High-resolution spectroscopic study of dwarf stars in the northern sky: Na to Zn abundances in two fields with radii of 20 degrees. (arXiv:1907.09157v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Mikolaitis_S/0/1/0/all/0/1">Šarūnas Mikolaitis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Drazdauskas_A/0/1/0/all/0/1">Arnas Drazdauskas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Minkeviciute_R/0/1/0/all/0/1">Renata Minkevičiūtė</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stonkute_E/0/1/0/all/0/1">Edita Stonkutė</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tautvaisiene_G/0/1/0/all/0/1">Gražina Tautvaišienė</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Klebonas_L/0/1/0/all/0/1">Lukas Klebonas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bagdonas_V/0/1/0/all/0/1">Vilius Bagdonas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paksiene_E/0/1/0/all/0/1">Erika Pakšienė</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Janulis_R/0/1/0/all/0/1">Rimvydas Janulis</a>
New space missions, such as NASA TESS or ESA PLATO, will focus on bright
stars, which have been largely ignored by modern large surveys, especially in
the northern sky. Spectroscopic information is of paramount importance in
characterising the stars and analysing planets possibly orbiting them, and in
studying the Galactic disc evolution. The aim of this work was to analyse all
bright (V < 8 mag) F, G, and K dwarf stars using high-resolution spectra in the
selected sky fields near the northern celestial pole. The observations were
carried out with the 1.65 m diameter telescope at the Mol.{e}tai Astronomical
Observatory and a fibre-fed high-resolution spectrograph covering a full
visible wavelength range (400-850 nm). The atmospheric parameters were derived
using the classical equivalent width approach while the individual chemical
element abundances were determined from spectral synthesis. For both tasks the
one-dimensional plane-parallel LTE MARCS stellar model atmospheres were
applied. Results. We determined the main atmospheric parameters, kinematic
properties, orbital parameters, and stellar ages for 109 newly observed stars
and chemical abundances of 23 chemical species for 249 F, G, and K dwarf stars
observed in the present study and in our previous study. The [MgI/FeI] ratio
was adopted to define the thin-disc ($alpha$-poor) and thick-disc
($alpha$-rich) stars in our sample. We explored the behaviour of 21 chemical
species in the [El/FeI] versus [FeI/H] and [El/FeI] versus age planes, and
compared the results with the latest Galactic chemical evolution models. We
also explored [El/FeI] gradients according to the mean Galactocentric distances
and maximum height above the Galactic plane.
New space missions, such as NASA TESS or ESA PLATO, will focus on bright
stars, which have been largely ignored by modern large surveys, especially in
the northern sky. Spectroscopic information is of paramount importance in
characterising the stars and analysing planets possibly orbiting them, and in
studying the Galactic disc evolution. The aim of this work was to analyse all
bright (V < 8 mag) F, G, and K dwarf stars using high-resolution spectra in the
selected sky fields near the northern celestial pole. The observations were
carried out with the 1.65 m diameter telescope at the Mol.{e}tai Astronomical
Observatory and a fibre-fed high-resolution spectrograph covering a full
visible wavelength range (400-850 nm). The atmospheric parameters were derived
using the classical equivalent width approach while the individual chemical
element abundances were determined from spectral synthesis. For both tasks the
one-dimensional plane-parallel LTE MARCS stellar model atmospheres were
applied. Results. We determined the main atmospheric parameters, kinematic
properties, orbital parameters, and stellar ages for 109 newly observed stars
and chemical abundances of 23 chemical species for 249 F, G, and K dwarf stars
observed in the present study and in our previous study. The [MgI/FeI] ratio
was adopted to define the thin-disc ($alpha$-poor) and thick-disc
($alpha$-rich) stars in our sample. We explored the behaviour of 21 chemical
species in the [El/FeI] versus [FeI/H] and [El/FeI] versus age planes, and
compared the results with the latest Galactic chemical evolution models. We
also explored [El/FeI] gradients according to the mean Galactocentric distances
and maximum height above the Galactic plane.
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