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Chemical Abundances of M-Dwarfs from the Apogee Survey. I. the Exoplanet Hosting Stars Kepler-138 and Kepler-186

Souto, D. ; Cunha, K. ; García-Hernández, D. A. ; Zamora, O. ; Prieto, C. Allende ; Smith, V. V. ; Mahadevan, S. ; Blake, C. LU ; Johnson, J. A. and Jönsson, H. LU orcid , et al. (2017) In Astrophysical Journal 835(2).
Abstract


We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution (R ∼ 22,500) H-band spectra from the SDSS-IV-APOGEE survey. Chemical abundances of 13 elements - C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe - are extracted from the APOGEE spectra of these early M-dwarfs via spectrum syntheses computed with an improved line list that takes into account H
2
O and FeH lines. This paper demonstrates that APOGEE spectra can be analyzed to determine detailed chemical compositions of M-dwarfs. Both exoplanet-hosting M-dwarfs display modest... (More)


We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution (R ∼ 22,500) H-band spectra from the SDSS-IV-APOGEE survey. Chemical abundances of 13 elements - C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe - are extracted from the APOGEE spectra of these early M-dwarfs via spectrum syntheses computed with an improved line list that takes into account H
2
O and FeH lines. This paper demonstrates that APOGEE spectra can be analyzed to determine detailed chemical compositions of M-dwarfs. Both exoplanet-hosting M-dwarfs display modest sub-solar metallicities: [Fe/H]
Kepler-138
= -0.09 ± 0.09 dex and [Fe/H]
Kepler-186
= -0.08 ± 0.10 dex. The measured metallicities resulting from this high-resolution analysis are found to be higher by ∼0.1-0.2 dex than previous estimates from lower-resolution spectra. The C/O ratios obtained for the two planet-hosting stars are near-solar, with values of 0.55 ± 0.10 for Kepler-138 and 0.52 ± 0.12 for Kepler-186. Kepler-186 exhibits a marginally enhanced [Si/Fe] ratio.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
infrared: stars, planet-star interactions, planetary systems, stars: abundances, stars: fundamental parameters, stars: low-mass
in
Astrophysical Journal
volume
835
issue
2
article number
239
publisher
American Astronomical Society
external identifiers
  • scopus:85011965991
ISSN
0004-637X
DOI
10.3847/1538-4357/835/2/239
language
English
LU publication?
yes
id
2a8720e8-720f-454e-b3ea-63622364887a
date added to LUP
2019-05-06 11:49:13
date last changed
2024-04-16 04:25:56
@article{2a8720e8-720f-454e-b3ea-63622364887a,
  abstract     = {{<p><br>
                            We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution (R ∼ 22,500) H-band spectra from the SDSS-IV-APOGEE survey. Chemical abundances of 13 elements - C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe - are extracted from the APOGEE spectra of these early M-dwarfs via spectrum syntheses computed with an improved line list that takes into account H<br>
                            <sub>2</sub><br>
                            O and FeH lines. This paper demonstrates that APOGEE spectra can be analyzed to determine detailed chemical compositions of M-dwarfs. Both exoplanet-hosting M-dwarfs display modest sub-solar metallicities: [Fe/H]<br>
                            <sub>Kepler-138</sub><br>
                             = -0.09 ± 0.09 dex and [Fe/H]<br>
                            <sub>Kepler-186</sub><br>
                             = -0.08 ± 0.10 dex. The measured metallicities resulting from this high-resolution analysis are found to be higher by ∼0.1-0.2 dex than previous estimates from lower-resolution spectra. The C/O ratios obtained for the two planet-hosting stars are near-solar, with values of 0.55 ± 0.10 for Kepler-138 and 0.52 ± 0.12 for Kepler-186. Kepler-186 exhibits a marginally enhanced [Si/Fe] ratio.<br>
                        </p>}},
  author       = {{Souto, D. and Cunha, K. and García-Hernández, D. A. and Zamora, O. and Prieto, C. Allende and Smith, V. V. and Mahadevan, S. and Blake, C. and Johnson, J. A. and Jönsson, H. and Pinsonneault, M. and Holtzman, J. and Majewski, S. R. and Shetrone, M. and Teske, J. and Nidever, D. and Schiavon, R. and Sobeck, J. and Pérez, A. E.García and Chew, Y. Gómez Maqueo and Stassun, K.}},
  issn         = {{0004-637X}},
  keywords     = {{infrared: stars; planet-star interactions; planetary systems; stars: abundances; stars: fundamental parameters; stars: low-mass}},
  language     = {{eng}},
  month        = {{02}},
  number       = {{2}},
  publisher    = {{American Astronomical Society}},
  series       = {{Astrophysical Journal}},
  title        = {{Chemical Abundances of M-Dwarfs from the Apogee Survey. I. the Exoplanet Hosting Stars Kepler-138 and Kepler-186}},
  url          = {{http://dx.doi.org/10.3847/1538-4357/835/2/239}},
  doi          = {{10.3847/1538-4357/835/2/239}},
  volume       = {{835}},
  year         = {{2017}},
}