An Unusual Eclipsing Blue Straggler V8-NGC 6752

• Autorzy: Kaluzny J. , Rozyczka M. , Thompson I. B. , Zloczewski K.
• Języki publikacji: EN

Abstrakty

EN

We report the analysis of a binary blue straggler in NGC 6752 with a short orbital period of 0.315 d and a W UMA-type light curve. We use photometric data spanning 13 years to place limits on the mass ratio (0.15≤q≤0.35), luminosity ratio (L₁/L₂≈4.0) and the ratio of the radii of the components (r₁/r2₂≈2.0). The effective temperatures of the components are nearly identical, and the system is detached or semi-detached (in the latter case the component filling its Roche lobe is the secondary). Such a configuration is unusual given the shortness of the orbital period, and it must have resulted from substantial mass exchange. We suggest that some secondaries of W UMa-type stars, normally regarded as main sequence objects which fill their Roche lobes to different degrees, in fact may be shell-burning cores of originally more massive components.

Słowa kluczowe

EN

blue stragglers; binaries: eclipsing; globular clusters: individual: NGC 6752

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2009
• Tom: Vol. 59, No. 4
• Strony: 371--383
• Opis fizyczny: Bibliogr. 39 poz., rys., tab., wykr.

Twórcy

autor

Kaluzny J.

• Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Rozyczka M.

• Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Thompson I. B.

• Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101, USA

autor

Zloczewski K.

• Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland

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