The study of primitive asteroids has gained much momentum in the last decade. The term "primitive" usually refers to objects with spectral characteristics similar to those of the carbonaceous chondrites, the most primitive meteorites. These meteorites contain pristine materials that have undergone very little processing since their formation, some

We present the study of the metallicity dependence of the Fourier amplitude ratios R21 and R31 for the light curves of short-period Galactic classical Cepheids in B, V, RC and IC bands. Based on the available photometric and spectroscopic data, we determined the relations between the atmospheric iron abundance, [Fe/H], and the Fourier parameters

Context. Variability is a general property of active galactic nuclei (AGN). The way in which these changes occur at X-rays is not yet clearly understood. In the particular case of low-ionization nuclear emission line region (LINER) nuclei, variations on the timescales from months to years have been found for some objects, but the main driver of

Context. Standard stellar evolution theory does not predict existence of Li-rich giant stars. Several mechanisms for Li-enrichment have been proposed to operate at certain locations inside some stars. The actual mechanism operating in real stars is still unknown. Aims: Using the sample of 348 stars from the Penn State - Toruń Centre for Astronomy

We investigate the internal structure and density profiles of halos of mass $10^{10}-10^{14}~M_\odot$ in the Evolution and Assembly of Galaxies and their Environment (EAGLE) simulations. These follow the formation of galaxies in a $\Lambda$CDM Universe and include a treatment of the baryon physics thought to be relevant. The EAGLE simulations

The resonant scattering solar spectrophotometer `Mark-I', designed and build at the University of Birmingham (UK) and located at the Observatorio del Teide (Spain), has been continuously in operation for the past 38 years. During this period of time, it has provided high-precision measurements of the radial velocity of the Sun as a star, which has