The envelope of the power spectra of over a thousand δ Scuti stars

The T̅_eff − ν_max scaling relation^★

¹ Departamento de Astrofísica, Centro de Astrobiología (CSIC – INTA), ESAC, 28691 Villanueva de la Cañada, Madrid, Spain
e-mail: sbarcelo@cab.inta-csic.es
² Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain
³ Departamento de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain
⁴ Laboratoire AIM, CEA/DRF – CNRS – Univ. Paris Diderot – IRFU/SAp, Centre de Saclay, 91191 Gif-sur-Yvette Cedex, France

Received: 20 August 2017
Accepted: 16 February 2018

Abstract

CoRoT and Kepler high-precision photometric data allowed the detection and characterization of the oscillation parameters in stars other than the Sun. Moreover, thanks to the scaling relations, it is possible to estimate masses and radii for thousands of solar-type oscillating stars. Recently, a Δν − ρ relation has been found for δ Scuti stars. Now, analysing several hundreds of this kind of stars observed with CoRoT and Kepler, we present an empiric relation between their frequency at maximum power of their oscillation spectra and their effective temperature. Such a relation can be explained with the help of the κ-mechanism and the observed dispersion of the residuals is compatible with they being caused by the gravity-darkening effect.