Related papers: The Highly Eccentric Pre-Main Sequence Spectroscop…

PSR J1903+0327 is a mili-second pulsar with a mass of 1.67 M_{\odot} in a highly eccentric orbit (e=0.44) around a main-sequence star. This unique system cannot be reconciled with current observations where milli-second pulsars are…

We present the discovery of \thisstar\ (HD 58730), a very low mass ratio ($q \equiv M_2/M_1 \approx 0.07$) eclipsing binary (EB) identified by the Kilodegree Extremely Little Telescope (KELT) survey. We present the discovery light curve and…

PSR J1306--40 is a millisecond pulsar binary with a non-degenerate companion in an unusually long $\sim$1.097 day orbit. We present new optical photometry and spectroscopy of this system, and model these data to constrain fundamental…

We report the discovery of a new BY Dra-type binary identified as the optical counterpart of the bright source RX J0222.4+4729 detected during the ROSAT All-Sky Survey (Voges et al. 1996). The star is a $V \sim 11.1$, near-by ($\sim 30$…

RX J0806.3+1527 is suspected to be a double-degenerate white dwarf binary. We present first results of our NLTE analysis of its optical spectrum. The VLT/FORS1 data show a composite spectrum consisting of a blue continuum and superimposed…

V1022 Cas has been known as a spectroscopic binary for a century. It was found to be eclipsing based on photometry from the Hipparcos satellite, and an astrometric orbit was recently obtained from near-infrared interferometry. We present…

FUSE spectra were obtained of the supersoft X-ray binary RX J0019.8+2156 (QR And) during 16 consecutive spacecraft orbits, covering the binary orbit (P=15.85 hr) with about 0.2 phase overlap. The spectrum is dominated by strong H2…

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…

The MOST photometric space mission discovered an eclipsing binary among its guide stars in June 2006 which combines a relatively large eccentricity e = 0.20 with an orbital period of only 2.27 days. HD 313926 appears to consist of two…

We have investigated multiband optical photometric variability and stability of the H$\alpha$ line profile of the transient X-ray binary IGR J01583+6713. We set an upper limit of 0.05 mag on photometric variations in the {\it V} band over a…

Ongoing ground-based radial-velocity observations seeking to detect circumbinary planets focus on single-lined binaries even though over nine in every ten binary systems in the solar-neighbourhood are double-lined. Double-lined binaries are…

The globular cluster ultraluminous X-ray source, RZ2109, is a complex and unique system which has been detected at X-ray, ultra-violet, and optical wavelengths. Based on almost 20 years of Chandra and XMM-Newton observations, the X-ray…

We have analyzed nearly eight years of MACHO optical photometry of the supersoft X-ray binary RX J0513.9-6951 and derived a revised orbital period and ephemeris. Previously published velocities are reinterpreted using the new ephemeris. We…

We present IRTF SpeX observations of the M/L binary system 2MASS J17072343-0558249. SpeX imaging resolves the system into a 1"01+/-0.17 visual binary in which both components have red near infrared colors. Resolved low-resolution (R~150)…

We report optical photometric and SOAR spectroscopic observations of an X-ray source found within the localization error of the Fermi-LAT unidentified gamma-ray source J0523.5-2529. The optical data show periodic flux modulation and radial…

We report the very first analysis of 27 eclipsing binary systems with high eccentricities that sometimes reach up to 0.8. The orbital periods for these systems range from 1.4 to 37 days, and the median of the sample is 10.3 days. Star…

We report the detection of eclipses in GJ 3236, a bright (I = 11.6) very low mass binary system with an orbital period of 0.77 days. Analysis of light- and radial velocity curves of the system yielded component masses of 0.38 +/- 0.02 and…

In this paper we present a spectroscopic study of six double-lined binaries, five of which were recently discovered in a high-resolution spectroscopic survey of optical counterparts of stellar X-ray sources. Thanks to high-resolution…

The gamma-ray binary LS I+61 303 has been widely monitored at different wavelengths since its discovery more than sixty years ago. However, the nature of the compact object and the peculiar behavior of the system are still largely debated.…

This paper is framed within a large project devoted to studying the presence of circumstellar material around main sequence stars, and looking for exocometary events. The work concentrates on HR 10 (A2 IV/V), known for its conspicuous…