We present results from a deep VERITAS exposure of the distant (z=0.89) flat-spectrum radio quasar (FSRQ) 4C +55.17. The high flux, hard index and steady emission found by Fermi LAT observations make this blazar a promising VHE candidate, offering the possibility to clarify the location of FSRQ VHE emission. Non-detection supports the hypothesis that any VHE gamma-rays are produced within and absorbed by the broad-line region while VHE detection would support an emission region outside the broad-line region and far from the base of the jet.
This FSRQ additionally provides the possible means to constrain the currently available extragalactic background light (EBL) models out to the groundbreaking redshift of z=0.89. The log-parabolic model that is fitted to the LAT photons allows an extrapolation of the fit up to VHE while accounting for the gamma-ray absorption by the EBL. The VERITAS upper limit derived from the deep exposure is compared to this extrapolated VHE flux.