* Astronomy

Title: The quest for companions to post-common envelope binaries. II. NSVS14256825 and HS0705+6700
Authors: K. Beuermann (1), P. Breitenstein (2), B. Ddebski (3), J. Diese (4), P. A. Dubovsky (5), S. Dreizler (1), F. V. Hessman (1), K. Hornoch (6), T.-O. Husser (1), G. Pojmanski (7), M. Wolf (8), P. R. Wozniak (9), P. Zasche (8), B. Denk (2), M. Langer (2), C. Wagner (2), D. Wahrenberg (2), T. Bollmann (4), F. N. Habermann (4), N. Haustovich (4), M. Lauser (4), F. Liebing (4), F. Niederstadt ((1) Institut fuer Astrophysik, Georg-August-Universitaet, Goettingen/DE, (2) Westfalen-Kolleg, Dortmund/DE, (3) Astronomical Observatory, Jagiellonian University, Krakow/PL, (4) Max-Planck-Gymnasium, Goettingen/DE, (5) Vihorlat Observatory, Humenne/SK, (6) Academy of Sciences, Ondrejov/CZ, (7) Warsaw University Astronomical Observatory, Warszawa/PL, (8) Astronomical Institute, Charles University, Praha/CZ, (9) Los Alamos National Laboratory, NM/USA)

We report new mid-eclipse times of the two close binaries NSVS14256825 and HS0705+6700, harbouring an sdB primary and a low-mass main-sequence secondary. Both objects display clear variations in the measured orbital period, which can be explained by the action of a third object orbiting the binary. If this interpretation is correct, the third object in NSVS14256825 is a giant planet with a mass of roughly 12 Jupiter masses. For HS0705+6700, we provide evidence that strengthens the case for the suggested periodic nature of the eclipse time variation and reduces the uncertainties in the parameters of the brown dwarf implied by that model. The derived period is 8.4 yr and the mass is 31 Jupiter masses, if the orbit is coplanar with the binary. This research is part of the PlanetFinders project, an ongoing collaboration between professional astronomers and student groups at high schools.

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