Near-uniform internal rotation of the main-sequence gamma Doradus pulsator KIC 7661054

作者：Murphy Simon J; Fossati Luca; Bedding Timothy R; Saio Hideyuki; Kurtz Donald W; Grassitelli Luca; Wang Edric S

来源：Monthly Notices of the Royal Astronomical Society, 2016, 459(2): 1201-1212.

DOI：10.1093/mnras/stw705

• asteroseismology
• techniques: spectroscopic
• stars: individual: KIC 7660154
• stars: oscillations
• stars: rotation

We used Kepler photometry to determine the internal rotation rate of KIC 7661054, a chemically normal gamma Dor star on the main sequence at spectral type F2.5 V. The core rotation period of 27.25 +/- 0.06 d is obtained from the rotational splittings of a series of dipole g modes. The surface rotation period is calculated from a spectroscopic projected rotation velocity and a stellar radius computed from models. Literature data, obtained without inclusion of macroturbulence as a line-broadening mechanism, imply that the surface rotates much more quickly than the core, while our detailed analysis suggests that the surface may rotate slightly more quickly than the core and that the rotation profile is uniform within the 1 sigma uncertainties. We discuss the pitfalls associated with the determination of surface rotation rates of slow rotators from spectroscopy in the absence of asteroseismic constraints. A broad signal is observed at low frequency, which we show cannot be attributed to rotation, contrary to previous suggestions concerning the origin of such signals.

• 出版日期2016-6-21