Masses, Oxygen and Carbon abundances in CHEPS dwarf stars. (arXiv:1811.05011v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Pavlenko_Y/0/1/0/all/0/1">Y.V. Pavlenko</a> (MAO, CAR UH, NCAC), <a href="http://arxiv.org/find/astro-ph/1/au:+Kaminsky_B/0/1/0/all/0/1">B.M. Kaminsky</a> (MAO), <a href="http://arxiv.org/find/astro-ph/1/au:+Jenkins_J/0/1/0/all/0/1">J.S. Jenkins</a> (CATA, UH), <a href="http://arxiv.org/find/astro-ph/1/au:+Ivanyuk_O/0/1/0/all/0/1">O.M. Ivanyuk</a> (MAO), <a href="http://arxiv.org/find/astro-ph/1/au:+Jones_H/0/1/0/all/0/1">H.R.A. Jones</a> (CAR UH), <a href="http://arxiv.org/find/astro-ph/1/au:+Lyubchik_Y/0/1/0/all/0/1">Yu.P. Lyubchik</a> (MAO)
Context. We report the results from the determination of stellar masses,
carbon and oxygen abundances in the atmospheres of 107 stars from the CHEPS
program. Our stars are drawn from a population with a significantly super-solar
metallicity. At least 10 of these stars are known to host orbiting planets.
Aims. In this work, we set out to understand the behavior of carbon and
oxygen abundance in stars with different spectral classes, metallicities and V
sin i , within the metal-rich stellar population.
Methods. Masses of these stars were determined using the data from Gaia DR2
release. The oxygen and carbon abundances were determined by fitting the
absorption lines. Oxygen abundances were determined by fits to the 6300.304 A O
I line and for the determination of the carbon abundances we used 3 lines of
the C I atom and 12 lines of C2 molecule.
Results. We determine masses and abundances of 107 CHEPS stars. There is no
evidence that the [C/O] ratio depends on V sin i or the mass of the star,
within our constrained range of masses, i.e. 0.82 < Mstar/Msun < 1.5 and
metallicities -0.27 < [Fe=H] < +0.39 and we confirm that metal-rich dwarf stars
with planets are more carbon-rich in comparison with non-planet host stars,
with a statistical signifcance of 96%.
Conclusions. We find tentative evidence that there is a slight offset to
lower abundance and a greater dispersion in oxygen abundances relative to
carbon, and interpret this as potentially arising from the production of the
oxygen being more effective at more metal-rich epochs. We also find evidence
that for lower mass star’s the angular momentum loss in star’s with planets as
measured by V sin i is steeper than star’s without planets. In general, we find
that the fast rotators (V sin i > 5 km/s) are massive stars.
Context. We report the results from the determination of stellar masses,
carbon and oxygen abundances in the atmospheres of 107 stars from the CHEPS
program. Our stars are drawn from a population with a significantly super-solar
metallicity. At least 10 of these stars are known to host orbiting planets.
Aims. In this work, we set out to understand the behavior of carbon and
oxygen abundance in stars with different spectral classes, metallicities and V
sin i , within the metal-rich stellar population.
Methods. Masses of these stars were determined using the data from Gaia DR2
release. The oxygen and carbon abundances were determined by fitting the
absorption lines. Oxygen abundances were determined by fits to the 6300.304 A O
I line and for the determination of the carbon abundances we used 3 lines of
the C I atom and 12 lines of C2 molecule.
Results. We determine masses and abundances of 107 CHEPS stars. There is no
evidence that the [C/O] ratio depends on V sin i or the mass of the star,
within our constrained range of masses, i.e. 0.82 < Mstar/Msun < 1.5 and
metallicities -0.27 < [Fe=H] < +0.39 and we confirm that metal-rich dwarf stars
with planets are more carbon-rich in comparison with non-planet host stars,
with a statistical signifcance of 96%.
Conclusions. We find tentative evidence that there is a slight offset to
lower abundance and a greater dispersion in oxygen abundances relative to
carbon, and interpret this as potentially arising from the production of the
oxygen being more effective at more metal-rich epochs. We also find evidence
that for lower mass star’s the angular momentum loss in star’s with planets as
measured by V sin i is steeper than star’s without planets. In general, we find
that the fast rotators (V sin i > 5 km/s) are massive stars.
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