A5092405808- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Advanced Thermodynamic Systems and Engines
- Spacecraft and Cryogenic Technologies
Al-Farabi Kazakh National University
2023-2025
Fesenkov Astrophysical Institute
2023-2025
A new spectroscopic study of HR 4049, a post-AGB star in binary system, based on échelle spectra taken between 2019 and 2025 with the 0.81 m telescope Three College Observatory (North Carolina, USA) at resolution R ≈ 12,000 is reported. cross-correlation analysis 73 single C i multiplet 4760–4780 Å range yielded following orbital parameters: period P=428.474±0.002 days, eccentricity e=0.29±0.01, argument periastron ω=242.3∘±0.3∘, epoch T0=2,458,383.2±0.6, heliocentric systemic radial...
In this study, we present refined orbital and fundamental parameters of the Galactic B[e] supergiant binary system HD 327083 using Bayesian Markov Chain Monte Carlo (MCMC) method applied to radial velocities data 327083. We found that is well described by a circular model with mass ratio components q=1.15±0.07. modeled evolutionary history MESA code. Initially, was formed period Porb=108 day, which contained stars 13.00 ±0.05 M⊙ 11.50±0.05 masses. They had relatively slow rotation...
MWC 342 (V1972 Cyg) was discovered nearly 90 years ago as an early-type emission-line star. It among the first hot stars whose strong infrared excess detected in early 1970s. Several mostly short-term photometric and spectroscopic studies resulted contradictory conclusions about nature evolutionary status of 342. has been classified a pre-main-sequence Herbig Be star, evolved suspected binary system, long-period variable Suggestions on secondary component to this B0/B1 primary included cool...
There is growing evidence that many Be stars are parts of binary systems. As the B-type primaries very fast rotators and their spectral lines may be distorted by circumstellar material, it not easy to measure radial velocity directly from lines. It has been shown some binaries exhibit peak intensity variations consisting double-peaked Hα phase-locked with orbital periods. We searched for such in spectra 12 stars, including several known suspected binaries. Our results include confirmation...
Abstract HD 327083 is a binary system that consists of two supergiant components and exhibits the B[e] phenomenon. In this paper, we report determination new set system’s fundamental parameters using combination photometric spectroscopic data as well Gaia EDR3 distance. We found orbital period 107.68 ± 0.02 days. The spectral line content implies effective temperatures ≈7000 K 25,400 1400 K, while variations are consistent with radii ≈106 R ⊙ ≈10 for cool hot components, respectively....
Results are reviewed of a long-term program binary systems observing since 2013 at the 0.81 m telescope Three College Observatory in North Carolina, USA, with an échelle spectrograph medium spectral resolution.The target list includes recognized and suspected normal stars (no lines emission), classical Be stars, objects B[e] phenomenon.The results include refinement orbital elements bright binaries previously observed photographic plates, further evidence for phased-locked peak intensity...
Based on 583 radial velocity (RV) measurements we obtained at the Three College Observatory (TCO, North Carolina, USA) in 2015–2024, (including 396 not previously analyzed from 2020–2024) as well 236 RV data German amateur R. Bücke (2011–2022), calculated pulsation period and amplitude of Cepheid Polaris Aa system (α UMi). The analysis showed that was stable within a few minutes 2020–2024. During this time, increasing reached 1960s level (4–6 km s−1), when its sharp decline began. Since new...