Related papers: The young, active binary star EK Draconis
We report the discovery via radial velocity of a short-period (P = 2.430420 \pm 0.000006 days) companion to the F-type main sequence star TYC 2930-00872-1. A long-term trend in the radial velocities indicates the presence of a tertiary…
We present results from an adaptive optics survey for substellar and stellar companions to Sun-like stars. The survey targeted 266 F5-K5 stars in the 3Myr to 3Gyr age range with distances of 10-190pc. Results from the survey include the…
In this Letter, the radial velocity variability of the chemically peculiar star Epsilon Ursae Majoris ($\epsilon$ UMa) from the sharp cores of the hydrogen lines is investigated. This study is based on the ELODIE archival data obtained at…
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…
The companion to the G0V star HR7672 directly imaged by Liu et al. (2002) has moved measurably along its orbit since the discovery epoch, making it possible to determine its dynamical properties. Originally targeted with adaptive optics…
The interplay between radiative diffusion, rotation, convection, and magnetism in metallic-line chemically peculiar stars is still not fully understood. Recently, evidence has emerged that these effects can work together. Our goal is to…
We observed stars with variable radial velocities to determine their spectroscopic orbits. Velocities of 132 targets taken over a time span reaching 30 years are presented. They were measured with the correlation radial velocity…
OO Dra is a short-period Algol system with a $\delta$ Sct-like pulsator. We obtained time-series spectra between 2016 February and May to derive the fundamental parameters of the binary star and to study its evolutionary scenario. The…
We identified a new post-interaction binary, HIP 15429, consisting of a stripped star and a recently formed, rapidly rotating Be star companion ($v \sin i \approx 270$ km/s) sharing many similarities with recently identified bloated…
We present a dynamical study of the intermediate polar cataclysmic variable YY Dra based on time-series observations in the $K$ band, where the donor star is known to be the major flux contributor. We covered the $3.97$-h orbital cycle with…
We present a spectroscopic/photometric analysis of the rapid rotator KIC8429280, discovered by ourselves as a very young star and observed by the Kepler mission. We use spectroscopic/photometric ground-based data to derive stellar…
We aim to understand the interplay between non-radial oscillations and stellar magnetic activity and test the feasibility of doing asteroseismology of magnetically active stars. We analyze 30 years of photometric time-series data, 3 years…
We present high resolution Hubble Space Telescope ultraviolet spectroscopy of the dwarf nova EK TrA obtained in deep quiescence. The Space Telescope Imaging Spectrograph data reveal the broad Ly-alpha absorption profile typical of a…
We report the detection of a long-period companion to the nearby solar-type star HD\,38973 using precision radial-velocity measurements. The radial-velocity data reveal a coherent Keplerian signal with a period of $\sim$3000~days and…
HR 8799 is a young A5/F0 star hosting four directly imaged giant planets at wide separations ($\sim$16-78 au) which are undergoing orbital motion and have been continuously monitored with adaptive optics imaging since their discovery over a…
We report the discovery of a radial velocity signal that can be interpreted as a planetary-mass candidate orbiting the K dwarf HD26965, with an orbital period of 42.364$\pm$0.015 days, or alternatively, as the presence of residual,…
The two stars that form the subject of this paper are both short-period double- lined eclipsing binaries having non-circular orbits despite their short periods. Although the HD type of HD 152028 is G0, the integrated spectral type of the…
We perform a search for faint, common proper motion companions of Hipparcos stars using the recently published LSPM-north catalog of stars with proper motion mu>0.15 arcsec/yr. Our survey uncovers a total of 521 systems with angular…
In 2016, Kepler/K2 detected a system of two sub-Neptunes transiting the star HD 224018, one of them showing a mono-transit event. In 2017, we began a spectroscopic follow-up with HARPS-N to measure the dynamical masses of the planets using…
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…