Murphy, SJ;
Joyce, M;
Bedding, TR;
White, TR;
Kama, M;
(2021)
A precise asteroseismic age and metallicity for HD139614: a pre-main-sequence star with a protoplanetary disc in Upper Centaurus-Lupus.
Monthly Notices of the Royal Astronomical Society
, 502
(2)
pp. 1633-1646.
10.1093/mnras/stab144.
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Abstract
HD 139614 is known to be a ∼14-Myr-old, possibly pre-main-sequence star in the Sco-Cen OB association in the Upper Centaurus-Lupus subgroup, with a slightly warped circumstellar disc containing ring structures hinting at one or more planets. The star’s chemical abundance pattern is metal-deficient except for volatile elements, which places it in the λ Boo class and suggests it has recently accreted gas-rich but dust-poor material. We identify seven dipole and four radial pulsation modes among its δ Sct pulsations using the TESS light curve and an échelle diagram. Precision modelling with the MESA stellar evolution and GYRE stellar oscillation programs confirms it is on the pre-main sequence. Asteroseismic, grid-based modelling suggests an age of 10.75 ± 0.77 Myr, a mass of 1.52 ± 0.02 M ⊙, and a global metal abundance of Z = 0.0100 ± 0.0010. This represents the first asteroseismic determination of the bulk metallicity of a λ Boo star. The precise age and metallicity offer a benchmark for age estimates in Upper Centaurus–Lupus, and for understanding disc retention and planet formation around intermediate-mass stars.
| Type: | Article |
|---|---|
| Title: | A precise asteroseismic age and metallicity for HD139614: a pre-main-sequence star with a protoplanetary disc in Upper Centaurus-Lupus |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stab144 |
| Publisher version: | https://doi.org/10.1093/mnras/stab144 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | asteroseismology, protoplanetary discs, stars: chemically peculiar, stars: fundamental parameters, stars: pre-main-sequence, variables: Scuti, LAMBDA BOOTIS STARS, OBSERVED LUMINOSITY SPREAD, DELTA-SCUTI STARS, CHEMICAL-COMPOSITION, STELLAR EVOLUTION, MIXING-LENGTH, PULSATIONAL CHARACTERISTICS, NONRADIAL OSCILLATIONS, CONVECTIVE BOUNDARIES, ELEMENT DIFFUSION |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10137887 |
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