The solar-type eclipsing binary system LL Aquarii

Abstract

The eclipsing binary LL Aqr consists of two late-type stars in an eccentric orbit with a period of 20.17 d. We use an extensive light curve from the SuperWASP survey augmented by published radial velocities and UBV light curves to measure the physical properties of the system. The primary star has a mass of 1.167 +/- 0.009 Msun and a radius of 1.305 +/- 0.007 Rsun. The secondary star is an analogue of the Sun, with a mass and radius of 1.014 +/- 0.006 Msun and 0.990 +/- 0.008 Rsun respectively. The system shows no signs of stellar activity: the upper limit on spot-induced rotational modulation is 3 mmag, it is slowly rotating, has not been detected at X-ray wavelengths, and the calcium H and K lines exhibit no emission. Theoretical stellar models provide a good match to its properties for a sub-solar metal abundance of Z = 0.008 and an age of 2.5 Gyr. Most low-mass eclipsing binary systems are found to have radii larger than expected from theoretical predictions, blamed on tidally-enhanced magnetic fields in these short-period systems. The properties of LL Aqr support this scenario: it exhibits negligible tidal effects, shows no signs of magnetic activity, and matches theoretical models well.

Accepted for publication in A&A. 8 pages, 5 figures (3 reduced in size), 7 tables. A full-size preprint, the data, and a catalogue of well-studied detached eclipsing binary star systems can found at http://www.astro.keele.ac.uk/jkt/

References in corpus (5)

• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• Stellar Diameters and Temperatures III. Main Sequence A, F, G, & K Stars: Additional high-precision measurements and empirical relations
• Homogeneous studies of transiting extrasolar planets. II. Physical properties
• KIC 8410637: a 408-day period eclipsing binary containing a pulsating red giant
• Absolute dimensions of eclipsing binaries. XXIV. The Be star system DW Carinae, a member of the open cluster Collinder 228

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