The Stability of F-star Brightness on Century Timescales
  The century-long photometric record of the DASCH project provides a unique window into the variability of stars normally considered to be photometrically inactive. In this paper, we look for long-term trends in the brightness of F stars, with particular attention to KIC 8462852,an F3 main sequence star that has been identified as significant short-term variability according to Kepler observations. Although a simple search for variability suggests long-term dimming of a number of F stars, we find that such trends are artifacts of the 'Menzel Gap' in the DASCH data. That includes the behavior of KIC 8462852, which we believe is consistent with constant flux over the full duration of observations. We do, however, present a selection of F stars that do have significant photometric trends, even after systematics are taken into account. 
Michael B. Lund, Joshua Pepper, Keivan G. Stassun, Michael Hippke,   Daniel Angerhausen
astro-ph.SR astro-ph.EP