Ref: SCART-2020-0010

The first view of Delta Scuti and Gamma Doradus stars with the TESS mission

Antoci, V. ; Cunha, M. S. ; Bowman, D. M. ; and 63, more ; (incl. De Cat, P. ; and Lampens, P.)

published in Monthly Notices of the Royal Astronomical Society, 490, pp. 4040-4059 (2019)

Abstract: We present the first asteroseismic results for Delta Scuti and Gamma Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilize the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding variability and place them in the Hertzsprung-Russell diagram using Gaia DR2 data. Included within our sample are the eponymous members of two pulsator classes, Gamma Doradus and SX Phoenicis. Our sample of pulsating intermediate-mass stars observed by TESS also allows us to confront theoretical models of pulsation driving in the classical instability strip for the first time and show that mixing processes in the outer envelope play an important role. We derive an empirical estimate of 74 per cent for the relative amplitude suppression factor as a result of the redder TESS passband compared to the Kepler mission using a pulsating eclipsing binary system. Furthermore, our sample contains many high-frequency pulsators, allowing us to probe the frequency variability of hot young Delta Scuti stars, which were lacking in the Kepler mission data set, and identify promising targets for future asteroseismic modelling. The TESS data also allow us to refine the stellar parameters of SX Phoenicis, which is believed to be a blue straggler.

Keyword(s): asteroseismology; techniques: photometric; stars: chemically peculiar; stars: interiors; stars: variables: δ Scuti; Astrophysics - Solar and Stellar Astrophysics
DOI: 10.1093/mnras/stz2787

The record appears in these collections:
Royal Observatory of Belgium > Astronomy & Astrophysics
Science Articles > Peer Reviewed Articles

 Record created 2020-01-14, last modified 2020-01-14