TITLE: GCN CIRCULAR NUMBER: 36495 SUBJECT: LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits DATE: 24/05/16 11:33:35 GMT FROM: GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn> Chenyu Wang, Zirui Yang and Longhao Li report on behalf of the GRID Collaboration: We have carried out a search for GRB candidates in GRID data in a 50 sec window around the trigger time of the event S240422ed (UTC 2024-04-22 21:35:13, GraceDB event). We do not find any evidence for any GRB transient in this window, in the GRID energy range of 10-1000 keV. At the time of the merger, GRID-04's nominal pointing is RA,DEC = 353.93, -48.06, which is ~94 deg away from the maximum probability location. We set the following 3 sigma flux upper limits over 10-1000 keV, weighted by GW localization probability (in units of 10^-7 erg/s/cm^2): GRID-04: Timescale Upper limit ----------------------------------------- 0.128 s: 6.2 1.024 s: 2.7 8.192 s: 1.3 GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4. View this GCN Circular online at https://gcn.nasa.gov/circulars/36495. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...