Asteroseismology of 1400 new red giants from Kepler data
Jie Yu (Sydney Institute for Astronomy, School of Physics, University of Sydney ), Daniel Huber (Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006, Australia), Timothy R. Bedding (Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006, Australia), Dennis Stello (Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006, Australia)

We report the discovery of solar-like oscillations in 1400 new Kepler red giants which have previously been misclassified as subgiants, with predicted numax values (based on the KIC) ranging between 280 μHz to 700 μHz. The sample enlarges the known number of oscillating low-luminosity red giants by 40% (from 1874 to 2630), and includes over a dozen new seismic planet-candidate host stars. About three quarters of our sample are classified as ascending red-giant-branch stars, while the remaining stars are red-clump stars. A novel scheme was applied to determine ∆ν for 93 stars with νmax close to the Nyquist frequency (240 μHz < νmax < 320 μHz). Additionally, we identified 47 stars residing in the super-Nyquist frequency regime up to 387 μHz using long-cadence light curves. We show that the misclassifications are most likely due to large random uncertainties in KIC surface gravities, and do not result from the absence of broadband colors or from different physical properties such as reddening, spatial distribution, mass or metallicity. The new sample allows us to study oscillations in low-luminosity red giants, and to characterize planet candidates around those stars.