Periodicities in KIC 3527751 from 3yr Kepler data

Period spacing sequences indicate l=1 and 2 overtone spacings of 266.4+/-0.2 and 153.2+/-0.2s, respectively. We also calculate reduced periods, from which we find evidence of trapped pulsations. Such mode trappings can be used to constrain the core/atmosphere transition layers.

Interestingly, frequency multiplets in the g-mode region, which sample deep into the star, indicate a rotation period of 42.6+/-3.4days while p-mode multiplets, which sample the outer envelope, indicate a rotation period of 15.3+/-0.7days. We interpret this as differential rotation in the radial direction with the core rotating more slowly. This is the first example of differential rotation for a sdB star.