GCN Circular 24275
K. De (Caltech), L. Yan (Caltech), C. Fremling (Caltech), I. Andreoni (Caltech), D. Goldstein (Caltech) report on behalf of the ZTF and GROWTH collaborations We report on Target of Opportunity follow-up imaging and spectroscopy of the red transient DG19vkgf found in DECam imaging (Goldstein et al., GCN #24257; Andreoni et al., GCN #24268) of the localization region of S190426c (LIGO Scientific Collaboration and the Virgo Collaboration, GCN #24237). Spectra were obtained using the Double Beam Spectrograph (DBSP; Oke & Gunn 1982) on the Hale 200-inch telescope (P200) at Palomar observatory. We also obtained follow-up imaging of the source with the Wafer Scale Imager for Prime (WASP) on P200. Due to the high airmass of the observation and poor seeing, the transient is not clearly identified in the trace, but we confirm a host redshift of z = 0.04 from the host emission lines. However, the source is clearly detected in the images taken in i-band with WASP. We thank the staff of the Palomar observatory for facilitating these observations.