TY - JOUR
T1 - First detailed study of two eccentric eclipsing binaries
T2 - TYC 5378-1590-1 and TYC 8378-252-1
AU - Zasche, P.
AU - Sürgit, D.
AU - Erdem, A.
AU - Engelbrecht, C. A.
AU - Marang, F.
N1 - Publisher Copyright:
© 2023 Authors. All rights reserved.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - Aims. The analysis of combined photometry and spectroscopy of eccentric eclipsing binary systems facilitates the derivation of very precise values for a large ensemble of physical parameters of the component stars and their orbits, thereby providing stringent tests of theories of stellar structure and evolution. In this paper two eccentric eclipsing binary systems, TYC 5378-1590-1 and TYC 8378-252-1, are studied in detail for the first time. Methods. Radial velocities were obtained using cross-correlation methods applied to mid-resolution spectra covering almost the entire orbital phase domains of these two systems. TESS photometry was used for the analysis of TYC 5378-1590-1, whereas ASAS-SN photometry was used for the analysis of TYC 8378-252-1. Results. We obtained the first precise derivation of the physical parameters of these systems. Both systems display moderately eccentric orbits (e∼ 0.3 and 0.2) with periods of 3.73235 and 2.87769 days, respectively. The apsidal motion is very slow, with a duration of several centuries for both systems. We present two models for the apsidal motion of TYC 5378-1590-1. The internal structure constant derived from observations for TYC 8378-252-1 is approximately 11% lower than theoretical predictions. We discuss possible reasons for this discrepancy. Our analysis indicates that the components of both systems are on the main sequence. The components of TYC 5378-1590-1 are relatively young stars (age ∼600 Myr) close to the ZAMS, whereas the components of TYC 8378-252-1 are relatively old stars (age ∼4 Gyr) close to the TAMS. Our finding that the circularization timescale for TYC 5378-1590-1 is ∼200 times longer than its evolutionary age is compatible with circularization theory; however, our finding that the evolutionary age of TYC 8378-252-1 is approximately ten times longer than the circulation age, while its orbital eccentricity is quite high (e∼ 0.2), challenges the present theories of circularization.
AB - Aims. The analysis of combined photometry and spectroscopy of eccentric eclipsing binary systems facilitates the derivation of very precise values for a large ensemble of physical parameters of the component stars and their orbits, thereby providing stringent tests of theories of stellar structure and evolution. In this paper two eccentric eclipsing binary systems, TYC 5378-1590-1 and TYC 8378-252-1, are studied in detail for the first time. Methods. Radial velocities were obtained using cross-correlation methods applied to mid-resolution spectra covering almost the entire orbital phase domains of these two systems. TESS photometry was used for the analysis of TYC 5378-1590-1, whereas ASAS-SN photometry was used for the analysis of TYC 8378-252-1. Results. We obtained the first precise derivation of the physical parameters of these systems. Both systems display moderately eccentric orbits (e∼ 0.3 and 0.2) with periods of 3.73235 and 2.87769 days, respectively. The apsidal motion is very slow, with a duration of several centuries for both systems. We present two models for the apsidal motion of TYC 5378-1590-1. The internal structure constant derived from observations for TYC 8378-252-1 is approximately 11% lower than theoretical predictions. We discuss possible reasons for this discrepancy. Our analysis indicates that the components of both systems are on the main sequence. The components of TYC 5378-1590-1 are relatively young stars (age ∼600 Myr) close to the ZAMS, whereas the components of TYC 8378-252-1 are relatively old stars (age ∼4 Gyr) close to the TAMS. Our finding that the circularization timescale for TYC 5378-1590-1 is ∼200 times longer than its evolutionary age is compatible with circularization theory; however, our finding that the evolutionary age of TYC 8378-252-1 is approximately ten times longer than the circulation age, while its orbital eccentricity is quite high (e∼ 0.2), challenges the present theories of circularization.
KW - Binaries: eclipsing
KW - Binaries: spectroscopic
KW - Stars: fundamental parameters
UR - http://www.scopus.com/inward/record.url?scp=85147660371&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202245386
DO - 10.1051/0004-6361/202245386
M3 - Article
AN - SCOPUS:85147660371
SN - 0004-6361
VL - 670
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A39
ER -