Related papers: The fundamental parameters of the roAp star alpha …

We report new interferometric angular diameter observations of 41 carbon stars observed with the Palomar Testbed Interferometer (PTI). Two of these stars are CH carbon stars and represent the first such measurements for this subtype. Of…

We conducted high dispersion spectroscopic observations of 50 superflare stars with Subaru/HDS, and measured the stellar parameters of them. These 50 targets were selected from the solar-type (G-type main sequence) superflare stars that we…

We compare the first direct angular diameter measurements obtained on our closest stellar neighbour, Alpha Centauri, to recent model diameters constrained by asteroseismic observations. Using the VINCI instrument installed at ESO's VLT…

In the current era of Gaia and large, high signal to noise stellar spectroscopic surveys, there is an unmet need for a reliable library of fundamentally calibrated stellar effective temperatures based on accurate stellar diameters. Here we…

In this paper we present and analyse determinations of effective temperatures of planet-hosting stars using infrared (IR) photometry. One of our goals is the comparison with spectroscopic temperatures to evaluate the presence of systematic…

We present two new rapidly oscillating Ap (roAp) stars, TIC 198781841 and TIC 229960986, discovered in TESS photometric data. The periodogram of TIC 198781841 has a large peak at 166.506 d$^{-1}$ (1.93 mHz), with two nearby peaks at 163.412…

The radio spectra of main-sequence stars remain largely unconstrained due to the lack of observational data to inform stellar atmosphere models. As such, the dominant emission mechanisms at long wavelengths, how they vary with spectral…

High quality 4500-6800 A spectropolarimetric observations of the Circinus galaxy are reported. These show polarized and relatively broad (FWHM~3300 km/s) Halpha (as well as marginal Hbeta) arising from a <3" (<60 pc) region centered on the…

We report the identification of 61.45 d^-1 (711.2 mu Hz) oscillations, with amplitudes of 62.6-mu mag, in KIC 4768731 (HD 225914) using Kepler photometry. This relatively bright (V=9.17) chemically peculiar star with spectral type A5 Vp…

We aim at resolving the circumstellar environment around beta Pic in the near-infrared in order to study the inner planetary system (< 200 mas, i.e., ~4 AU). Precise interferometric fringe visibility measurements were obtained over seven…

W Serpentis is an eclipsing binary system and the prototype of the Serpentid class of variable stars. These are interacting binaries experiencing intense mass transfer and mass loss. However, the identities and properties of both stars in W…

The precise mechanisms that provide the non-radiative energy for heating the chromosphere and the corona of the Sun and other stars are at the focus of intense contemporary research. Observations at submm/mm wavelengths are particularly…

We undertook a time-series photometric multi-site campaign for the rapidly oscillating Ap star HD 99563 and also acquired mean light observations over two seasons. The pulsations of the star, that show flatter light maxima than minima, can…

BS Cir is a representative of moderately cool magnetic chemically peculiar stars which displays very strong light variations in Stroemgren index c1 indicating large changes in the height of the Balmer jump. We present two-spot model of…

The photospheric radius is one of the fundamental parameters governing the radiative equilibrium of a star. We report new observations of the nearest solar-type stars Alpha Centauri A (G2V) and B (K1V) with the VLTI/PIONIER optical…

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…

Accurate stellar parameters are needed in numerous domains of astrophysics. The position of stars on the H-R diagram is an important indication of their structure and evolution, and it helps improve stellar models. Furthermore, the age and…

$\theta$ Cygni is an F3 spectral-type main-sequence star with visual magnitude V=4.48. This star was the brightest star observed by the original Kepler spacecraft mission. Short-cadence (58.8 s) photometric data using a custom aperture were…

Understanding the physical process responsible for the transport of energy in the core of $\alpha$ Centauri A is of the utmost importance if this star is to be used in the calibration of stellar model physics. Adoption of different parallax…

The determination of fundamental parameters of stars is one of the main tasks of astrophysics. For magnetic chemically peculiar stars, this problem is complicated by the anomalous chemical composition of their atmospheres, which requires…