J/MNRAS/363/529 uvby, UBV and radial velocity of WW Aur (Southworth+, 2005)
Absolute dimensions of detached eclipsing binaries -
I. The metallic-lined system WW Aurigae.
Southworth J., Smalley B., Maxted P.F.L., Claret A., Etzel P.B.
<Mon. Not. R. Astron. Soc., 363, 529-542 (2005)>
=2005MNRAS.363..529S 2005MNRAS.363..529S
ADC_Keywords: Binaries, eclipsing ; Photometry, uvby ; Photometry, UBV ;
Radial velocities
Keywords: stars: binaries: eclipsing - stars: fundamental parameters -
stars: binaries: spectroscopic - stars: early-type -
stars: chemically peculiar
Abstract:
WW Aurigae is a detached eclipsing binary composed of two metallic-
lined A-type stars orbiting each other every 2.5 days. We have
determined the masses and radii of both components to accuracies of
0.4% and 0.6%, respectively. From a cross-correlation analysis of
high-resolution spectra we find masses of 1.964±0.007M☉ for
the primary star and 1.814±0.007M☉ for the secondary star.
From an analysis of photoelectric uvby and UBV light curves we find
the radii of the stars to be 1.927±0.011R☉ and
1.841±0.011R☉, where the uncertainties have been calculated
using a Monte Carlo algorithm. Fundamental effective temperatures of
the two stars have been derived, using the Hipparcos parallax of WW
Aur and published ultraviolet, optical and infrared fluxes, and are
7960±420 and 7670±410K. The masses, radii and effective
temperatures of WW Aur are only matched by theoretical evolutionary
models for a fractional initial metal abundance, Z, of approximately
0.06 and an age of roughly 90Myr. This seems to be the highest metal
abundance inferred for a well-studied detached eclipsing binary, but
we find no evidence that it is related to the metallic-lined nature of
the stars. The circular orbit of WW Aur is in conflict with the
circularization timescales of both the Tassoul and the Zahn tidal
theories and we suggest that this is due to pre-main-sequence
evolution or the presence of a circular orbit when the stars were
formed.
Description:
Observational data and results are presented for the A-type detached
eclipsing binary star system WW Aurigae. The known times of minimum
light of the system are given. Stromgren uvby photoelectric light
curves, with about 950 measurements in each passband, are given. These
are originally from Etzel (1975, Masters Thesis, San Diego State
University, unpublished). Johnson UBV photoelectric light curves, with
about 1000 measurements in each passband, are given. These were
obtained from Kiyokawa & Kitamura (1975AnTok..15..117K 1975AnTok..15..117K) using optical
character recognition software and were included here for convenience.
We also give the radial velocities of the two stars measured using
TODCOR (Zucker & Mazeh, 1994ApJ...420..806Z 1994ApJ...420..806Z) with template spectra of
HD 39945 (for the primary component of WW Aur) and HD 32115 (for the
secondary component).
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
06 32 27.2 32 27 17 WW Aur = HR 2372
-----------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
minima.dat 12 69 Times of minimum light from the literature
ustro.dat 25 981 Stroemgren u differential photoelectric photometry
(from Etzel, 1975, Masters Thesis)
bstro.dat 25 902 Stroemgren b differential photoelectric photometry
(from Etzel, 1975, Masters Thesis)
ystro.dat 25 903 Stroemgren y differential photoelectric photometry
(from Etzel, 1975, Masters Thesis)
vstro.dat 25 962 Stroemgren v differential photoelectric photometry
(from Etzel, 1975, Masters Thesis)
ujohn.dat 23 999 Johnson U differential photoelectric photometry
(Kiyokawa & Kitamura, 1975AnTok..15..117K 1975AnTok..15..117K)
bjohn.dat 23 980 Johnson B differential photoelectric photometry
(Kiyokawa & Kitamura, 1975AnTok..15..117K 1975AnTok..15..117K)
vjohn.dat 23 1058 Johnson V differential photoelectric photometry
(Kiyokawa & Kitamura, 1975AnTok..15..117K 1975AnTok..15..117K)
rv.dat 26 58 Radial velocities of both components of WW Aur
(Kiyokawa & Kitamura, 1975AnTok..15..117K 1975AnTok..15..117K)
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Byte-by-byte Description of file: minima.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian Date times of minimum light
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Byte-by-byte Description of file: [uvby]stro.dat [ubv]john.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD HJD of observation
15 A1 --- Band [uvbyUBV] Photometric band
17- 25 F9.5 mag dmag Observed differential magnitude
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Byte-by-byte Description of file: rv.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD HJD of observation
13- 19 F7.1 km/s RV(A) Measured radial velocity of primary star
20- 26 F7.1 km/s RV(B) Measured radial velocity of secondary star
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Acknowledgements: John Southworth, jkt(at)astro.keele.ac.uk
(End) John Southworth [Keele, U.K], Patricia Vannier [CDS] 20-Oct-2005