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

Abstract

We used Kepler photometry to determine the internal rotation rate of KIC 7661054, a chemically normal γ 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-σ 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.

Spectroscopic and asteroseismic analysis of the remarkable main-sequence A star KIC 11145123

“…similar analyses have been carried out for other A/F stars (Saio et al 2015;Schmid & Aerts 2016;Murphy et al 2016), each showing near-uniform core-to-surface rotation in stars near the terminal age main-sequence (TAMS).…”

“…(4) Our analysis of [Li/Fe] (Saio et al 2015;Schmid & Aerts 2016;Murphy et al 2016). It is true that there is a selection effect in these first studies of core-to-surface rotation in that the rotational splitting in the nonradial mode multiplets is easier to see for slow rotation.…”

Starquakes spring stellar surprises

“…Interior rotation properties have been deduced for hydrogen-burning main-sequence phases (Kurtz et al 2014, Saio et al 2015, Triana et al 2015, Murphy et al 2016, Schmid & Aerts 2016) subgiant and red giant phases (Beck et al 2012, Mosser 2012, Deheuvels et al 2012, Deheuvels et al 2014, Deheuvels et al 2015, and the late evolutionary stages of subdwarf B stars (Van Grootel et al 2009) and white dwarfs (Charpinet et al 2009). …”

“…Parts of the section "Angular momentum transport in stars" are based on the introduction of Murphy et al (2016) and used by permission of OUP.…”

Constraining the near-core rotation of theγDoradus star 43 Cygni using BRITE-Constellation data

“…They have since been used to probe the rotation rates (e.g, Murphy et al 2016;Van Reeth et al 2016;Ouazzani et al 2017;Sowicka et al 2017;Guo et al 2017) and the nature of the mixing processes (e.g., Schmid & Aerts 2016) in the deep interior of these stars. This provides us with an opportunity to independently evaluate the rotational mixing and angular momentum transport mechanisms inside intermediate-mass stars.…”