Talk abstract details

VARLET and PHALET two wavelet based filter methods to separate stellar variation, orbital disturbances and instrumental effects from transit events in CoRoT light curves.
Grziwa, Sascha; Korth, Judith; Pätzold, Martin


Various stellar variations (star spots, pulsation, flares…) may mask faint planetary transit in stellar light curves. Periodic spacecraft orbital and non-periodic instrumental effects (glitches, hot pixels...) disturb detection algorithms and lead to false positive detections. The huge number of stellar light curves can only be handled by fully automated filtering and detection algorithms. The modeling of all potential effects for proper light curve correction is impossible.
The Rheinisches Institut für Umweltforschung (RIU-PF) at Cologne University is one of the CoRoT detection teams and has developed wavelet based filter methods to improve the detection pipeline.
We present two model independent wavelet based filter techniques VARLET and PHALET.
VARLET separates faint transit signals from stellar variations without using a-priori information of the target star. Stellar variations are distinguished by frequency, amplitude and shape. VARLET extracts also most instrument generated jumps and glitches.
PHALET is used to separate features with well known period in the light curve like diluting binaries and periodic spacecraft orbital effects. It is also used for the multi-transit-search. The combination of both filter techniques improves the detection limit substantially, reduces the number of false positive detection and simplifies the detection of faint transits in CoRoT light curves.

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