GCN Circular 41792
Subject
LIGO/Virgo/KAGRA S250908y: Updated Sky localization
Date
2025-09-11T11:27:49Z (a day ago)
From
natalie.williams@uni-potsdam.de
Via
Web form
The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:
We have conducted further analysis of the LIGO Hanford Observatory (H1) and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S250908y (GCN Circular 41750). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.multiorder.fits,0, distributed via GCN and SCiMMA notices, is available for retrieval from the GraceDB event page:
https://gracedb.ligo.org/superevents/S250908y
For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 9926 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1146 +/- 334 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. PRD 108, 123040 (2023) doi:10.1103/PhysRevD.108.123040