Vetting Kepler Planet Candidates with Multi-Color Photometry from the Gran Telescopio Canarias
Abstract
We present multi-color observations of small (super-Earth to Neptune-size) planet candidates recently identified by the Kepler space mission. By applying the unique capabilities of OSIRIS (installed on the 10.4-meter Gran Telescopio Canarias) for near-simultaneous multi-color photometry, we use the color of Kepler candidates as measured during predicted transit events to reject candidates that are false positives (e.g., a blend with an eclipsing binary in the background or bound to the target star). Our results include the discovery of a background eclipsing binary star (KIC 7025851) near KOI-565 (KIC 7025846). Based on the location of the eclipsing binary ( 15 arcsec from KOI-565), we conclude that the eclipsing binary contaminated the light from KOI-565 to mimic the super-Earth-size transit signal that was detected by Kepler. We also compare the technique of measuring colors in two narrow (2 nm) bandpasses separated by only a few nanometers in wavelength ( 790-794 nm) with measuring colors in two wider (36-58 nm) bandpasses located at bluer ( 666 nm) and redder ( 858 nm) wavelengths. These observations are part of a program to statistically determine the likelihood that planet candidates (e.g., with a given size) ultimately end up being false positives and are complementary to a similar program using warm-Spitzer. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-0802270.
- Publication:
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AAS/Division for Extreme Solar Systems Abstracts
- Pub Date:
- September 2011
- Bibcode:
- 2011ESS.....2.1905C