TITLE: GCN CIRCULAR NUMBER: 38034 SUBJECT: EP241021a: Upper limit from Konus-Wind observations DATE: 24/11/01 13:52:02 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru> D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: Konus-Wind (KW) was observing the whole sky at the time of the detection of a fast X-ray transient EP241021a (2024-10-21 05:07:56 UTC, hereafter T0; Hu et al., GCN 37834). Using waiting-mode data within the interval T0 +/- 1000 s, we found no significant (> 5 sigma) excess over the background in S1 KW detector, with smallest incident angle, on temporal scales from 2.944 s to 1000 s. We estimate an upper limit (90% conf.) on the 20 - 1500 keV peak flux to 2.5x10^-7 erg/cm^2/s for a typical long GRB spectrum (the Band function with alpha=-1, beta=-2.5, and Ep=300 keV) and 2.944 s timescale. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/38034. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...