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Paper: The Frequency Content of the VIRGO/SoHO Light Curves: Implications for Planetary Transit Detection from Space
Volume: 294, Scientific Frontiers in Research on Extrasolar Planets
Page: 441
Authors: Aigrain, S.; Gilmore, G.; Favata, F.; Carpano, S.
Abstract: Stellar micro-variability poses a serious threat to the capacities of space-based planet-finding missions such as Kepler or Eddington. The solar light curves obtained by the VIRGO PMO6 and SPM instruments on board SoHO from 1996 to 2001 have been studied in order to follow variability changes through the activity cycle. In all datasets, active region induced variability, below 2 micro-Hz, is closely correlated to the BBSO Ca II K-line index. The PMO6 (total irradiance) data show evidence for a meso-granulation component with time scale about 8000 seconds, while all narrow-band SPM datasets (red, green and blue) show super-granulation (time scale 50,000 seconds) but no meso-granulation. Both actvity and granulation related components have significantly smaller amplitudes in the red than in the blue channel. These results, coupled with available stellar data, allow us to generate simulated light curves with enhanced variability as a testbed for pre-processing and detection methods, and influence the case for using colour information in this kind of mission.
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