TITLE: GCN CIRCULAR NUMBER: 27287 SUBJECT: LIGO/Virgo S200302c: No counterpart candidates in HAWC observations DATE: 20/03/02 15:39:53 GMT FROM: Israel Martinez-Castellanos at UMD/HAWC The HAWC Collaboration (https://www.hawc-observatory.org) reports: The HAWC Collaboration performed a follow-up of the gravitational wave trigger S200302c (GCN #27278). At the time of the trigger the HAWC local zenith was oriented towards (RA, Dec) = (92.3 deg, 19.0 deg). 31% of the GW candidate sky location probability fell within our observable field of view (0-45 deg zenith angle). We performed a search for a short timescale emission using 6 sliding time windows (dt = 0.3s, 1s, 3s, 10s, 30s and 100s), shifted forward in time by 20% of their width. We searched the 95% probability containment area in a timescale-dependent time period, from t0-5dt to t0+10dt, where t0 is the time of the GW trigger. No significant gamma-ray detection above the background was observed. The sensitivity of this analysis is greatly dependent on zenith angle, ranging from 0 deg to 45 deg for the area searched in this analysis. The 5sigma detection sensitivity to a 1s (100s) burst in the 80-800GeV energy range goes from 1.2e-6 erg/cm^2 to 1.1e-4 erg/cm^2 (6.4e-6 erg/cm^2 to 5.0e-4 erg/cm^2), depending on the zenith angle. HAWC is a TeV gamma ray water Cherenkov array located in the state of Puebla, Mexico. It is sensitive to the energy range ~0.1-100TeV, and monitors 2/3 of the sky every day with an instantaneous field-of-view of ~2 sr.