  We cross-match the GALEX and Kepler surveys to create a unique dataset with
both ultraviolet (UV) measurements and highly precise photometric variability
measurements in the visible light spectrum. As stellar activity is driven by
magnetic field modulations, we have used UV emission from the magnetically
heated gas in the stellar atmosphere to serve as our proxy for the more
well-known stellar activity indicator, R'HK. The R'HK approximations were in
turn used to estimate the level of astrophysical noise expected in radial
velocity (RV) measurements and these were then searched for correlations with
photometric variability. We find significant scatter in our attempts to
estimate RV noise for magnetically active stars, which we attribute to
variations in the phase and strength of the stellar magnetic cycle that drives
the activity of these targets. However, for stars we deem to be magnetically
quiet, we do find a clear correlation between photometric variability and
estimated levels of RV noise (with variability up to ~ 10 m/s). We conclude,
that for these quiet stars, we can use photometric measurements as a proxy to
estimate the RV noise expected. As a result, the procedure outlined in this
paper may help select targets best-suited for RV follow-up necessary for planet
confirmation.
