Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 29053

VLA observations of GW170817 at ~3.3 years post-merger
2020-12-16T01:40:37Z (3 years ago)
Kate Alexander at Northwestern U <>
K. D. Alexander, A. Hajela, R. Margutti, J. Bright (Northwestern U.), T.
Eftekhari (Harvard U.), A. Kathirgamaraju (UC Berkeley), and E. Berger
(Harvard U.) report on behalf of a larger collaboration:

We observed GW170817 with the NSF���s Karl G. Jansky Very Large Array (the
VLA) at t =1216 days (~3.3 years) after the binary neutron star merger
(joint program SL0449, PI: Margutti). In our preliminary analysis, no radio
emission is detected at the location of GW170817; we infer a 3-sigma upper
limit of ~13 microJy at a central frequency of 3 GHz. Assuming the X-ray
flux density recently reported by Hajela et al. (GCN 29041) and a simple
power-law spectrum, this is fully consistent with the F_nu ~ nu^-0.575
spectrum observed throughout GW170817���s earlier evolution (e.g. Hajela et
al. 2019).

We thank the VLA staff for scheduling and executing these observations.
Looking for U.S. government information and services? Visit