Effect of realistic and filtered stellar photometric noise on the detection of moons using photometric transit timing

Abstract

The photometric transit timing technique was proposed by Szabó et al. (2006) as a method for discovering moons of transiting extrasolar planets. In the preliminary analysis of this technique, it was assumed that the noise in the transit lightcurve was well described by uncorrelated white noise. However, this assumption is not necessarily realistic. To determine the effect of using more realistic lightcurves, transit timing uncertainties are calculated for the case of white noise, measured solar photometric noise and measured solar photometric noise that has been filtered. It is found that for light curves contaminated with realistic photometric noise, the transit timing uncertainties are dramatically increased (and thus moon detection reduced). In addition, we find that while filtering reduced this problem, it did not negate it.