We report the discovery of a group of apparently young CoRoT red-giant stars exhibiting enhanced [α/Fe] abundance ratios (as determined from APOGEE spectra) with respect to solar values. Their existence is not explained bystandard chemical evolution models of the Milky Way, and shows that the chemical-enrichment history of the Galactic disc is more

Magnetic waves are a relevant component in the dynamics of the solar atmosphere. Their significance has increased because of their potential as a remote diagnostic tool and their presumed contribution to plasma heating processes. We discuss our current understanding of coronal heating by magnetic waves, based on recent observational evidence and

The atmospheric Precipitable Water Vapour content (PWV) is crucial for astronomical observations in the infrared. In this work, we have validated the Weather Research and Forecasting (WRF) mesoscale numerical model as an operational tool for PWV at Roque de los Muchachos astronomical Observatory (ORM). We used radiosonde data obtained directly at

Quantitative seeing measurements have been provided at the Canarian Observatories since 1990 by differential image motion monitors (DIMMs). Image quality needs to be studied in long term (routine) measurements. This is important, for instance, in deciding on the siting of large telescopes or in the development of adaptive optics programmes, not to

Probing the magnetism of the upper solar chromosphere requires measuring and modeling the scattering polarization produced by anisotropic radiation pumping in UV spectral lines. Here we apply PORTA (a novel radiative transfer code) to investigate the hydrogen Lyα line in a three-dimensional model of the solar atmosphere resulting from a state of

We present three giant stars from the ongoing Penn State–Toruń Planet Search with the Hobby–Eberly Telescope, which exhibit radial velocity (RV) variations that point to the presence of planetary-mass companions around them. BD+49 828 is a M=1.52+/- 0.22 {{M}ȯ } K0 giant with a m sin i=1.6-0.2+0.4 {{M}J} minimum mass companion in a = 4.2+0.32‑0.2