Preliminary Characteristics of Kepler Long Cadence Data For Detection of Transiting Planets
Abstract
We present results from the first 45 days of science data collected with the Kepler Photometer in May and June 2009. In general, the photometric precision for main sequence stars lies close to expectations based on the standard propagation of uncertainties. The bulk of these stars are within a factor of approximately 1.5 of the desired photometric precision required to detect Earth-sized planets transiting Sun-like stars. There is a strong separation between quietest giant stars’ photometric variability and that of quiet main-sequence stars. Most of the giant stars exhibit variability above 100 ppm on timescales of ½ hour (one Long Cadence). The photometric precision obtained to date is controlled by our ability to identify and remove instrumental systematic signatures due to such sources as pointing excursions and small changes in focus. The detection of transit-like features in the light curves has been complicated by the presence of some instrumental and systematic effects, but we have been able to identify and correct these sources to a level at which we can detect signatures of super-Earth and larger planets. We are able to discard false positives due to background eclipsing binaries in many cases by direct inspection of Kepler data. Kepler targets flagged by our Transiting Planet Search component are examined for correlation between shifts in their photocenters (centroids) and the detected photometric transit-like signature. Difference images have also been produced for these targets by subtracting the average of in-transit frames from out-of-transit frames, often exposing the location of the background eclipsing binary directly. These tools have proven to be invaluable in identifying cases where a target star is contaminated by a background eclipsing binary that is the source of the transit-like features.
Funding for this mission is provided by NASA's Discovery Program Office, SMD.- Publication:
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American Astronomical Society Meeting Abstracts #215
- Pub Date:
- January 2010
- Bibcode:
- 2010AAS...21530503J