J/AJ/155/133 Radial velocities of the semi-detached Algol W UMi (Park+, 2018)
Absolute dimensions and evolutionary status of the semi-detached Algol W Ursae
Minoris.
Park J.-H., Hong K., Koo J.-R., Lee J.W., Kim C.-H.
<Astron. J., 155, 133 (2018)>
=2018AJ....155..133P 2018AJ....155..133P
ADC_Keywords: Binaries, eclipsing; Spectra, optical; Radial velocities
Keywords: binaries: eclipsing ; binaries: spectroscopic ; stars: evolution ;
stars: fundamental parameters ; stars: individual (W UMi)
Abstract:
Double-lined eclipsing binaries allow accurate and direct
determination of fundamental parameters such as mass and radius for
each component, and they provide important constraints on the stellar
structure and evolution models. In this study, we aim to determine a
unique set of binary parameters for the Algol system W UMi and to
examine its evolutionary status. New high-resolution time-series
spectroscopic observations were carried out during 14 nights from 2008
April to 2011 March, and a total of 37 spectra were obtained using the
Bohyunsan Optical Echelle Spectrograph. We measured the radial
velocities (RVs) for both components, and the effective temperature of
the primary star was found to be Teff,1=9310±90K by a comparison
of the observed spectra and the Kurucz models. The physical parameters
of W UMi were derived by an analysis of our RV data together with the
multi-band light curves of Devinney et al. The individual masses,
radii, and luminosities of both components are M1=3.68±0.10M☉
and M2=1.47±0.04M☉, R1=3.88±0.03R☉ and
R2=3.13±0.03R☉, and L1=102±1L☉ and L2=7.3±0.1L☉,
respectively. A comparison of these parameters with theoretical
stellar models showed that the primary component lies in the
main-sequence band, while the less massive secondary is noticeably
evolved. The results indicate that the initially more massive star
became the present secondary by losing most of its own mass via mass
transfer to the companion (present primary).
Description:
New spectroscopic observations were made on 14 nights between 2008
April and 2011 March using the 1.8m telescope at the Bohyunsan Optical
Astronomy Observatory (BOAO). We obtained a total of 37 spectra using
the Bohyunsan Optical Echelle Spectrograph (BOES) attached to the
telescope, which is designed to cover the wavelength region of
3600-10200Å (R∼30000).
Objects:
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RA (ICRS) DE Designation(s) (Per)
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16 08 27.27 +86 11 59.6 W UMi = V* W UMi (P=1.701158)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 37 37 Radial velocities of W UMi
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See also:
J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)
J/MNRAS/363/529 : uvby, UBV and radial velocity of WW Aur (Southworth+, 2005)
J/MNRAS/373/435 : Angular momentum evolution of Algol bin. (Ibanoglu+, 2006)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 d HJD [4568/5633.3] Heliocentric Julian Date;
HJD-2450000
11- 15 F5.3 --- Phase [0.003/1] Phase
17- 22 F6.1 km/s V1 [-106.1/73.6] Radial velocity for the primary
component
24- 26 F3.1 km/s e_V1 [0.8/5.1] V1 uncertainty (σ)
28- 33 F6.1 km/s V2 [-222.2/197.7]? Radial velocity for the secondary
component
35- 37 F3.1 km/s e_V2 [0.9/8.8]? V2 uncertainty (σ)
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 29-Jan-2020