We present optical spectroscopy and optical and infrared photometry of the neutron star soft X-ray transient Aql X-1 during its X-ray outburst of 1997 August...

We demonstrate that low-resolution CaII triplet (CaT) spectroscopic estimates of the overall metallicity ([Fe/H]) of individual red giant branch (RGB) stars in...

Solar pores are active regions with large magnetic field strengths and apparent simple magnetic configurations. Their properties resemble the ones found for the...

From an analysis of absorption lines in the high-resolution spectra, we have derived the radial velocities, stellar parameters (T eff, log g, wind-strength...

CHEOPS (CHaracterising ExOPlanet Satellite) is an ESA S-class mission that observes bright stars at high cadence from low-Earth orbit. The main aim of the...

We present spatially resolved Keck Cosmic Web Imager stellar spectroscopy of the Virgo cluster dwarf galaxies VCC 9 and VCC 1448. These galaxies have similar...

The study of planetary nebulae provides important constraints for many aspects of stellar and Galactic evolution. Hen 2-108 is a poorly known planetary nebula...

Polar faculae are bright features that can be detected in solar limb observations and they are related to magnetic field concentrations. Although there are a...

The scatter in the galaxy size versus stellar mass (M ⋆) relation gets largely reduced when, rather than the half-mass radius R e, the size at a fixed surface...