Related papers: Revised Temperatures For Two Benchmark M-dwarfs --…

M dwarfs are key targets for high-resolution spectroscopic analyses due to a high incidence of these stars in the solar neighbourhood and their importance as exoplanetary hosts. Several methodological challenges make such analyses…

CPD-54 810 is a double-lined detached eclipsing binary containing two mid-F type dwarfs on an eccentric 26-day orbit. We perform a combined analysis of the extensive photometry obtained by the TESS space mission along with previously…

We carried out light curve solutions of two eclipsing detached binaries on eccentric orbits observed by Kepler. The orbits and fundamental parameters of KIC 11619964 and KIC 7118545 were determined with a high accuracy by modeling of their…

We present an all-sky catalog of 2970 nearby ($d \lesssim 50$ pc), bright ($J< 9$) M- or late K-type dwarf stars, 86% of which have been confirmed by spectroscopy. This catalog will be useful for searches for Earth-size and possibly…

M-dwarf stars provide very favourable conditions to find habitable worlds beyond our solar system. The estimation of the fundamental parameters of the transiting exoplanets rely on the accuracy of the theoretical predictions for radius and…

M dwarf systems offer an opportunity to study terrestrial exoplanetary atmospheres due to their small size and cool temperatures. However, the extreme conditions imposed by these host stars raise question about whether their close-in rocky…

In this paper, we derive the fundamental properties of 1SWASPJ011351.29+314909.7 (J0113+31), a metal-poor (-0.40 +/- 0.04 dex), eclipsing binary in an eccentric orbit (~0.3) with an orbital period of ~14.277 d. Eclipsing M dwarfs orbiting…

We describe a method for accurately determining M dwarf metallicities with spectral synthesis based on abundance analyses of visual binary stars. We obtained high resolution, high signal-to-noise spectra of each component of five visual…

We announce the discovery of a new eclipsing hot subdwarf B + M dwarf binary, EC 10246-2707, and present multi-colour photometric and spectroscopic observations of this system. Similar to other HW Vir-type binaries, the light curve shows…

In this study, the distributions of the double-lined detached binaries (DBs) on the planes of mass-luminosity, mass radius and mass-effective temperature have been studied. We improved the classical mass-luminosity relation based on the…

Model atmospheres have been computed for M dwarfs that are strongly irradiated by nearby hot companions. A variety of primary and secondary spectral types are explored in addition to models specific to four known systems: GD 245, NN Ser, AA…

The ability to perform detailed chemical analysis of Sun-like F-, G-, and K-type stars is a powerful tool with many applications including studying the chemical evolution of the Galaxy and constraining planet formation theories.…

We have obtained 1.0-2.5um spectra at R~600 of 14 disk dwarfs with spectral types M6 to L7. For four of the dwarfs we have also obtained infrared spectra at R~3000 in narrow intervals. In addition, we present new L' photometry for four of…

There are no field brown dwarf analogs with measured masses, radii, and luminosities, precluding our ability to connect the population of transiting brown dwarfs with measurable masses and radii and field brown dwarfs with measurable…

M subdwarfs are metal poor and cool stars. They are important probes of the old galactic populations. However, they remain elusive due to their low luminosity. Observational and modeling efforts are required to fully understand the physics…

We have obtained infrared (1 to 2.5 micron) spectroscopy for 42 halo and disk dwarfs with spectral type M1 to M6.5. These data are compared to synthetic spectra generated by the latest model atmospheres of Allard & Hauschildt. Photospheric…

Benchmark brown dwarfs in wide binary systems are crucial for characterizing substellar objects and calibrating atmospheric and evolutionary models. However, brown dwarf benchmarks with subsolar metallicity, very cool temperatures, or…

We report the discovery of an eclipsing binary -- PTF1 J072456$+$125301-- composed of a subdwarf B (sdB) star ($g'=17.2^m$) with a faint companion. Subdwarf B stars are core helium-burning stars, which can be found on the extreme horizontal…

The asteroseismic and planetary studies, like all research related to stars, need precise and accurate stellar atmospheric parameters as input. We aim at deriving the effective temperature (Teff), the surface gravity (log g), the…

We present Hubble Space Telescope UV spectra of the 4.6 h period double white dwarf SDSS J125733.63+542850.5. Combined with Sloan Digital Sky Survey optical data, these reveal that the massive white dwarf (secondary) has an effective…