76 citations · 310 across the 18 of their papers we have counts for
18 papers
Study of the Cet Binary with Speckle Interferometric, Photometric and Spectroscopic Techniques
V. V. Dyachenko, I. A. Yakunin, R. M. Bayazitov +8
We present a refined speckle-interferometric orbit of a binary system Cet, with the main component studied based on the analysis of photometric and spectroscopic data, obtained…
Using Molecular Lines to Determine Carbon and Nitrogen Abundances in the Atmospheres of Cool Stars
T. Ryabchikova, N. Piskunov, Y. Pakhomov
Simultaneous analysis of the C_2 and CN molecular bands in the 5100-5200 and 7930-8100A spectral regions is a promising alternative for the accurate determination of the carbon (C)…
Hyperfine Splitting in the VALD Database of Spectral-line Parameters
Yu. V. Pakhomov, T. A. Ryabchikova, N. E. Piskunov
The Vienna Atomic Line Database (VALD) has been supplemented with new data and new functionality -- the possibility of taking into account the effect of hyperfine splitting (HFS) o…
TYC 8606-2025-1: a mild barium star surrounded by the ejecta of a very late thermal pulse
V. V. Gvaramadze, Yu. V. Pakhomov, A. Y. Kniazev +4
We report the discovery of a spiral-like nebula with the Wide-field Infrared Survey Explorer (WISE) and the results of optical spectroscopy of its associated star TYC 8606-2025-1 w…
Contribution of type Ia supernovae to the chemical enrichment of the ultra-faint dwarf galaxy Bootes I
Yu. V. Pakhomov, L. I. Mashonkina, T. M. Sitnova +1
For three stars in the ultra-faint dwarf (UFD) galaxy Bootes I we have determined the atmospheric parameters, performed a new reduction of high-resolution spectra from the Subaru a…
Cool spots on the surface of the active giant PZ Mon
Yu. V. Pakhomov, V. I. Shenavrin, N. I. Bondar' +4
Based on the multiband (BVRIJHKL) photometric observations of the active red giant PZ Mon performed for the first time in the winter season of 2017-2018, we have determined the mai…
Spotted surface structure of the active giant PZ Mon
Yu. V. Pakhomov, K. A. Antonyuk, N. I. Bondar' +3
Based on our photometric observations in 2015-2016 and archival photometric data for the active red giant PZ Mon, we have found the main characteristics of the stellar surface: the…
Triple system HD 201433 with a SPB star component seen by BRITE-Constellation: Pulsation, differential rotation, and angular momentum transfer
T. Kallinger, W. W. Weiss, P. G. Beck +17
Stellar rotation affects the transport of chemical elements and angular momentum and is therefore a key process during stellar evolution, which is still not fully understood. This…
Influence of departures from LTE on calcium, titanium, and iron abundance determinations in cool giants of different metallicities
Lyudmila Mashonkina, Tatyana Sitnova, Yuri Pakhomov
Non-local thermodynamic equilibrium (non-LTE) line formation for Ca I-Ca II, Ti I-Ti II, and Fe I-Fe II is considered in model atmospheres of giant stars with an effective temperat…
Accuracy of atmospheric parameters of FGK dwarfs determined by spectrum fitting
T. Ryabchikova, N. Piskunov, Yu. Pakhomov +6
We performed extensive tests of the accuracy of atmospheric parameter determination for FGK stars based on the spectrum fitting procedure Spectroscopy Made Easy (SME). Our stellar…
Overabundance of s-process elements in the atmosphere of the active red giant
Yu. V. Pakhomov
Based on high-resolution (R=60000) spectra taken with the NES spectrograph (the 6-m BTA telescope, the Special Astrophysical Observatory of the Russian Academy of Science), we have…
The list of tantalum lines for wavelengths calibration of the Hamilton echelle-spectrograph
Yu. V. Pakhomov
We present solution of the problem of wavelength calibration for Hamilton Echelle spectrograph using hollow cathode lamp, which was operated at Lick Observatory Shane telescope bef…
PZ Mon is a new synchronous binary with low mass ratio
Y. V. Pakhomov, N. A. Gorynya
Analysis of new radial velocity measurements of the active giant PZ Mon is presented. Only in 2015 was reported that PZ Mon may be classified as RS CVn giant. At the same time was…
Non-LTE Sodium Abundance in Galactic Thick- and Thin-Disk Red Giants
S. A. Alexeeva, Yu. V. Pakhomov, L. I. Mashonkina
We evaluate non-local thermodynamical equilibrium (non-LTE) line formation for neutral sodium in model atmospheres of the 79 red giants using the model atom that incorporates the b…
Chemical Composition of the Atmospheres of Red Giants with High Space Velocities
Yu. V. Pakhomov
The results of a comparative analysis of the elemental abundances in the atmospheres of 14 red giants with high Galactic space velocities are presented. For almost all of the chemi…
Sodium in the Atmospheres of Thick-Disk Red Giants
Yu. V. Pakhomov
The parameters and elemental abundances of atmospheres for ten thick-disk red giants was determined from high-resolution spectra by the method of model stellar atmospheres. The res…
Wavelength calibration of the Hamilton echelle spectrograph
Yu. V. Pakhomov, G. Zhao
We present the wavelength calibration of the Hamilton echelle spectrograph (the Lick observatory). The main problem of the calibration arises from the fact that thorium lines are a…
Search for broad absorption lines in spectra of stars in the field of supernova remnant RX J0852.0-4622 (Vela Jr.)
A. F. Iyudin, Yu. V. Pakhomov, N. N. Chugai +4
Supernova remnant (SNR) RX J0852.0-4622 is one of the youngest and is most likely the closest among known galactic supernova remnants (SNRs). It was detected in X-rays, the 44Ti ga…