A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper Centaurus–Lupus

Murphy, Simon J. and Joyce, Meridith and Bedding, Timothy R. and White, Timothy R. and Kama, Mihkel (2021) A precise asteroseismic age and metallicity for HD 139614: 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. ISSN 0035-8711

[img]
Preview
Text (Published Version)
A precise asteroseismic age and metallicity for HD 139614- a pre-main-sequence star with a protoplanetary disc in Upper Centaurus–Lupus (Murphy et al 2021a).pdf

Download (5MB) | Preview

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.


Statistics for USQ ePrint 47924
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: File reproduced in accordance with the copyright policy of the publisher/author.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 12 Jul 2022 22:29
Last Modified: 13 Jul 2022 00:15
Uncontrolled 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
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
Socio-Economic Objectives (2020): 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280120 Expanding knowledge in the physical sciences
Identification Number or DOI: https://doi.org/10.1093/mnras/stab144
URI: http://eprints.usq.edu.au/id/eprint/47924

Actions (login required)

View Item Archive Repository Staff Only