502 | -23.983061 | 60980.54 | r | 19.48 | 0.05 | SN-like | ZTF25acchszc appears to be a rising young, blue supernova in a host galaxy (no redshift available). ZTF25acchppz is offset 9" from a potential host galaxy at z=0.082, and is therefore unlikely to be associated with the burst source. Further follow-up is encouraged. Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Award #2407588 and a partnership including Caltech, USA; Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; University of Wisconsin at Milwaukee, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan; Operations are conducted by Caltech's Optical Observatory (COO) and Caltech/IPAC. GROWTH acknowledges the generous support of the NSF under PIRE Grant No 1545949. Alert database searches are done by AMPEL (Nordin et al. 2019) and Kowalski (Duev et al. 2019). The GROWTH India Telescope (GIT, Kumar et al., 2022) is set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. Its operations are partially supported by funding from the IIT Bombay alumni batch of 1994. The Fritz and SkyPortal projects acknowledge the generous support of The Gordon and Betty Moore Foundation. View this GCN Circular online at https://gcn.nasa.gov/circulars/42594. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40652] GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
by GCN Circulars 05 Nov '25

05 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42593 SUBJECT: GRB 251105A: Swift/BAT-GUANO localization skymap of a burst DATE: 25/11/05 18:16:19 GMT FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com> James DeLaunay (PSU), Samuele Ronchini (GSSI), Aaron Tohuvavohu (Cosmic Frontier), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC), Maia Williams (Northwestern) report: Swift/BAT did not localize GRB 251105A onboard (T0: 2025-11-05T04:41:06.40 UTC, Fermi Trig 784010471) 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 22.9 in a 16.384 s analysis time bin, starting at T0 + 4.096 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 747 deg2 and the 50% credible area is 279 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 (GCN 42584). The combined Fermi/GBM+NITRATES 90% credible area is 129 deg2 and the 50% credible area is 35 deg2. A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=784010503/#:~:te… The probability skymap and joint skymap files can be downloaded from the links here [skymap_fits_file](https://guano.swift.psu.edu/files/784010503/0_n_PROBMAP) [joint_skymap_fits_file](https://guano.swift.psu.edu/files/784010503/0_n_JOI… 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=784010503 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/42593. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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