Vos J, Ostensen RH, Degroote P, De Smedt K, Green EM, Heber U, Van Winckel H, Acke B, Bloemen S, De Cat P, Exter K, Lampens P, Lombaert R, Masseron T, Menu J, Neyskens P, Raskin G, Ringat E, Rauch T, Smolders K, Tkachenko A (2012)
Publication Type: Journal article
Publication year: 2012
Book Volume: 548
Article Number: A6
DOI: 10.1051/0004-6361/201219723
Context. The predicted orbital period histogram of a subdwarf B (sdB) population is bimodal with a peak at short (<10 days) and long (>250 days) periods. Observationally, however, there are many short-period sdB systems known, but only very few long-period sdB binaries are identified. As these predictions are based on poorly understood binary interaction processes, it is of prime importance to confront the predictions to well constrained observational data. We therefore initiated a monitoring program to find and characterize long-period sdB stars. Aims. In this contribution we aim to determine the absolute dimensions of the long-period binary system PG 1104+243 consisting of an sdB and a main-sequence (MS) component, and determine its evolution history. Methods. High-resolution spectroscopy time-series were obtained with HERMES at the Mercator telescope at La Palma, and analyzed to determine the radial velocities of both the sdB and MS components. Photometry from the literature was used to construct the spectral energy distribution (SED) of the binary. Atmosphere models were used to fit this SED and determine the surface gravity and temperature of both components. The gravitational redshift provided an independent confirmation of the surface gravity of the sdB component. Results. An orbital period of 753 ± 3 d and a mass ratio of q = 0.637 ± 0.015 were found for PG 1104+243 from the radial velocity curves. The sdB component has an effective temperature of T
APA:
Vos, J., Ostensen, R.H., Degroote, P., De Smedt, K., Green, E.M., Heber, U.,... Tkachenko, A. (2012). The orbits of subdwarf B + main-sequence binaries: I. the sdB+G0 system PG 1104+243. Astronomy & Astrophysics, 548. https://doi.org/10.1051/0004-6361/201219723
MLA:
Vos, Joris, et al. "The orbits of subdwarf B + main-sequence binaries: I. the sdB+G0 system PG 1104+243." Astronomy & Astrophysics 548 (2012).
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