Tests for time series analysis on exodata


Test cases on exofield

The COROT space telescope will work with four CCDs. Two of them are used for the astroseismo targets (seismo fields). The other two CCDs are used for planetary transit search (exofields).

On the seismo fields small windows around the main targets and nine secondary targets will be telemetried. The smaller boxes allow us to use 32 seconds as sampling frequency which is ideal to measure short period variability.

On the exofields, however, the whole CCD frames will be telemetried. Because of the finite telemetric capacity, the exofields will be sampled once in each 8 minutes. This sampling frequency is enough for planetary transit search. The present test cases check whether the 8 minutes sampling time is proper for seismological investigation of pulsating stars located on the exofields. RR Lyrae, Cepheids and Delta Scuti stars have been involved in the test cases. Special attention was payed to the critical frequency separation in the long period variable stars and the multimode pulsation of low amplitude Delta Scuti stars.

Synthetic data

Synthetic data sets were generated over 150 days, the duration of the long COROT run. Points were generated in every 8 minutes as in the real datasets coming down on the stars in the exofields. 27000 points were obtained. No noise were added to the sine waves.

The capacity of the MUFRAN period analysing software package gives the possibility to analyse a limiting frequency range as 6.83 c/d.