Related papers: The first Doppler imaging of the active binary pro…

The LAMOST spectra and $\it{Kepler}$ light curves are combined to investigate the detached eclipsing binary KIC 8098300, which shows the O'Connell effect caused by spot/facula modulation. The radial velocity (RV) measurements are derived by…

With orbital periods of the order of tens of minutes or less, the AM Canum Venaticorum stars are ultracompact, hydrogen deficient binaries with the shortest periods of any binary subclass, and are expected to be among the strongest…

Context. This work is part of a long-term spectroscopic study of a sample of 30 multiple stars with early-type components. In this second paper we present the results of six multiple systems in which new stellar components have been…

Double-lined spectroscopic orbital elements have recently been found for the central binary in the massive triple, delta Orionis A based on radial velocities from cross-correlation techniques applied to IUE high dispersion spectra and He I…

Context. The statistical properties of binary stars are clues for understanding their formation process. A radial velocity survey was carried on amongst nearby G-type stars and the results were published in 1991. Aims. The survey of radial…

We present temperature maps of RS CVn star lambda Andromedae, reconstructed from interferometric data acquired in 2010 and 2011 by the MIRC instrument at the Center for High Angular Resolution Astronomy Array. To constrain the stellar…

We compare stellar photometric variability, as measured from Kepler light curves by Basri et al. (2011), with measurements of radial velocity (RV) root-mean-square (RMS) variations of all California Planet Search overlap stars. We newly…

We study the Be star $\delta$ Cen circumstellar disk using long-baseline interferometry which is the only observing technique capable of resolving spatially and spectroscopically objects smaller than 5 mas in the H and K b and. We used the…

Brightness variations due to dark spots on the stellar surface encode information about stellar surface rotation and magnetic activity. In this work, we analyze the Kepler long-cadence data of 26,521 main-sequence stars of spectral types M…

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,…

We used high-quality Kepler photometry and spectroscopic data to investigate the Kepler binary candidate KIC 5988140. Using the spectrum synthesis method, we derived the fundamental parameters Teff, log g, [M/H], and v.sini and the…

We derive single-epoch radial velocities for a sample of 56 B-type stars members of the subgroups Upper Scorpius, Upper Centaurus Lupus and Lower Centaurus Crux of the nearby Sco-Cen OB association. The radial velocity measurements were…

Circumbinary planets - planets that orbit both stars in a binary system - offer the opportunity to study planet formation and orbital migration in a different environment compare to single stars. However, despite the fact that > 90% of…

We present the results of differential, time series photometry for GSC 02038-00293, a suspected RS CVn binary, using data collected with the Open University's PIRATE robotic telescope located at the Observatori Astronomic de Mallorca…

We have used deep V-band and JHKs-band observations to investigate variability and stellar populations near the Galactic plane in Centaurus, and compared the observations with the Galactic model of Besancon. By applying image subtraction…

We carried out spectroscopic observations with Subaru/HDS of 50 solar-type superflare stars found from Kepler data. More than half (34 stars) of the target stars show no evidence of the binary system, and we confirmed atmospheric parameters…

We present the first analysis of W Vir stars observed by the Kepler space telescope in the K2 mission. Clear cycle-to-cycle variation were detected in the light curves of KT Sco and the globular cluster member M80-V1. While the variations…

We have used high-speed spectroscopy of the rapidly oscillating Ap (roAp) star HD99563 to study the pulsation amplitude and phase behaviour of elements in its stratified atmosphere over one 2.91-d rotation cycle. We identify spectral…

We present updated magnetic field maps of the chemically peculiar B9p star $\alpha^2$ CVn created using a series of time resolved observations obtained using the high resolution spectropolarimeters ESPaDOnS and Narval. We compare these new…

We use Doppler imaging techniques to determine the dependence of starspot rotation rates on latitude in an homogeneous sample of young, rapidly-rotating solar analogues. A solar-like differential rotation law is used, where the rotation…