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Hierarchical triple systems comprise a close binary and a more distant component. They are important for testing theories of star formation and of stellar evolution in the presence of nearby companions. We obtained 218 days of Kepler photometry of HD 181068 (magnitude of 7.1), supplemented by groundbased spectroscopy and interferometry, which show it to be a hierarchical triple with two types of mutual eclipses. The primary is a red giant that is in a 45-day orbit with a pair of red dwarfs in a close 0.9-day orbit. The red giant shows evidence for tidally-induced oscillations that are driven by the orbital motion of the close pair. HD 181068 is an ideal target for studies of dynamical evolution and testing tidal friction theories in hierarchical triple systems., Comment: 22 pages, including supporting on-line material. This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science Vol. 332 no. 6026 pp. 216-218 (8 April 2011), doi:10.1126/science.1201762. http://www.sciencemag.org/content/332/6026/216.full

We present the results of space-based photometric and ground-based spectroscopic observing campaigns on the gamma-ray binary LS 5039. The new orbital and physical parameters of the system are similar to former results, except we found a lower eccentricity. Our MOST-data show that any broad-band optical photometric variability at the orbital period is below the 2 mmag level. Light curve simulations support the lower value of eccentricity and imply that the mass of the compact object is higher than 1.8 solar masses., Comment: 2 pages, 1 figure (with 2 panels); to be published in the Proceedings: From Interacting Binaries to Exoplanets: Essential Modeling Tools, IAU Symposium 282 (18-22 July, 2011, Tatranska Lomnica, Slovakia)

LS 5039 is a relatively close microquasar consisting of a late O-type star and a compact object (very possibly a black hole) on a highly eccentric orbit with a period of 3.9 days. The high X-ray, gamma-ray and radio luminosity indicate light-matter interaction, which arise from the stellar wind of the primary star accreting toward the black hole. Former examinations suggest that LS 5039 could be a prototype of wind-fed high mass X-ray binaries (WXBs) with diskless main sequence O primaries. Now there is a great chance to better understand the configuration and the physical processes in the exotic system. In July 2009 LS 5039 was followed by the Canadian MOST space telescope to get ultraprecise photometric data in a month-long semi-continuous time series. Parallel to this, we have taken simultaneous high-resolution optical spectra using the 2.3m ANU telescope of the Siding Spring Observatory, supplemented with further data obtained in early August 2009 with the same instrument. Here we present the first results from the new echelle spectra, which represent the best optical spectroscopy ever obtained for this intriguing system. We determined fundamental orbital and physical parameters of LS 5039 and examined the configuration and the circumstellar environment of the system via radial velocity measurements and detailed line-profile analysis of H-Balmer, He I and He II lines., Comment: 6 pages, 2 figures (with 8 panels); Proceedings of the 5th Workshop of Young Researchers in Astronomy and Astrophysics, Budapest, 2009; to be published in J. Phys.: Conf. Series (JPCS)