A New Lower Main Sequence Eclipsing Binary with Detached Components

• Autorzy: Rozyczka M. , Kaluzny J. , Pietrukowicz P. , Pych W. , Mazur B. , Catelan M. , Thompson I. B.
• Języki publikacji: EN

Abstrakty

EN

We present an analysis of NGC2204-S892 - a new detached eclipsing binary composed of two late K dwarfs. Based on three photometric campaigns launched in 2008 we obtained five light curves (three in V, one in B and one in I), and derived an orbital period. We also obtained 20 VLT/UVES spectra, enabling accurate radial velocity measurements. The derived masses and radii of the components are consistent with the empirical mass-radius relationship established recently for lower main sequence stars in binary systems; in particular we find that both stars are oversized compared to theoretical models. NGC2204-S892 is very active: both components show variable emission in Hα and Hβ and are heavily spotted, causing the light curve to show appreciable changes on a timescale of weeks. Our results add to the increasing evidence that the observed inflation of the radii of K and M stars is related to high levels of magnetic activity.

Słowa kluczowe

EN

binaries: eclipsing; Stars: individual: NGC2204-S892; Stars: low-mass; brown dwarfs

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2009
• Tom: Vol. 59, No. 4
• Strony: 385--401
• Opis fizyczny: Bibliogr. 30 poz., tab., wykr.

Twórcy

autor

Rozyczka M.

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

autor

Kaluzny J.

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

autor

Pietrukowicz P.

• Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland
• Departamento de Astronomia y Astrofisica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile

autor

Pych W.

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

autor

Mazur B.

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

autor

Catelan M.

• Departamento de Astronomia y Astrofisica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile

autor

Thompson I. B.

• The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA91101, USA

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