Exploring the Convective Core of the Hybrid δ Scutiγ Doradus Star CoRoT 100866999 with Asteroseismology
Abstract
We computed a grid of theoretical models to fit the δ Scuti frequencies of CoRoT 100866999 detected earlier from the CoRoT time serials. The pulsating primary star is determined to be a mainsequence star with a rotation period of {4.1}_{0.5}^{+0.6} days, rotating slower than the orbital motion. The fundamental parameters of the primary star are determined to be M={1.71}_{0.04}^{+0.13} {M}_{⊙ }, Z={0.012}_{0.000}^{+0.004}, {f}_{ov}}={0.02}_{0.02}^{+0.00}, {T}_{eff}}={8024}_{297}^{+249} K, L={11.898}_{1.847}^{+2.156} {L}_{⊙ }, {log}g={4.166}_{0.002}^{+0.013}, R={1.787}_{0.016}^{+0.040} {R}_{⊙ }, and {X}_{{{c}}}={0.488}_{0.020}^{+0.011}, matching those obtained from the eclipsing lightcurve analysis. Based on the model fittings, p _{1} and p _{5} are suggested to be two dipole modes, and p _{3}, p _{4}, p _{6}, and p _{7} are suggested to be four quadrupole modes. In particular, p _{4} and p _{7} are identified as two components of one quintuplet. Based on the bestfitting model, we find that p _{1} is a g mode and the other nonradial modes have pronounced mixed characters, which give strong constraints on the convective core. Finally, the relative size of the convective core of CoRoT 100866999 is determined to {R}_{conv}}/R={0.0931}_{0.0013}^{+0.0003}.
 Publication:

The Astrophysical Journal
 Pub Date:
 December 2019
 DOI:
 10.3847/15384357/ab585b
 arXiv:
 arXiv:1911.06941
 Bibcode:
 2019ApJ...887..253C
 Keywords:

 Asteroseismology;
 Delta Scuti variable stars;
 Pulsating variable stars;
 Gamma Doradus variable stars;
 73;
 370;
 1307;
 2101;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 7 figures and 6 tables. accepted by ApJ