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arXiv · 0707.4540

The first high-amplitude delta Scuti star in an eclipsing binary system

J. L. Christiansen·A. Derekas·M. C. B. Ashley·J. K. Webb·M. G. Hidas·D. W. Hamacher·L. L. Kiss
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Abstract

We report the discovery of the first high-amplitude delta Scuti star in an eclipsing binary, which we have designated UNSW-V-500. The system is an Algol-type semi-detached eclipsing binary of maximum brightness V = 12.52 mag. A best-fitting solution to the binary light curve and two radial velocity curves is derived using the Wilson-Devinney code. We identify a late A spectral type primary component of mass 1.49+/-0.02 M_sun and a late K spectral type secondary of mass 0.33+/-0.02 M_sun, with an inclination of 86.5+/-1.0 degrees, and a period of 5.3504751+/-0.0000006 d. A Fourier analysis of the residuals from this solution is performed using PERIOD04 to investigate the delta Scuti pulsations. We detect a single pulsation frequency of f_1 = 13.621+/-0.015 c/d, and it appears this is the first overtone radial mode frequency. This system provides the first opportunity to measure the dynamical mass for a star of this variable type; previously, masses have been derived from stellar evolution and pulsation models.

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J. L. Christiansen, A. Derekas, M. C. B. Ashley, J. K. Webb, M. G. Hidas, D. W. Hamacher, L. L. Kiss. 2007-07-31. The first high-amplitude delta Scuti star in an eclipsing binary system. https://doi.org/10.1111/j.1365-2966.2007.12338.x

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