Related papers: Spectroscopic Data Analysis for Precise Determinat…
We present measurements of fundamental astrophysical properties of nearby, low-mass, K- and M-dwarfs from our DISCOS survey (DIameterS of COol Stars). The principal goal of our study is the determination of linear radii and effective…
Starspots are ubiquitous in young, low-mass stars, yet their impact on the spectral classification and fundamental parameter inference of pre-main sequence stars (PMS) has been largely overlooked. In this study, we demonstrate that cool…
Modern precise radial velocity spectrometers are designed to infer the existence of planets orbiting other stars by measuring few-nm shifts in the positions of stellar spectral lines recorded at high spectral resolution on a large-area…
Radiation from accretion discs in cataclysmic variable stars (CVs) provides fundamental information about the properties of these close binary systems and about the physics of accretion in general. The detailed diagnostics of accretion disc…
Observations of thermal radiation from neutron stars allow one to measure the surface temperatures and confront them with cooling scenarios. Detection of gravitationally redshifted spectral lines can yield the mass-to-radius ratio. In the…
We have been using Keck laser guide star adaptive optics to monitor the orbits of ultracool binaries, providing dynamical masses at lower luminosities and temperatures than previously available and enabling strong tests of theoretical…
Many active stars are covered in spots, much more so than the Sun, as indicated by spectroscopic and photometric observations. It has been predicted that star spots induce non-zero intrinsic linear polarization by breaking the visible…
New determinations of effective temperatures of 23 magnetic, chemically peculiar (mCP) stars were obtained from a fit of metal enhanced model atmospheres to the observed spectral energy distributions (SED) from UV to red. The…
We report homogeneous spectroscopic determinations of the effective temperature, metallicity, and projected rotational velocity for the host stars of 56 transiting planets. Our analysis is based primarily on the Stellar Parameter…
New space missions (e.g., NASA-TESS and ESA-PLATO) will perform an analysis of bright stars in large fields of the celestial sphere searching for extraterrestrial planets. Asteroseismic observations will search for exoplanet-hosting stars…
We have combined the Kepler Eclipsing Binary Catalogue with information from the HES, KIS and 2MASS photometric surveys to produce spectral energy distribution fits to over 2600 eclipsing binaries in the catalogue over a wavelength range of…
The advent of large-scale spectroscopic surveys underscores the need to develop robust techniques for determining stellar properties ("labels", i.e., physical parameters and elemental abundances). However, traditional spectroscopic methods…
Stars play a decisive role in our Universe, from its beginning throughout its complete evolution. For a thorough understanding of their properties, evolution, and physics of their outer envelopes, stellar spectra need to be analyzed by…
The field of exoplanet research has revitalized interest in M dwarfs, which have become favorite targets of Doppler and transit surveys. Accurate measurements of their basic properties such as masses, radii, and effective temperatures have…
The oscillation spectra of solar-type stars may in the not-too- distant future be used to constrain certain properties of the stars. The CD diagram of large versus small frequency separations is one of the powerful tools available to infer…
The CoRoT faint stars channel observed about 163 600 targets to detect transiting planetary companions. Because CoRoT targets are faint (11< r <16) and close to the galactic plane, only a small subsample has been observed spectroscopically.…
We combine results from interferometry, asteroseismology and spectroscopy to determine accurate fundamental parameters of 23 bright solar-type stars, from spectral type F5 to K2 and luminosity classes III to V. For some stars we can use…
We report the discovery of stars that show spectra very close to the black-body radiation. We found 17 such stars out of 798,593 stars in the Sloan Digital Sky Survey (SDSS) spectroscopic data archives. We discuss the value of these stars…
Stellar UV spectra are fundamental diagnostics of physical and magnetic properties of stars. For instance, lines like Mg II at 280 nm serve as valuable indicators of stellar activity, providing insights into the activity levels of Sun-like…
Aims: We simulate the spectra of massive binaries at different phases of the orbital cycle, accounting for the gravitational influence of the companion star on the shape and physical properties of the stellar surface. Methods: We used the…