Oversampling mode Roi Alonso, Pierre-Yves Chabaud Christian Surace, Raphael Cautain, P. Barge

Planned procedures Inputs –N1 data from the LESIA pipeline –Scientific criteria –Additional programs Specific algorithms in various steps Output –List of targets (XML files)  SEF/CMC

The various steps 1)Preprocessing of the data –To filter residuals of the SAA and orbital perturbations –To remove disturbing low frequencies of Stellar Variability (moving box, Fourier & wavelets, … multiplex-PCA) 2)Detection of possible transits –Two complementary algorithms running in parallel MID (Morphological Detector) + EPF (Periodicity Finder) BLS (Box fitting Least Square) –Estimate of a confidence level for each detected event 3)Discrimination/priority –Building a common list of detected events –Use simple tools to remove ambiguities (SOS) 4)Management of the lists –EXOP/AP

Filtered LCs MIDBLSMID+EPF List with P and E of best detections List with P and E of best detections List with Epoch of best detections Merging of the detection lists Input for the discrimination tools Trapezoidal fitting of the phase-folded LC Period P and Epoch E Single list of outputs Sorting - no repetitions

Priority: removing ambiguites To discriminate planetary transits from: Eclipsing Binaries, variable stars, false detections (noisy features) Identification of EB ligth curve –Search for secondary transits in the signal folded at 1xPeriod around epoch –Looking at differences (depth & position) between even and odd eclipses in the signal folded at 2xPeriod around epoch Search for out of eclipse modulations (peak in the spectrum) Use of colours (trapezoidal fitting in each channel)  Reduced list of candidates (sorted by increasing order of the sum of 4 significances)  Exoplanet candidates for oversampling (ordered in priority after visual inspection - SOS)

Exo - Transit Detection Tools: Discrimination/Priority Exo - Candidate list (core) Exo - Initial list (core) AP-targets list Exo-CCD list Combine lists Exo-CCD - XML file Exo - Detection list EXODAT AP - Variability analysis Exo - Sorted list Visual Inspection - SOS

How things are presently working Inputs –Raw N0 data instead of N1 (N1 only available since ~ 1 month) Raw data are put in the N1 format Algorithms –Automated procedures not at work –LC analysis made using visual inspection Management of the oversampling lists –Variability analysis by the AP at work Output –List of targets (XML files)  SEF/CMC (OK)

Results from the alarm mode Two alarm candidates during IRa01 –One confirmed planet No alarm candidates during SRc01 (no available data) 19 alarm candidates during LRc01 Intense Follow Up effort during the summer –2 confirmed planets –~ 5 eclipsing binaries –FU observations are still going on Only the most obvious candidates were detected The alarm pipeline must be improved !

Information released for FU operations The lists of « alarms » are accessible to the Science Team only for the purpose of Follow Up operations (periods, depths and durations of the events + the contaminating background stars) The coordinates of the targets are accessible only to the members of the FU coordination group (leaders of the FU working groups + some experts)

Encountered difficulties Due to the production of the N1 data –Long delay in the data delivery (up to 1 month) –Some gaps introduced in the N1 products –Non homogeneous level of the corrections Pipeline corrections introduced in the data: –Reversed or negative « hot » pixels –Some additional discontinuities Hot pixels: –Detection and modeling (L. Jorda & R. Cautain) -> corrections –Filtering using wavelet transform (R. Alonso)

Incomplete corrections and “mirroring” of hot pixels N0 N1

Discontinuities introduced in the N1 data N0 N1 ?

Necessary evolution  To be effective the alarm software needs: –Regular delivery of data all along the run –Data corrected in an homogenous way (continuity of the corrections) A possibility is to produce data specifically processed for the alarm mode (only simple corrections performed on the raw data in a regular and continuous way) This possibility is under study