ADAPTIVE OPTICS IMAGES OF<i>KEPLER</i>OBJECTS OF INTEREST

Abstract

All transiting planets are at risk of contamination by blends with nearby,\nunresolved stars. Blends dilute the transit signal, causing the planet to\nappear smaller than it really is, or produce a false positive detection when\nthe target star is blended with eclipsing binary stars. This paper reports on\nhigh spatial-resolution adaptive optics images of 90 Kepler planetary\ncandidates. Companion stars are detected as close as 0.1 arcsec from the target\nstar. Images were taken in the near-infrared (J and Ks bands) with ARIES on the\nMMT and PHARO on the Palomar Hale 200-inch. Most objects (60%) have at least\none star within 6 arcsec separation and a magnitude difference of 9. Eighteen\nobjects (20%) have at least one companion within 2 arcsec of the target star; 6\ncompanions (7%) are closer than 0.5 arcsec. Most of these companions were\npreviously unknown, and the associated planetary candidates should receive\nadditional scrutiny. Limits are placed on the presence of additional companions\nfor every system observed, which can be used to validate planets statistically\nusing the BLENDER method. Validation is particularly critical for low-mass,\npotentially Earth-like worlds, which are not detectable with current-generation\nradial velocity techniques. High-resolution images are thus a crucial component\nof any transit follow-up program.\n