TITLE:   GCN CIRCULAR
NUMBER:  25622
SUBJECT: LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh
DATE:    19/09/03 05:05:39 GMT
FROM:    J. Craig Wheeler at U.Texas Austin  <wheel@astro.as.utexas.edu>

M. J. B. Rosell, Karl Gebhardt, Aaron Zimmerman, Matthew Shetrone, Chris Fryer, J. Craig Wheeler, Steve Odewahn, and Nathan McReynolds on behalf of the LIGO Hobby-Eberly Telescope Response (LIGHETR) team, report the spectroscopic observation of the candidate optical transient ZTF19abvionh(GCN #25616) in the field of S190901ap (GCN #24208). The observations cover the wavelength range of 3500 to 5500 Angstroms. We detect a nearly featureless continuum peaking at about 4500 Angstroms. There are emission lines at about 4124 Angstroms and 5370 Angstroms that probably correspond to [O II] 3727 and Hbeta at a redshift of ~0.1. These emission lines are likely to be associated with nearby galaxy GALEXASC J165500.03+140301.3. The image of the target object falls within the extent of this galaxy. The distance corresponding to this redshift is 450 Mpc, about 2.5 sigma more than the estimated distance of the merger candidate.