Bloemen S, Marsh TR, Ostensen RH, Charpinet S, Fontaine G, Degroote P, Heber U, Kawaler SD, Aerts C, Green EM, Telting J, Brassard P, Gaensicke BT, Handler G, Kurtz DW, Silvotti R, Van Grootel V, Lindberg JE, Pursimo T, Wilson PA, Gilliland RL, Kjeldsen H, Christensen-Dalsgaard J, Borucki WJ, Koch D, Jenkins JM, Klaus TC (2011)
Publication Type: Journal article
Publication year: 2011
Book Volume: 410
Pages Range: 1787-1796
Journal Issue: 3
DOI: 10.1111/j.1365-2966.2010.17559.x
The Kepler Mission has acquired 33.5 d of continuous 1-min photometry of KPD 1946+4340, a short-period binary system that consists of a subdwarf B star (sdB) and a white dwarf. In the light curve, eclipses are clearly seen, with the deepest occurring when the compact white dwarf crosses the disc of the sdB (0.4 per cent) and the more shallow ones (0.1 per cent) when the sdB eclipses the white dwarf. As expected, the sdB is deformed by the gravitational field of the white dwarf, which produces an ellipsoidal modulation of the light curve. Spectacularly, a very strong Doppler beaming (also known as Doppler boosting) effect is also clearly evident at the 0.1 per cent level. This originates from the sdB's orbital velocity, which we measure to be 164.0 ± 1.9kms-1 from supporting spectroscopy. We present light-curve models that account for all these effects, as well as gravitational lensing, which decreases the apparent radius of the white dwarf by about 6 per cent, when it eclipses the sdB. We derive system parameters and uncertainties from the light curve using Markov chain Monte Carlo simulations. Adopting a theoretical white dwarf mass-radius relation, the mass of the subdwarf is found to be 0.47 ± 0.03 M
APA:
Bloemen, S., Marsh, T.R., Ostensen, R.H., Charpinet, S., Fontaine, G., Degroote, P.,... Klaus, T.C. (2011). Kepler observations of the beaming binary KPD 1946+4340. Monthly Notices of the Royal Astronomical Society, 410(3), 1787-1796. https://doi.org/10.1111/j.1365-2966.2010.17559.x
MLA:
Bloemen, S., et al. "Kepler observations of the beaming binary KPD 1946+4340." Monthly Notices of the Royal Astronomical Society 410.3 (2011): 1787-1796.
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