A Refined Model of Convectively Driven Flicker in Kepler Light Curves

Light curves produced by the Kepler mission demonstrate stochastic brightness fluctuations (or "flicker") of stellar origin which contribute to noise floor, limiting sensitivity exoplanet detection and characterization methods. In stars with surface convection, primary driver these variations on short (sub-eight-hour) timescales is believed be convective granulation. this work, we improve existing models granular flicker amplitude, or $F_8$, including effect bandpass measured flicker, incorporating metallicity in determining Mach numbers, using scaling relations from a wider set numerical simulations. To motivate validate changes, use recent database measurements stars, allows us more fully detail remaining model--prediction error. Our model improvements reduce typical misprediction amplitude factor 2.5 2. We rule out rotation period strong magnetic activity as possible explanations for error, show that binary companions may affect flicker. also introduce an "envelope" predicts range amplitudes any one star account some spread simulations, find covers 78% observed stars. note solar lower than most Sun-like This improved can better characterize source studies well inform simulations