Related papers: Orbital parameters, chemical composition, and magn…
Differences in the elemental abundances of planet hosting stars in binary systems can give important clues and constraints about planet formation and evolution. In this study we performed a high-precision, differential elemental abundance…
HD 100453AB is a 10+/-2 Myr old binary whose protoplanetary disk was recently revealed to host a global two-armed spiral structure. Given the relatively small projected separation of the binary (1.05", or ~108 au), gravitational…
HD 149277 is a rare SB2 system with a slowly rotating magnetic He-rich primary with $P_{\rm rot}=25.4$ d. The CFHT/ESPaDOnS archive spectra revealed $P_{\rm orb}=11.5192 \pm 0.0005$ d indicating strong subsynchronous rotation of the primary…
We report about HD 213258, an Ap star that we recently identified as presenting a unique combination of rare, remarkable properties. Our study of this star is based on ESPaDOnS Stokes I and V data obtained at 7 epochs spanning a time…
Aims. HD166734 is an eccentric eclipsing binary system composed of two supergiant O-type stars, orbiting with a 34.5-day period. In this rare configuration for such stars, the two objects mainly evolve independently, following single-star…
Binary systems containing a magnetic white dwarf and a main-sequence star are considered extremely rare, perhaps non-existent. In the course of a search of magnetic fields in high-mass white dwarfs we have discovered a Sirius-like wide…
We analyze archival data from Bailey and co-workers from the $Magellan$ adaptive optics system and present the first 0.9 $\mu$m detection ($z' = 20.3\pm0.4$ mag; $\Delta z'=13.0\pm0.4$ mag) of the 11 $M_\mathrm{Jup}$ circumbinary planet HD…
Analyses of multi-epoch, high-resolution (~ 50000) optical spectra of seven early-type systems provided various important new insights with respect to their multiplicity. First determinations of orbital periods were made for HD 92206C…
Binaries in double-lined spectroscopic systems provide a homogeneous set of stars. Differences of parameters, such as age or initial conditions, which otherwise would have strong impact on the stellar evolution, can be neglected. The…
The frequent presence of weak magnetic fields on the surface of spotted late-B stars with HgMn peculiarity in binary systems has been controversial during the two last decades. We re-analyse available spectropolarimetric material by…
PG1544+488 is an exceptional short-period spectroscopic binary containing two subdwarf B stars. It is also exceptional because the surfaces of both components are extremely helium-rich. We present a new analysis of spectroscopy of…
Chemically peculiar A stars (Ap) are extreme examples of the interaction of atomic element diffusion processes with magnetic fields in stellar atmospheres. The rapidly oscillating Ap stars provide a means for studying these processes in 3D…
HD 156324 is an SB3 (B2V/B5V/B5V) system in the Sco OB4 association. The He-strong primary possesses both a strong magnetic field, and H$\alpha$ emission believed to originate in its Centrifugal Magnetosphere (CM). We analyse a large…
We present the first full orbital and physical analysis of HD 187669, recognized by the All-Sky Automated Survey (ASAS) as the eclipsing binary ASAS J195222-3233.7. We combined multi-band photometry from the ASAS and SuperWASP public…
We performed a highly sensitive search for magnetic fields on a large set of HgMn stars. With the aid of a new polarimeter attached to the HARPS spectrometer at the ESO 3.6m-telescope, we obtained high-quality circular polarization spectra…
We employ high resolution spectroscopy and spectropolarimetry to derive the physical properties and magnetic characteristics of the multiple system HD 164492C, located in the young open cluster M20. The spectrum reveals evidence of 3…
We report on Keck Interferometer observations of the double-lined binary (B) component of the quadruple pre-main sequence (PMS) system HD 98800. With these interferometric observations combined with astrometric measurements made by the…
The double-lined spectroscopic binary HD 104237 (DX Cha) is part of a complex system of some half-dozen nearby young stars. We report a significant change from an orbit for the SB2 system derived from 1999-2000 observations. We obtain…
The late B-type star V772 Cas (HD 10260) was previously suspected to be a rare example of a magnetic chemically peculiar star in an eclipsing binary system. Photometric observations of this star obtained by the TESS satellite show clear…
High resolution spectropolarimetric observations of the strongly magnetic, super-slowly rotating rapidly oscillating Ap star HD166473 are used to investigate the implications of the presence of a variable strong magnetic field on the…