English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We describe the procedure to determine effective temperatures, rotational velocities, microturbulent velocities and chemical abundances in the atmospheres of Sun‐like stars. We use independent determinations of iron abundances using the fits to the observed Fe  i  and Fe  ii  atomic absorption lines. We choose the best solution from the fits to these spectral features for the model atmosphere that provides the best confidence in the determined log  N (Fe),  V  t  and  v  sin  i . Computations were performed in the framework of local thermodynamic equilibrium. Blending effects were accounted for explicitly. First, we compute the abundance of iron for a set of adopted microturbulent velocities. In some cases, a few points of log  N (Fe  i ) = log  N (Fe  ii ) can be found. To determine the most self‐consistent effective temperature and microturbulent velocity in any star’s atmosphere, we used an additional constraint where we minimize the dependence of the derived abundances of Fe  i  and Fe  ii  on the excitation potential of the corresponding lines. Using this procedure we analyse the spectra of the Sun and two well‐known solar‐type stars, HD 1835 and HD 10700, to determine their abundances, microturbulent velocity and rotational velocity. Our approach allows us to determine self‐consistent values for the effective temperatures, abundances,  V  t  and  v  sin  i . For the Sun, we obtain the best agreement for a model atmosphere of  T  eff /log  g /[Fe/H] = 5777/4.44/0.0, iron abundances and microturbulent velocities of log  N (Fe) = 4.44,  V  t = 0.75 km s −1 , for the Fe  i  lines, and log  N (Fe) =−4.47 and  V  t = 1.5 km s −1  for the Fe  ii  lines. Furthermore, abundances of other elements obtained from the fits of their absorption features agree well enough (±0.1 dex) with the known values for the Sun. We determined a rotational velocity of  v  sin  i = 1.6 ± 0.3 km s −1  for the spectrum of the Sun as a star. For HD 1835, the self‐consistent solution for Fe  i  and Fe  ii  lines log  N (Fe) =+0.2 was obtained with a model atmosphere of 5807/4.47/+0.2 and microturbulent velocity of  V  t = 0.75 km s −1 , and leads to  v  sin  i = 7.2 ± 0.5 km s −1 . For HD 10700, the self‐consistent solution log  N (Fe) =−4.93 was obtained using a model atmosphere of 5383/4.59/−0.6 and microturbulent velocity of  V  t = 0.5 km s −1 . The Fe  i  and Fe  ii  lines give rise to a  v  sin  i = 2.4 ± 0.4 km s −1 . Using  T  eff  found from the ionization equilibrium parameters for all three stars, we found abundances of a number of other elements: Ti, Ni, Ca, Si and Cr. We show that uncertainties in the adopted values of  T  eff  of 100 K and  V  t  of 0.5 km s −1  change the abundances of elements up to 0.1 and 0.2 dex, respectively. Galactic abundance variations can generally be larger than this measurement precision and therefore we can study abundance variations throughout the Galaxy.

Effective temperatures, rotational velocities, microturbulent velocities and abundances in the atmospheres of the Sun, HD 1835 and HD 10700 ★