J/A+A/690/A201 Detached eclipsing binaries lifetime of starspots (Wang+, 2024)
Lifetime of starspots on detached eclipsing binaries:
Detecting the effects of tides on stellar activity.
Wang J., Pan Y., Fu J., Zong P., Zong W., Cang T., Zhang B., Pan Yu
<Astron. Astrophys. 690, A201 (2024)>
=2024A&A...690A.201W 2024A&A...690A.201W (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Effective temperatures ; Stars, diameters ;
Binaries, orbits
Keywords: stars: activity - binaries: eclipsing - stars: rotation - starspots -
Abstract:
Tidal deformation breaks the axisymmetric structure of stars, and this
may affect stellar activity. This effect has been demonstrated in
theoretical analyses and simulations, but it lacks observational
support. In this paper, we use spot-modulated detached binaries to
study the effect of tides on stellar activity. We show this effect by
analyzing the properties of the spot lifetime, the harmonic decay
timescale, and the orbital parameters.
We aim to explore the differences in spot lifetimes between binaries
and single stars, the main mechanisms of spot decay in binaries, and
the correlation between orbital parameters and spot lifetimes. These
differences will provide clues to the effect of tides on stellar
activity.
We collected data of 311 spot-modulated detached binaries and 3272
single stars. The relative orbital parameters of the binaries were
derived by combining Kepler photometry, stellar atmospheric parameters
from LAMOST DR9 and Gaia DR3, and 2MASS photometry.We then used the
ACF method to obtain the rotational periods, lifetimes, and harmonic
decay timescales. Finally, we analyzed the correlation between the
lifetime of spots and orbital parameters, explored the dominant decay
mechanism of spots, and examined the differences in spots for binaries
and single stars.
The relative lifetime of a starspot is correlated with the sum of the
fractional radii, the orbital eccentricity, and the synchronization
ratio. Longer lifetimes are observed in close, circular, and
synchronous binaries than in the other binaries. The main mechanism
for the decay of star spots in binaries is large-scale convective
motion. However, on close, cool, and fast-rotating binaries,
horizontal diffusion or subphotospheric diffusion are dominant.
Compared to single stars, the median lifetime of a starspot on
binaries was found to be longer. Moreover, this difference decreases
with rotation period. Additionally, it should be noted that spots on
binaries experience increased horizontal or subphotospheric diffusion
at the same rotation period and effective temperature.
According to the observation results, we conclude that the lifetime of
starspots on detached close binaries is affected by tidal
interactions.
Description:
Physical parameters for 318 starspot modula detached eclipsing
binaries. For each binaries, the Kepler ids, the temperature ratio
T2/T1, the sum of the fractional radii (R1+R2)/a, the radius ratio
R2/R1, the inclination , the eccentricity, the mass ratio q, the
orbital period Porb, the effective temperature of primary, the RMS of
starspot, the rotation periods Prot, the lifetime of starspot tau, and
the harmonic decay timescales ratio beta21 are are given.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 93 318 Catalogue of binary parameters
table3.dat 58 311 Catalogue of starspot parameters
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See also:
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC Kepler identifier
10- 14 F5.3 --- T2/T1 Temperature ratio
16- 20 F5.3 --- e_T2/T1 ?=0 Error of temperature ratio (1)
22- 26 F5.3 --- (R1+R2)/a Sum of the fractional radii
28- 33 F6.4 --- e_(R1+R2)/a Error of sum of the fractional radii
35- 38 F4.2 --- R2/R1 Radius ratio
40- 44 F5.3 --- e_R2/R1 Error of radius ratio
46- 50 F5.2 deg incl Inclination
52- 55 F4.2 deg e_incl Error of inclination
57- 61 F5.3 --- ecc Eccentricity
63- 68 F6.4 --- e_ecc Error of eccentricity
70- 74 F5.3 --- q ? Mass ratio
76- 84 F9.6 d Porb Orbital period from KEBC (2)
86- 89 I4 K Teff Effective temperature of primary
91- 93 I3 K e_Teff Error of effective temperature
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Note (1): A zero indicates that the error is not specified.
Note (2): KEBC is Kepler Eclipsing Binary Catalog.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC Kepler identifier
10- 16 F7.5 --- RMS RMS of straspot
18- 26 F9.4 d tau Lifetime of starspot
27- 33 F7.4 d e_tau Error of lifetime of starspot
35- 43 F9.6 d Prot Rotation period
45- 52 E8.6 d e_Prot Error of rotation period
54- 58 F5.2 --- beta21 ? Harmonic decay timescales ratio
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Acknowledgements:
Jiaxin Wang, wangjx(at)cqupt.edu.cn
(End) Patricia Vannier [CDS] 14-Sep-2024