Expected effects of hot CCD pixels on detection of transits of extra-solar planets with the Kepler Mission

摘要

Detection of Earth sized extra-solar planets by the transit method requires measurement of quite small variations (～ 8 x 10~(-5)) in the brightness of candidate stars. Noise contributed by hot pixels in CCD detectors operating in the space environment, among other noise sources, must be understood and controlled in order to design transit experiments like the Kepler Mission, which will attempt to measure the distribution of planets as small as the Earth around solar type stars from space. We have analyzed the hot pixel statistics for CCD detectors on several operating space instruments and conclude that neither the amplitude nor the variability of hot pixels will significantly impair the ability of the Kepler Mission to detect transits of earth sized planets transiting solar type stars. The Kepler Mission is currently in the design stage and is expected to begin operation in 2007.