J/MNRAS/437/185 W UMa-type contact binaries ages and masses (Yildiz, 2014)
Origin of W UMa-type contact binaries - age and orbital evolution.
Yildiz M.
<Mon. Not. R. Astron. Soc., 437, 185-194 (2014)>
=2014MNRAS.437..185Y 2014MNRAS.437..185Y
ADC_Keywords: Binaries, eclipsing ; Stars, masses ; Stars, ages
Keywords: binaries: close - binaries: eclipsing - stars: evolution -
stars: interior - stars: late-type
Abstract:
Recently, our understanding of the origin of W UMa-type contact
binaries has become clearer. Initial masses of their components were
successfully estimated by Yildiz and Dogan using a new method mainly
based on observational properties of overluminous secondary
components. In this paper, we continue to discuss the results and make
computations for age and orbital evolution of these binaries. It is
shown that the secondary mass, according to its luminosity, also
successfully predicts the observed radius. While the current mass of
the primary component is determined by initial masses, the current
secondary mass is also a function of initial angular momentum. We
develop methods to compute the age of A- and W-subtype W UMa-type
contact binaries in terms of initial masses and mass according to the
luminosity of the secondaries. Comparisons of our results with the
mean ages from kinematic properties of these binaries and data
pertaining to contact binaries in open and globular clusters have
increased our confidence on this method. The mean ages of both A- and
W-subtype contact binaries are found as 4.4 and 4.6Gyr, respectively.
From kinematic studies, these ages are given as 4.5 and 4.4Gyr,
respectively. We also compute orbital properties of A-subtype contact
binaries at the time of the first overflow. Initial angular momentum
of these binaries is computed by comparing them with the well-known
detached binaries. The angular momentum loss rate derived in the
present study for the detached phase is in very good agreement with
the semi-empirical rates available in the literature. In addition to
the limitations on the initial masses of W UMa-type contact binaries,
it is shown that the initial period of these binaries is less than
about 4.45d.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 118 100 Initial and present properties of the A- and
W-subtype contact binaries
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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/MNRAS/430/2029 : W UMa type contact binaries initial masses (Yildiz+, 2013)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Star name
16 A1 --- Type [A/W] Contact binary subtype
18- 22 F5.3 Rsun a [1.4/5.4] Orbital semimajor axis
24- 28 F5.3 d Per [0.2/0.9] Orbital period
30- 33 F4.2 Msun M1 [0.5/2.8] Mass of primary
35- 38 F4.2 Msun e_M1 rms uncertainty on M1
40- 43 F4.2 Msun M2 [0.1/1.0] Mass of secondary
45- 48 F4.2 Msun e_M2 rms uncertainty on M2
50- 53 F4.2 Msun M1i Initial mass of primary before the mass transfer
55- 58 F4.2 Msun e_M1i rms uncertainty on M1i
60- 63 F4.2 Msun M2i Initial mass of secondary before the mass transfer
65- 68 F4.2 Msun e_M2i rms uncertainty on M2i
70- 73 F4.2 Msun M2L Mass of secondary according to luminosity
75- 78 F4.2 Msun e_M2L rms uncertainty on M2L
80- 84 F5.2 Gyr t [1.2/11.1] Age (see Section 3)
86- 89 F4.2 Gyr e_t rms uncertainty on age
91- 95 F5.2 Gyr tB Age from Bukowiecki et al. (2012IBVS.6021....1B 2012IBVS.6021....1B)
97-101 F5.2 Rsun afof Semimajor axis at first overflow (FOF)
103-106 F4.2 d Pfof Orbital period at FOF
108-112 F5.2 Rsun aD [10/65] Initial orbital semimajor axis
114-118 F5.2 d PerD [2.7/41] Initial orbital period
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History:
* 08-Nov-2014: From electronic version of the journal
* 19-Jan-2015: corrected star name "eta CrA" into "eps CrA" at CDS
(End) Patricia Vannier [CDS] 08-Nov-2014