HR 4049: A Spectroscopic Analysis of a Post-AGB Object

Nurmakhametova S.T. Vaidman N.L. Miroshnichenko A.S. Khokhlov A.A. Agishev A.T. Yermekbayev B.S. Danford S. Aarnio A.N.
April 2025 Multidisciplinary Digital Publishing Institute (MDPI)

Galaxies
2025 #13 Issue 2

A new spectroscopic study of HR 4049, a post-AGB star in a binary system, based on échelle spectra taken between 2019 and 2025 with the 0.81 m telescope of the Three College Observatory (North Carolina, USA) at a resolution of R ≈ 12,000 is reported. A cross-correlation analysis of 73 spectra of a single C i multiplet in the 4760–4780 Å range yielded the following orbital parameters: the orbital period (Formula presented.) days, eccentricity (Formula presented.), argument of periastron (Formula presented.), epoch of periastron (Formula presented.), heliocentric systemic radial velocity (Formula presented.) km s⁻¹, and semi-amplitude of the radial velocity curve (Formula presented.) km s⁻¹. Phase-dependent variations of the Hα line profile indicate dynamic processes in the circumstellar environment. The luminosity of HR 4049 was refined using the Gaia EDR3 parallax ((Formula presented.) mas), corresponding to a distance of (Formula presented.) pc, and the average visual magnitude in the brightest state ((Formula presented.) mag). The derived luminosity, (Formula presented.), suggests an initial mass of 3.0–4.0 (Formula presented.). Analysis of the mass function and most probable orbital inclinations (60°–75°) leads to current masses of (Formula presented.) for the primary and (Formula presented.) – (Formula presented.) for the secondary component. The results confirm the system’s long-term orbital stability and provide further insights for future research into the nature of post-AGB binaries.

binary stars , circumstellar matter , emission-line stars , post-AGB stars , spectroscopy

Text of the article Перейти на текст статьи

Faculty of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi Ave., 71, Almaty, 050040, Kazakhstan
Fesenkov Astrophysical Institute, Observatory, 23, Almaty, 050020, Kazakhstan
Department of Physics and Astronomy, University of North Carolina—Greensboro, Greensboro, 27402, NC, United States

Faculty of Physics and Technology
Fesenkov Astrophysical Institute
Department of Physics and Astronomy

10 лет помогаем публиковать статьи Международный издатель

Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026