A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper Centaurus–Lupus
Article
Article Title | A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper Centaurus–Lupus |
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ERA Journal ID | 1074 |
Article Category | Article |
Authors | Murphy, Simon J. (Author), Joyce, Meridith (Author), Bedding, Timothy R. (Author), White, Timothy R. (Author) and Kama, Mihkel (Author) |
Journal Title | Monthly Notices of the Royal Astronomical Society |
Journal Citation | 502 (2), pp. 1633-1646 |
Number of Pages | 13 |
Year | 2021 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 0035-8711 |
1365-2966 | |
Digital Object Identifier (DOI) | https://doi.org/10.1093/mnras/stab144 |
Web Address (URL) | https://academic.oup.com/mnras/article/502/2/1633/6105331 |
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 echelle 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. |
Keywords | asteroseismology; protoplanetary discs; stars: chemically peculiar; stars: fundamental parameters; stars: pre-main-sequence; variables: Scuti; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2021 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Byline Affiliations | University of Sydney |
Australian National University | |
University College London, United Kingdom | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q73qq/a-precise-asteroseismic-age-and-metallicity-for-hd-139614-a-pre-main-sequence-star-with-a-protoplanetary-disc-in-upper-centaurus-lupus
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