Adaptive optics (AO) imaging corrects wavefront distortions caused by turbulence in the atmosphere using deformable mirrors, allowing observations near the diffraction limit of the telescope. This enables the detection of close companions to stars that would otherwise remain unresolved, and measured contrast ratios in different passbands can be used to identify the nature of these companions.
Our group is involved in several projects using adaptive optics to study the effect of stellar companions on stars and their planets. In collaboration with Christoph Baranec and Eric Gaidos our group have launched the first dedicated campaign to detect companions to oscillating Kepler stars using Robo-AO combined with 8-m class telescopes on Mauna Kea (such as Keck and Subaru). The detections allow us to investigate the influence of companions on the oscillations of the primary star, as well as precisely measure the age of low-mass secondaries through the asteroseismic analysis of the primary star (if the stars are gravitationally bound). We are also involved in surveys investigating the effect of binaries on the occurrence rate of exoplanets, in collaboration with Adam Kraus and Trent Dupuy.