The Subdwarf Eclipsing Binary LB3459 (AA Dor)

A review was presented of the currently available observational data on this evolved system, namely, uvby photometry (Kilkenny et al. 1978; paper II) radial velocities (Kilkenny et al. 1981; paper III) and a non-LTE atmosphere analysis of the primary component (Kudritski et al. 1981). Kudritski et al. conclude that T(pr) = 40000 ± 2500°K and log g = 5.3 ± 0.2 and from the spectroscopic data and light curve analysis (papers II, III) derive masses and radii for the primary and secondary components of M(pr) ≃ 0.25 M⊙, M(sec) ≃ 0.04 M⊙, R(pr) ≃ 0.16R⊙, R(sec) ≃ 0.09R⊙ respectively. Thus the primary component is a normal sd0 star whilst the secondary component is a most enigmatic object, perhaps a normal composition degenerate dwarf but of too low a mass to be on the main sequence, perhaps an evolved degenerate object but then the radius is too large. The published evolutionary models for this system (Paczynski 1980; Conti et al 1981) do not adequately describe its current status.

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The Binaries-in-Clusters Program in the Age of Imaging

Symposium - International Astronomical Union ◽

10.1017/s0074180900047914 ◽

1994 ◽

Vol 161 ◽

pp. 478-480

Author(s):

E.F. Milone ◽

J.R. McVean ◽

W. Lu ◽

S. J. Schiller ◽

G. Miller

Keyword(s):

Light Curve ◽

Star Clusters ◽

Curve Analysis ◽

Eclipsing Binaries ◽

Current Status ◽

Light Curve Analysis ◽

Star Data ◽

Boot Strap ◽

Cluster Environment

The binaries-in-clusters program of the Rothney Astrophysical Observatory has targeted eclipsing binaries in galactic star clusters since 1975. The program uses a boot strap method: fundamental star data are obtained from light curve analysis and these data then elucidate the properties of the cluster environment, such as the distance, reddening, and, through isochrone fittings, information about the age and evolution of both binary components and the cluster as a whole. Here we discuss its current status and the increasingly important role of all-cluster direct and spectroscopic imaging.

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The nature of V861 Sco (=HD 152667)

International Astronomical Union Colloquium ◽

10.1017/s0252921100095166 ◽

1981 ◽

Vol 59 ◽

pp. 481-486

Author(s):

Ian D. Howarth ◽

R. Wilson

Keyword(s):

Light Curve ◽

Loss Rate ◽

Mass Loss Rate ◽

Curve Analysis ◽

Physical Parameters ◽

Evolutionary Models ◽

Light Curve Analysis ◽

Phase Dependence ◽

Large Phase ◽

Good Agreement

AbstractThe physical parameters of the components of V861 Sco are derived from light-curve analysis and published spectroscopy. Good agreement with evolutionary models is obtained. The stellar wind is investigated using IUE data; the results include no large phase dependence of the mass loss rate and insensitivity of the velocity of the wind (measured with respect to interstellar lines) to changes in the photospheric velocity, even near the base of the wind. However, small random changes in velocity near the base of the wind are amplified to larger changes further out.

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