Model atmospheres of red giants

A detailed study of lithium in 107 CHEPS dwarf stars

“…∆ NLTE values are lower for the other stars. As was shown by Pavlenko (1994) for the case of G-K stars with solar abundances, the significance of NLTE effects depends upon the line strength. Weak Li lines are affected by the overionization processes, therefore, their departure corrections tend to be positive (∆ NLTE > 0), whereas lines of intermediate strength form in atmospheric layers where the source function S ν (τ NLTE ≈ 1) is less than the LTE Plank function B ν (τ LTE ≈ 1), and NLTE cores of the resonance doublet become stronger than the LTE ones.…”

“…We used the model atmospheres computed by Ivanyuk et al (2017) using SAM12 programme (Pavlenko 2003). Model atmospheres, synthetic spectra were computed for the same set of input parameters.…”

“…To carry out the NLTE analysis for a 20-level Li atom model, we followed the procedure described in Pavlenko (1994) and Pavlenko & Magazzu (1996). We used the same opacity source list and ionisation-dissociation approach as for the model atmospheres and synthetic spectra procedures, see Ivanyuk et al (2017).…”

“…LTE model atmospheres and synthetic spectra were computed with the SAM12 and WITA6 programmes, respectively (see Pavlenko 1997Pavlenko , 2003. The fine details of our procedure for the determination of abundances assuming LTE are described in Ivanyuk et al (2017).…”

Infrared Mn i laboratory oscillator strengths for the study of late type stars and ultracool dwarfs

“…We have computed the synthetic spectra of late-type stars and brown dwarfs using the WITA6 programme (Pavlenko 2000). The model atmospheres for the Sun (spectral classification = G2V, T eff / log(g) = 5770/4.44, and abundances from Gurtovenko & Kostik 1989), and Arcturus (K2III, 4300/1.5, and abundances from Peterson et al 1993) have been computed with ATLAS12 (Kurucz 1993;Pavlenko 2003).…”