Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE Spectra

Diogo Souto, Cayman T. Unterborn, Verne V. Smith, Katia Cunha, Johanna Teske, Kevin Covey, Bárbara Rojas-Ayala, D. A. García-Hernández, Keivan Stassun, Olga Zamora, Thomas Masseron, J. A. Johnson, Steven R. Majewski, Henrik Jönsson, Steven Gilhool, Cullen Blake, Felipe Santana

Resultado de la investigación: Article

3 Citas (Scopus)

Resumen

The first detailed chemical abundance analysis of the M-dwarf (M4.0) exoplanet-hosting star Ross 128 is presented here, based upon near-infrared (1.5-1.7 μm), high-resolution (R ∼ 22,500) spectra from the SDSS Apache Point Galactic Evolution Experiment survey. We determined precise atmospheric parameters T eff = 3231 ±100 K, log g = 4.96 ±0.11 dex and chemical abundances of eight elements (C, O, Mg, Al, K, Ca, Ti, and Fe), finding Ross 128 to have near solar metallicity ([Fe/H] = +0.03 ± 0.09 dex). The derived results were obtained via spectral synthesis (1D LTE) adopting both MARCS and PHOENIX model atmospheres; stellar parameters and chemical abundances derived from the different adopted models do not show significant offsets. Mass-radius modeling of Ross 128b indicates that it lies below the pure-rock composition curve, suggesting that it contains a mixture of rock and iron, with the relative amounts of each set by the ratio of Fe/Mg. If Ross 128b formed with a subsolar Si abundance, and assuming the planet's composition matches that of the host star, it likely has a larger core size relative to the Earth despite this producing a planet with a Si/Mg abundance ratio ∼34% greater than the Sun. The derived planetary parameters - insolation flux (S Earth = 1.79 ±0.26) and equilibrium temperature (T eq = 294 ±10 K) - support previous findings that Ross 128b is a temperate exoplanet in the inner edge of the habitable zone.

Idioma originalEnglish
Número de artículoL15
PublicaciónAstrophysical Journal Letters
Volumen860
N.º1
DOI
EstadoPublished - 10 jun 2018

Huella dactilar

extrasolar planets
planets
planet
rocks
insolation
stars
local thermodynamic equilibrium
galactic evolution
rock
metallicity
near infrared
iron
atmospheres
radii
atmosphere
high resolution
curves
synthesis
modeling
chemical

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Citar esto

Souto, D., Unterborn, C. T., Smith, V. V., Cunha, K., Teske, J., Covey, K., ... Santana, F. (2018). Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE Spectra. Astrophysical Journal Letters, 860(1), [L15]. https://doi.org/10.3847/2041-8213/aac896
Souto, Diogo ; Unterborn, Cayman T. ; Smith, Verne V. ; Cunha, Katia ; Teske, Johanna ; Covey, Kevin ; Rojas-Ayala, Bárbara ; García-Hernández, D. A. ; Stassun, Keivan ; Zamora, Olga ; Masseron, Thomas ; Johnson, J. A. ; Majewski, Steven R. ; Jönsson, Henrik ; Gilhool, Steven ; Blake, Cullen ; Santana, Felipe. / Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE Spectra. En: Astrophysical Journal Letters. 2018 ; Vol. 860, N.º 1.
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abstract = "The first detailed chemical abundance analysis of the M-dwarf (M4.0) exoplanet-hosting star Ross 128 is presented here, based upon near-infrared (1.5-1.7 μm), high-resolution (R ∼ 22,500) spectra from the SDSS Apache Point Galactic Evolution Experiment survey. We determined precise atmospheric parameters T eff = 3231 ±100 K, log g = 4.96 ±0.11 dex and chemical abundances of eight elements (C, O, Mg, Al, K, Ca, Ti, and Fe), finding Ross 128 to have near solar metallicity ([Fe/H] = +0.03 ± 0.09 dex). The derived results were obtained via spectral synthesis (1D LTE) adopting both MARCS and PHOENIX model atmospheres; stellar parameters and chemical abundances derived from the different adopted models do not show significant offsets. Mass-radius modeling of Ross 128b indicates that it lies below the pure-rock composition curve, suggesting that it contains a mixture of rock and iron, with the relative amounts of each set by the ratio of Fe/Mg. If Ross 128b formed with a subsolar Si abundance, and assuming the planet's composition matches that of the host star, it likely has a larger core size relative to the Earth despite this producing a planet with a Si/Mg abundance ratio ∼34{\%} greater than the Sun. The derived planetary parameters - insolation flux (S Earth = 1.79 ±0.26) and equilibrium temperature (T eq = 294 ±10 K) - support previous findings that Ross 128b is a temperate exoplanet in the inner edge of the habitable zone.",
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author = "Diogo Souto and Unterborn, {Cayman T.} and Smith, {Verne V.} and Katia Cunha and Johanna Teske and Kevin Covey and B{\'a}rbara Rojas-Ayala and Garc{\'i}a-Hern{\'a}ndez, {D. A.} and Keivan Stassun and Olga Zamora and Thomas Masseron and Johnson, {J. A.} and Majewski, {Steven R.} and Henrik J{\"o}nsson and Steven Gilhool and Cullen Blake and Felipe Santana",
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Souto, D, Unterborn, CT, Smith, VV, Cunha, K, Teske, J, Covey, K, Rojas-Ayala, B, García-Hernández, DA, Stassun, K, Zamora, O, Masseron, T, Johnson, JA, Majewski, SR, Jönsson, H, Gilhool, S, Blake, C & Santana, F 2018, 'Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE Spectra', Astrophysical Journal Letters, vol. 860, n.º 1, L15. https://doi.org/10.3847/2041-8213/aac896

Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE Spectra. / Souto, Diogo; Unterborn, Cayman T.; Smith, Verne V.; Cunha, Katia; Teske, Johanna; Covey, Kevin; Rojas-Ayala, Bárbara; García-Hernández, D. A.; Stassun, Keivan; Zamora, Olga; Masseron, Thomas; Johnson, J. A.; Majewski, Steven R.; Jönsson, Henrik; Gilhool, Steven; Blake, Cullen; Santana, Felipe.

En: Astrophysical Journal Letters, Vol. 860, N.º 1, L15, 10.06.2018.

Resultado de la investigación: Article

TY - JOUR

T1 - Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE Spectra

AU - Souto, Diogo

AU - Unterborn, Cayman T.

AU - Smith, Verne V.

AU - Cunha, Katia

AU - Teske, Johanna

AU - Covey, Kevin

AU - Rojas-Ayala, Bárbara

AU - García-Hernández, D. A.

AU - Stassun, Keivan

AU - Zamora, Olga

AU - Masseron, Thomas

AU - Johnson, J. A.

AU - Majewski, Steven R.

AU - Jönsson, Henrik

AU - Gilhool, Steven

AU - Blake, Cullen

AU - Santana, Felipe

PY - 2018/6/10

Y1 - 2018/6/10

N2 - The first detailed chemical abundance analysis of the M-dwarf (M4.0) exoplanet-hosting star Ross 128 is presented here, based upon near-infrared (1.5-1.7 μm), high-resolution (R ∼ 22,500) spectra from the SDSS Apache Point Galactic Evolution Experiment survey. We determined precise atmospheric parameters T eff = 3231 ±100 K, log g = 4.96 ±0.11 dex and chemical abundances of eight elements (C, O, Mg, Al, K, Ca, Ti, and Fe), finding Ross 128 to have near solar metallicity ([Fe/H] = +0.03 ± 0.09 dex). The derived results were obtained via spectral synthesis (1D LTE) adopting both MARCS and PHOENIX model atmospheres; stellar parameters and chemical abundances derived from the different adopted models do not show significant offsets. Mass-radius modeling of Ross 128b indicates that it lies below the pure-rock composition curve, suggesting that it contains a mixture of rock and iron, with the relative amounts of each set by the ratio of Fe/Mg. If Ross 128b formed with a subsolar Si abundance, and assuming the planet's composition matches that of the host star, it likely has a larger core size relative to the Earth despite this producing a planet with a Si/Mg abundance ratio ∼34% greater than the Sun. The derived planetary parameters - insolation flux (S Earth = 1.79 ±0.26) and equilibrium temperature (T eq = 294 ±10 K) - support previous findings that Ross 128b is a temperate exoplanet in the inner edge of the habitable zone.

AB - The first detailed chemical abundance analysis of the M-dwarf (M4.0) exoplanet-hosting star Ross 128 is presented here, based upon near-infrared (1.5-1.7 μm), high-resolution (R ∼ 22,500) spectra from the SDSS Apache Point Galactic Evolution Experiment survey. We determined precise atmospheric parameters T eff = 3231 ±100 K, log g = 4.96 ±0.11 dex and chemical abundances of eight elements (C, O, Mg, Al, K, Ca, Ti, and Fe), finding Ross 128 to have near solar metallicity ([Fe/H] = +0.03 ± 0.09 dex). The derived results were obtained via spectral synthesis (1D LTE) adopting both MARCS and PHOENIX model atmospheres; stellar parameters and chemical abundances derived from the different adopted models do not show significant offsets. Mass-radius modeling of Ross 128b indicates that it lies below the pure-rock composition curve, suggesting that it contains a mixture of rock and iron, with the relative amounts of each set by the ratio of Fe/Mg. If Ross 128b formed with a subsolar Si abundance, and assuming the planet's composition matches that of the host star, it likely has a larger core size relative to the Earth despite this producing a planet with a Si/Mg abundance ratio ∼34% greater than the Sun. The derived planetary parameters - insolation flux (S Earth = 1.79 ±0.26) and equilibrium temperature (T eq = 294 ±10 K) - support previous findings that Ross 128b is a temperate exoplanet in the inner edge of the habitable zone.

KW - infrared: stars

KW - planetary systems

KW - planetstar interactions

KW - stars: abundances

KW - stars: fundamental parameters

KW - stars: low-mass

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