GCN Circular 44229
Subject
EP260321a: Upper limits from VLA radio observations
Event
Date
2026-04-07T14:50:36Z (21 hours ago)
From
James Leung at U. Toronto / HUJI <jamesk.leung@utoronto.ca>
Via
Web form
J. K. Leung (U. Toronto/HUJI), L. Izzo (INAF-OACN), F. de Colle (UNAM), and M. R. Drout (U. Toronto) report on behalf of a larger collaboration:
We report radio observations of EP260321a (Huang et al., GCN 44068) conducted on the Karl G. Jansky Very Large Array (VLA). The observations were centred at the position of the putative optical counterpart (Lee et al., GCN 44070; Tanvir et al., GCN 44082; Moran et al., GCN 44083, Ahumada et al., GCN 44084, Liu et al., GCN 44087, de Ugarte Postigo et al., GCN 44091, Pankov et al. GCN 44103, Gao et al., GCN 44110, He et al., GCN 44117, Zhang et al., GCN44171), identified now as the broad-lined type-Ic supernova SN 2026gzf (Corcoran et al., GCN 44105, Rastinejad et al., GCN 44107).
The radio observations were taken from UT05:12-07:42 on 2026-03-27 (~5.7 days post-trigger) at the central observing frequencies of 6, 10, 15 and 22 GHz. In our preliminary analysis, we detect no radio source at the position of the putative optical counterpart to EP260321a, giving a 3-sigma non-detection limit of <0.03 mJy/beam at each observing frequency band.
We thank the VLA and NRAO staff for quickly scheduling and executing these observations. Further observations are planned.
The National Radio Astronomy Observatory and Green Bank Observatory are facilities of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.