J/MNRAS/430/2029 Initial masses of W UMa type contact binaries (Yildiz+, 2013)
On the origin of W UMa type contact binaries.
A new method for computation of initial masses.
Yildiz M., Dogan T.
<Mon. Not. R. Astron. Soc., 430, 2029-2038 (2013)>
=2013MNRAS.430.2029Y 2013MNRAS.430.2029Y
ADC_Keywords: Binaries, eclipsing ; Stars, masses
Keywords: binaries: close - binaries: eclipsing - stars: evolution -
stars: interiors - stars: late-type
Abstract:
W UMa type binaries have two defining characteristics. These are (i)
the effective temperatures of both components are very similar, and
(ii) the secondary (currently less massive) component is overluminous
for its current mass. We consider the latter to be an indication of
its mass before the mass transfer event. For these stars, we define a
mass difference (δM) between the mass determined from its
luminosity and the present mass determined from fitting the binary
orbit. We compare the observed values of the mass difference to
stellar models with mass-loss. The range of initial secondary masses
that we find for observed W UMa type binaries is 1.3-2.6M☉. We
discover that the A- and the W-subtype contact binaries have different
ranges of initial secondary masses. Binary systems with an initial
mass higher than 1.8±0.1M☉ become A-subtype while systems with
initial masses lower than this become W-subtype. Only 6 per cent of
systems violate this behaviour. We also obtain the initial masses of
the primaries using the following constraint for the reciprocal of the
initial mass ratio: 0<1/qi<1. The range of initial masses we
find for the primaries is 0.2-1.5M☉, except for two systems.
Finally in comparing our models to observed systems, we find evidence
that the mass transfer process is not conservative. We find that only
34 per cent of the mass from the secondary is transferred to the
primary. The remainder is lost from the system.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 139 100 Fundamental properties of the A- and W-subtype
contact binaries
refs.dat 68 45 References
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See also:
V/119 : Catalogue of field contact binary stars (Pribulla+, 2003)
V/120 : Catalog of early-type contact binaries (Bondarenko+, 1996)
J/PASP/108/332 : Photometric analysis of contact binaries (Lapasset+ 1996)
J/AcA/51/259 : Contact binaries in OGLE-I database (Szymanski+, 2001)
J/A+A/426/1001 : Catalog of contact binary stars (Csizmadia+, 2004)
J/AJ/131/621 : Catalog of 1022 bright contact binary stars (Gettel+, 2006)
J/AJ/131/633 : A ROSAT survey of contact binary stars (Geske+, 2006)
J/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)
J/AcA/56/253 : Period changes of OGLE contact binaries (Kubiak+, 2006)
J/MNRAS/373/1483 : W UMa type and CAB stars dynamical evolution (Eker+, 2006)
J/AJ/134/2353 : Observations of contact binaries (Rucinski+, 2007)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Star Star name
16 A1 --- Type [AW] Contact binary subtype
18- 22 F5.3 d Per [0.2/0.9] Orbital period
24- 27 I4 K T1 Effective temperature of primary
29- 31 I3 K e_T1 ? rms uncertainty on T1
33- 36 I4 K T2 Effective temperature of secondary
38- 40 I3 K e_T2 ? rms uncertainty on T2
42- 45 F4.2 Rsun R1 Radius of primary
47- 50 F4.2 Rsun e_R1 ? rms uncertainty on R1
52- 55 F4.2 Rsun R2 Radius of secondary
57- 60 F4.2 Rsun e_R2 ? rms uncertainty on R2
62- 66 F5.2 Lsun L1 Luminosity of primary
68- 71 F4.2 Lsun e_L1 ? rms uncertainty on L1
73- 76 F4.2 Lsun L2 Luminosity of secondary
78- 81 F4.2 Lsun e_L2 ? rms uncertainty on L2
83- 86 F4.2 Msun M1 Mass of primary
88- 91 F4.2 Msun e_M1 ? rms uncertainty on M1
93- 96 F4.2 Msun M2 Mass of secondary
98-101 F4.2 Msun e_M2 ? rms uncertainty on M2
103-106 F4.2 Msun M2i Initial mass of secondary before the mass
transfer (see Section 5)
108-111 F4.2 Msun e_M2i ? rms uncertainty on M2i
113-116 F4.2 Msun M1i Initial mass of primary before the mass
transfer (see Section 5)
118-121 F4.2 Msun e_M1i ? rms uncertainty on M1i
123-126 F4.2 --- 1/qi Reciprocal of initial mass ratio (M2i/M1i)
128-131 F4.1 Gyr tMS MS lifetime of the secondary component
according to initial mass
133-139 A7 --- Refs References, in refs.dat file
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 45 A22 --- Aut Author's name
46- 68 A23 --- Com Comments
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History:
* 10-Apr-2014: From electronic version of the journal
* 19-Jan-2015: corrected star name "eta CrA" into "eps CrA" (at CDS)
(End) Patricia Vannier [CDS] 10-Apr-2014