J/ApJS/277/51 ASAS-SN contact binaries param. from neural network (Li+, 2025)
Physical parameters of 12201 ASAS-SN contact binaries determined by a Neural
Network.
Li K., Wang L.-H.
<Astrophys. J. Suppl. Ser., 277, 51 (2025)>
=2025ApJS..277...51L 2025ApJS..277...51L
ADC_Keywords: Binaries, eclipsing; Stars, variable; Stars, diameters
Keywords: Astronomy data analysis ; Eclipsing binary stars ;
Contact binary stars ; Fundamental parameters of stars
Abstract:
In the era of astronomical big data, more than one million contact
binaries have been discovered. Traditional approaches of light-curve
analysis are inadequate for investigating such an extensive number of
systems. This paper builds on prior research to present an advanced
neural network model combined with the Markov Chain Monte Carlo
algorithm and including spot parameters. This model was applied to
12,785 contact binaries selected from All-Sky Automated Survey for
Supernovae. By removing those with a goodness of fit less than 0.8, we
obtained the physical parameters of 12,201 contact binaries. Among
these binaries, 4332 are A-subtype systems, while 7869 are W-type
systems, and 1594 systems have mass ratios larger than 0.72 (H-subtype
systems). A statistical study of the physical parameters was carried
out, and we found that there are two peaks in the mass-ratio
distribution and that the probability of the presence of spots is
about 50%. In addition, the differences in flux between the two light
maxima are from -0.1 to 0.1. As the orbital period and the temperature
of the primary component decrease, the difference between the two
light maxima becomes more pronounced. Based on the relationships
between the transfer parameter and luminosity ratio, as well as
between the luminosity ratio and mass ratio, we found that A-, W-, and
H-type contact binaries are distributed in distinct regions.
Description:
The ASAS-SN Catalog of Variable Stars (Shappee+ 2014, J/ApJ/788/48;
Jayasinghe+ 2019MNRAS.485..961J 2019MNRAS.485..961J) has identified 78,503 EW-type
eclipsing binaries. We used two criteria to select samples to analyze.
First, the class probability should be no less than 0.99; second, the
Lafler-Kinman string length statistic should be smaller than 0.1. We
downloaded the flux LCs of the resulting 12,785 targets, and removed
the data points below the 1st percentile and above the 99th
percentile.
Based on our six neural network (NN) models, we used the Markov Chain
Monte Carlo (MCMC) algorithm to determine the physical parameters of
the contact binaries.
We calculated the physical parameters using MCMC twice. Physical
parameters for a total of 12,201 contact binaries were obtained.
See Section 4.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 190 12201 Physical parameters of the 12201 ASAS-SN contact
binaries
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See also:
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)
J/A+A/426/1001 : Catalog of contact binary stars (Csizmadia+, 2004)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/ApJ/859/140 : Multi-band magnitudes for W UMa EB* candidates (Chen+, 2018)
J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)
J/AJ/159/189 : Eclipse timings for 9 contact binaries (Li+, 2020)
J/ApJS/247/50 : Late-type contact binaries in CSS DR1 (Sun+, 2020)
J/AJ/164/202 : Extremely Low Mass Ratio Contact Binaries I. (Li+, 2022)
J/ApJS/258/16 : TESS Eclipsing Binary stars. I. Sectors 1-26 (Prsa+, 2022)
J/A+A/692/L4 : The lowest mass ratio contact binary (Li+, 2024)
J/ApJS/271/32 : ASAS-SN eclipsing contact binaries with Gaia DR3 (Li+, 2024)
J/ApJS/272/31 : RVels & metallicities of RR Lyrae from LAMOST (Wang+, 2024)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- --- [ASASSN-V -]
10- 28 A19 --- ASASSN-V ASAS-SN identifier (JHHMMSS.ss+DDMMSS.s)
30- 36 F7.3 deg RAdeg Right ascension in decimal degrees (J2000)
38- 44 F7.3 deg DEdeg Declination in decimal degrees (J2000)
46- 52 F7.5 d Per [0.2/2.5] Orbital period
54- 65 F12.4 d Min.I Time of minimum light; Heliocentric Julian date
67- 72 F6.4 d e_Min.I [0.0002/0.03] Uncertainty in Min.I
74- 76 A3 --- Type Contact binary system subtype (1)
78- 82 I5 K T1 [3802/18087] Temperature of primary component
84- 88 F5.3 --- q [0.036/1] Mass ratio of the two components
90- 94 F5.3 --- e_q [0.001/0.82] Uncertainty in q
96- 101 F6.3 deg i [31.3/90] Orbital inclination
103- 108 F6.3 deg e_i [0.04/33.3] Uncertainty in i
110- 114 F5.3 --- T2/T1 [0.7/1.2] Temperature ratio of the two components
116- 120 F5.3 --- e_T2/T1 [0/0.3] Uncertainty in T2/T1
122- 126 F5.3 --- f [0/1] Fill-out factor
128- 132 F5.3 --- e_f [0/0.8] Uncertainty in f
134- 138 F5.3 --- l3 [0/0.6] Third light ratio
140- 144 F5.3 --- e_l3 [0/0.5] Uncertainty in l3
146- 150 F5.3 --- Ts [0/1.0] Relative temperature of spot
152- 156 F5.3 --- e_Ts [0/0.2] Uncertainty in Ts
158- 160 I3 deg long [0/270] Longitude of spot
162- 166 F5.3 --- L2/L1 [0.029/2.1] Luminosity ratio between the two
components
168- 172 F5.3 --- r1 [0.38/0.7] Relative radius of primary component
174- 178 F5.3 --- r2 [0.15/0.5] Relative radius of secondary component
180- 184 F5.3 --- Omega [1.7/3.8] Surface potential Ω
186- 190 F5.3 --- R2 [0.8/1] Goodness of fit R2
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Note (1): Subtype as follows:
A = A-subtype system (3484 occurrences)
W = W-subtype system (7123 occurrences)
H/A = (848 occurrences)
H/W = (746 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-Jan-2026