We report the discovery of a detached 20-min orbital period binary white dwarf (WD). WD 0931+444 (SDSS J093506.93+441106.9) was previously classified as a WD + M dwarf system based on its optical spectrum. Our time-resolved optical spectroscopy observations obtained at the 8 m Gemini and 6.5 m MMT reveal peak-to-peak radial velocity variations of

We measured the stellar kinematics of three face-on galaxies with the aim of searching for box/peanut-shaped (B/P) bulges. These observations test and confirm that face-on B/P bulges can be recognized by two minima in the radial profile of the fourth Gauss-Hermite moment h_4 of the line-of-sight velocity distribution measured along the bar major

We present a new non-convex model of the binary asteroid (809) Lundia. A SAGE (Shaping Asteroids with Genetic Evolution) method using disc-integrated photometry only was used for deriving physical parameters of this binary system. The model of (809) Lundia improves former system's pole solution and gives the ecliptic coordinates of the orbit pole -

Context: The analysis of unresolved stellar populations demands evolutionary synthesis models with realistic physical ingredients and extended wavelength coverage. Aims: We quantitatively describe the first CO bandhead at 2.3 μm to allow stellar population models to provide improved predictions in this wavelength range. Methods: We observed a new

Helioseismic inversion techniques have been revealed as powerful tools for inferring the internal structure and dynamics of the Sun. One of the most popular techniques is Regularized Least Squares. When it is used, it is necessary to define an inversion mesh and a penalty function, without an a priori knowledge of the behaviour of the solution. In