alpha Centauri A as a potential stellar model calibrator: establishing the nature of its core

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Nsamba, B (Author) Other; Monteiro, MJPFG (Author) FCUP; Campante, TL (Author) Other; Cunha, MS (Author) Other; Sousa, SG (Author) Other

Journal

Title: Monthly Notices of the Royal Astronomical Society

Vol. 479

Pages: L55-L59

ISSN: 0035-8711

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 10 Citations

ISI Web of Science

Scopus - 11 Citations

Scientific classification

CORDIS: Physical sciences > Astronomy

Other information

Authenticus ID: P-00P-MFA

DOI: 10.1093/mnrasl/sly092

Abstract (EN): Understanding the physical process responsible for the transport of energy in the core of alpha Centauri A is of the utmost importance if this star is to be used in the calibration of stellar model physics. Adoption of different parallax measurements available in the literature results in differences in the interferometric radius constraints used in stellar modelling. Further, this is at the origin of the different dynamical mass measurements reported for this star. With the goal of reproducing the revised dynamical mass derived by Pourbaix & Boffin, we modelled the star using two stellar grids varying in the adopted nuclear reaction rates. Asteroseismic and spectroscopic observables were complemented with different interferometric radius constraints during the optimization procedure. Our findings show that best-fitting models reproducing the revised dynamical mass favour the existence of a convective core (greater than or similar to 70 per cent of best-fitting models), a result that is robust against changes to the model physics. If this mass is accurate, then alpha Centauri A may be used to calibrate stellar model parameters in the presence of a convective core.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5