Related papers: The Visual Orbit and Evolutionary State of 12 Boot…

We present a spectroscopic characterisation and a new orbital solution for the binary system beta Cyg Aa/Ac (MCA 55), the primary component (beta Cyg A) of the well-known wide double star Albireo. By matching evolutionary tracks to the…

Rotationally-modulated variability of brown dwarfs and giant planets provides unique information about their surface brightness inhomogeneities, atmospheric circulation, cloud evolution, vertical atmospheric structure, and rotational…

We describe the results of the world-wide observing campaign of the highly eccentric Be binary system delta Scorpii 2011 periastron passage which involved professional and amateur astronomers. Our spectroscopic observations provided a…

We present the visual orbit of the double-lined spectroscopic binary HD 224355 from interferometric observations with the CHARA Array, as well as an updated spectroscopic analysis using echelle spectra from the Apache Point Observatory 3.5m…

In anticipation of the possible collision between a circumstellar disk and the secondary star in the highly eccentric binary system Delta Scorpii, high angular resolution interferometric observations have been acquired aimed at revising the…

Classical Wolf-Rayet stars are descendants of massive OB-type stars that have lost their hydrogen-rich envelopes, and are in the final stages of stellar evolution, possibly exploding as type Ib/c supernovae. It is understood that the…

We report on the results of a six-month photometric study of the main-belt binary C-type asteroid 121 Hermione, performed during its 2007 opposition. We took advantage of the rare observational opportunity afforded by one of the annual…

Hot subdwarf (sdB) stars in binary systems with main-sequence (MS) companions provide valuable insights into mass transfer and envelope ejection processes in binary evolution. Their mass ratios, orbital periods, and stellar properties…

To determine the parameters (masses, orbital period) of a binary, one requires among others the inclination, which is best determined from a visual orbit. The next generation of interferometers can provide visual orbits for a large number…

Double-lined spectroscopic binaries (SB2s) are one of the main sources of stellar masses, as additional observations are only needed to give the inclinations of the orbital planes in order to obtain the individual masses of the components.…

Castor is a system of six stars in which the two brighter objects, Castor A and B, revolve around each other every $\sim$450 yr and are both short-period spectroscopic binaries. They are attended by the more distant Castor C, which is also…

We report follow-up studies of 35 recently-discovered cataclysmic variables (CVs), 32 of which were found in large, automated synoptic sky surveys. The objects were selected for observational tractability. For 34 of the objects we present…

We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive…

We present a comprehensive set of physical and geometrical parameters for each of the components of the close visual binary system Hip 11253 (HD14874). We present an analysis for the binary and multiple stellar systems with the aim to…

Protostellar binaries harbour complex environment morphologies. Observations represent a snapshot in time, and projection and optical depth effects impair our ability to interpret them. Careful comparison with high-resolution models that…

Hubble Space Telescope observations of Uranus- and Neptune-crossing object (65489) Ceto/Phorcys (provisionally designated 2003 FX128) reveal it to be a close binary system. The mutual orbit has a period of 9.554 +/- 0.011 days and a…

We present near-infrared parallax and proper motion astrometry for 74 L-dwarfs and 99 T-dwarfs, as single objects or in binary systems, obtained with the ASTROCAM astrometric imager on the USNO, Flagstaff Station 1.55-m telescope over two…

We analyse archival optical data on the binary companion to the millisecond pulsar \j1045\ obtained with the Very Large Telescope. A possible optical counterpart candidate %source position coincides with the pulsar coordinates is found at…

The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…

We present high resolution echelle spectra taken during four observing runs from 1999 to 2001 of the recently X-ray/EUV selected chromospherically active binary BK Psc (2RE J0039+103). Our observations confirm the single-lined spectroscopic…