Context. Interpreting the Stokes profiles observed in quiet regions of the solar chromosphere is a challenging task. The Stokes Q and U profiles are dominated by the scattering polarisation and the Hanle effect, and these processes can only be correctly quantified if 3D radiative transfer effects are taken into account. Forward-modelling of the

HST/ACS observations along the major axis of M33 show that the mean age of its stars decreases with increasing distance from the galaxy centre. Such a behaviour is consistent with an inside-out growth of the disc. However, in the outermost observed field, at r ≃ 11.6 kpc, a reversal of this gradient is detected, with old stars found in high

We obtained climate normals over a period of 10 years (2003–2012) at Izaña (2395 m), Tenerife (Spain) with the aim of characterizing the mesoscale climate conditions governing the two astronomical observatories in the Canary Islands: Teide Observatory, located on the summit of Izaña and Roque de los Muchachos Observatory (ORM), approximately 140 km

We present chemical abundance determinations of two H II regions in the dwarf irregular (dIrr) galaxy Leo A from Gran Telescopio Canarias (GTC) Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) long-slit spectra. Both H II regions are of low excitation and seem to be ionized by stars later than O8V spectral type. In one

We report the discovery of an additional substellar companion in the CoRoT-20 system based on six years of HARPS and SOPHIE radial velocity follow-up. CoRoT-20 c has a minimum mass of 17 ± 1 MJup and orbits the host star in 4.59 ± 0.05 yr, with an orbital eccentricity of 0.60 ± 0.03. This is the first identified system with an eccentric hot Jupiter

We report on the results of optical, near-infrared (NIR), and mid-infrared observations of the black hole X-ray binary candidate (BHB) MAXI J1535–571 during its 2017/2018 outburst. During the first part of the outburst (MJD 58004–58012), the source shows an optical–NIR spectrum that is consistent with an optically thin synchrotron power law from a