Long-period double-lined eclipsing binaries: the system V454 Aur with the secondary eclipse caused by the occultation of the hotter component

Abstract

We present the results of our study of the long-period eclipsing binary star \Aur. The results are based on spectroscopic data obtained with the UFES échelle spectrograph and photometric observations from TESS. The derived radial velocity curve is based on 17 spectra obtained between 2021 and 2023, covering all orbital phases of this binary system. The orbital period determined from TESS data, $P=27.019803\pm 0.000003$ days, agrees within uncertainties with the period established in previous studies. The model constructed for the TESS photometric light curve achieves a precision of 0.01\%. The effective temperatures of both components, as well as the system metallicity, were directly derived from the spectra and are $T_{\mathrm{eff},\mathrm{A}}=6250\pm 50$\,K, $T_{\mathrm{eff},\mathrm{B}}=5855\pm 50$\,K, and $[Fe/H]=-0.10\pm 0.08$, respectively. Our analysis of the photometric and spectroscopic data allowed us to directly compute the luminosities of the components, $L_A=1.82L_{\odot }$ and $L_B=1.07L_{\odot }$, their radii, $R_A=1.15R_{\odot }$ and $R_B=1.00R_{\odot }$, and their masses, $M_A=1.137M_{\odot }$ and $M_B=1.023M_{\odot }$, with uncertainties below 1\%. Comparison with evolutionary tracks indicates that the system's age is $1.18\pm 0.10$\,Gyr, and both components are still on the main sequence. The \Aur\ system is particularly interesting due to the partial eclipse of the primary component, which results in the ``inversion'' of the primary and secondary minima in the photometric light curve.

Published by RAA, 15 pages, 9 figures, 5 tables

References in corpus (22)

• The Gaia mission
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Gaia Data Release 3: Summary of the content and survey properties
• Validation of the new Hipparcos reduction
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Accurate masses and radii of normal stars: modern results and applications
• New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
• The Geneva-Copenhagen Survey of the Solar neighbourhood III. Improved distances, ages, and kinematics
• A new library of theoretical stellar spectra with scaled-solar and alpha-enhanced mixtures
• MN48: a new Galactic bona fide luminous blue variable revealed by Spitzer and SALT
• Identical or fraternal twins? : The chemical homogeneity of wide binaries from Gaia DR2
• The Araucaria Project: High-precision orbital parallax and masses of eclipsing binaries from infrared interferometry
• A new family of non--linear filters for background subtraction of wide--field surveys
• Kinematics and Multi Band Period-Luminosity-Metallicity Relation of RR Lyrae Stars via Statistical Parallax
• ELISa: A new tool for fast modelling of eclipsing binaries
• Long-period eclipsing binaries: towards the true mass-luminosity relation. I. The test sample, observations and data analysis
• Long-period eclipsing binaries: towards the true mass-luminosity relation. II. Absolute parameters of the NN Del system
• SALT observations of the supernova remnant MCSNR J0127-7332 and its associated Be X-ray binary SXP 1062 in the SMC
• Searching For Wide Binary Stars with Non-coeval Components in the Southern Sky
• SALT spectroscopy of the HMXB associated with the LMC supernova remnant MCSNR\,J0513$-$6724