346 datasets found

In this study we continue spectral class determinations for large number of optically faint periodic variables taken from the Catalina Surveys Data Release 1 (CSDR1)and LINEAR...

The results of a spectral classification of 257 M stars observed in the Cepheus region are given. Their equatorial coordinates, photographic stellar magnitudes, and spectral...

Observations of low-mass stars have frequently shown a disagreement between observed stellar radii and radii predicted by theoretical stellar structure models. This "`radius...

Detailed chemical composition of stars is of prime interest for a range of topics in modern stellar astrophysics, such as the chemical evolution of the Galaxy or the formation,...

A blue depression is found in the spectra of M dwarfs from 4000 to 4500{AA}. This depression shows an increase toward lower temperatures though is particularly sensitive to...

Eclipsing binaries are important benchmark objects to test and calibrate stellar structure and evolution models. This is especially true for binaries with a fully convective...

The accuracy of theoretical mass, radius and effective temperature values for M-dwarf stars is an active topic of debate. Differences between observed and theoretical values...

We present here medium resolution ({lambda}/{Delta}{lambda}~1200) H- and K-band spectra of M-type dwarf stars covering the wavelength ranges 1.50-1.80{mu}m and 1.95-2.45{mu}m....

We present rotation period measurements for 107 M dwarfs in the mass range 0.15-0.70M_{sun} observed within the context of the APACHE photometric survey. We measure rotation...

In this paper we present a catalogue of 11745 brown dwarfs with spectral types ranging from L0 to T9, photometrically classified using data from the Dark Energy Survey (DES)...

Detailed studies of the Sun have shown that sunspots and solar flares are closely correlated. Photometric data from Kepler/K2 has allowed similar studies to be carried out on...

We determine the physical parameters of the outer atmosphere of a sample of eight evolved stars, including the red supergiant {alpha} Scorpii, the red giant branch stars {alpha}...

We investigated almost 500 stars distributed among 193 binary or multiple systems made of late-F, G-, or early-K primaries and late-K or M dwarf companion candidates. For all of...

Present and future high-precision radial-velocity spectrometers dedicated to the discovery of low-mass planets orbiting low-mass dwarfs need to focus on the best selected stars...

We study the relation between stellar rotation and magnetic activity for a sample of 134 bright, nearby M dwarfs observed in the Kepler Two-Wheel (K2) mission during campaigns...

We develop a method to identify the spectroscopic signature of unresolved L-dwarf ultracool companions, which compares the spectra of candidates and their associated control...

We present the results of a survey of the low-mass star and brown dwarf population of the 25 Orionis group. Using optical photometry from the CIDA (Centro de Investigaciones de...

We present an all-sky catalogue of 2970 nearby (d<~50pc), bright (J<9) M- or late K-type dwarf stars, 86% of which have been confirmed by spectroscopy. This catalogue will...

Using the Position and Proper Motion Extended-L (PPMXL) catalogue, we have used optical and near-infrared colour cuts together with a reduced proper motion cut to find bright M...

We have analysed 10 months of public data from the Kepler space mission to measure rotation periods of main-sequence stars with masses between 0.3 and 0.55M_{sun}. To derive the...