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

Simon J. Murphy; Meridith Joyce; Timothy R. Bedding; Timothy R. White; Mihkel Kama

doi:10.1093/mnras/stab144

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

Simon J. Murphy^*, Meridith Joyce^*, Timothy R. Bedding, Timothy R. White, Mihkel Kama

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

51 Citations (Scopus)

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 δSct 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.

Original language	English
Pages (from-to)	1633-1646
Number of pages	14
Journal	Monthly Notices of the Royal Astronomical Society
Volume	502
Issue number	2
DOIs	https://doi.org/10.1093/mnras/stab144
Publication status	Published - 1 Apr 2021

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

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 δSct pulsations using the TESS light curve and an {\'e}chelle 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",

author = "Murphy, \{Simon J.\} and Meridith Joyce and Bedding, \{Timothy R.\} and White, \{Timothy R.\} and Mihkel Kama",

note = "Publisher Copyright: {\textcopyright} 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.",

year = "2021",

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doi = "10.1093/mnras/stab144",

language = "English",

volume = "502",

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T1 - A precise asteroseismic age and metallicity for HD 139614

T2 - A pre-main-sequence star with a protoplanetary disc in Upper Centaurus-Lupus

AU - Murphy, Simon J.

AU - Joyce, Meridith

AU - Bedding, Timothy R.

AU - White, Timothy R.

AU - Kama, Mihkel

PY - 2021/4/1

Y1 - 2021/4/1

N2 - 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 δSct 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.

AB - 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 δSct 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.

KW - asteroseismology

KW - protoplanetary discs

KW - stars: chemically peculiar

KW - stars: fundamental parameters

KW - stars: pre-main-sequence

KW - variables: Scuti

UR - https://www.scopus.com/pages/publications/85102375356

U2 - 10.1093/mnras/stab144

DO - 10.1093/mnras/stab144

M3 - Article

SN - 0035-8711

VL - 502

SP - 1633

EP - 1646

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 2

ER -

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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