J/A+A/670/A39 TYC 5378-1590-1 and TYC 8378-252-1 RV curves (Zasche+, 2023)
First detailed study of two eccentric eclipsing binaries:
TYC 5378-1590-1 and TYC 8378-252-1.
Zasche P., Surgit D., Erdem A., Engelbrecht C.A., Marang F.
<Astron. Astrophys. 670, A39 (2023)>
=2023A&A...670A..39Z 2023A&A...670A..39Z (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Binaries, spectroscopic ;
Radial velocities ; Optical
Keywords: binaries: eclipsing - binaries: spectroscopic -
stars: fundamental parameters
Abstract:
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.
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.
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 ∼600Myr) close to the ZAMS, whereas
the components of TYC 8378-252-1 are relatively old stars (age ∼4Gyr)
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.
Description:
The data for TYC 5378-1590-1 and TYC 8378-252-1 were obtained partly
from dedicated observational campaigns on these stars. This is
specifically true of the spectroscopic data, where several dozen
radial velocity observations were obtained during multi-year campaigns
using the Cassegrain-mounted spectrograph on the 1.9m telescope at
the South African Astronomical Observatory (SAAO).
Objects:
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RA (2000) DE Designation(s) (Per (d))
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06 45 43.95 -08 50 35.4 TYC 5378-1590-1 = TIC 120023539 (3.7323493)
18 59 51.28 -47 11 47.5 TYC 8378-252-1 = TIC 143603179 (2.8776874)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
t5378_rv.dat 48 51 Radial velocity measurements, with standard
errors, of the components of TYC 5378-1590-1
(table A1)
t8378_rv.dat 48 56 Radial velocity measurements, with standard
errors, of the components of TYC 8378-252-1
(table A2)
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Byte-by-byte Description of file: t5378_rv.dat t8378_rv.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- No No of the observation
5- 16 F12.4 d HJD Heliocentric Julian Date of observation
20- 25 F6.2 km/s RV1 ? Radial velocity of primary component
28- 32 F5.2 km/s e_RV1 ? Radial velocity error of primary component
34- 41 F8.2 km/s RV2 ? Radial velocity of secondary component
44- 48 F5.2 km/s e_RV2 ? Radial velocity error of secondary component
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Acknowledgements:
Petr Zasche, zasche(at)sirrah.troja.mff.cuni.cz
(End) Patricia Vannier [CDS] 02-Dec-2022