Context: We study the chromosphere of an active region of the Sun in the Hα line. Aims: The development of new instrumentation and new methods of data analysis...

The black hole transient GRS 1915+105 entered a new phase of activity in 2018, generally characterised by low X-ray and radio fluxes. This phase has only been...

The principal components analysis (PCA) technique is used to develop an extremely fast and stable Stokes inversion code, suitable for application to large data...

Context. WASP-127b is a planet with one of the lowest densities discovered to date. With a sub-Saturn mass (Mp = 0.18 ± 0.02 MJ) and super-Jupiter radius (Rp =...

Context. Exoplanet atmospheres are the key to understanding the nature of exoplanets. To this end, transit spectrophotometry provides us opportunities to...

We present the discovery of 15 new T2.5-T7.5 dwarfs (with estimated distances ~24-93pc), identified in the first three main data releases of the United Kingdom...

Lyα emitter (LAE) surveys have successfully used the excess in a narrowband filter compared to a nearby broadband image to find candidates. However, the odd...

Studying the earliest stages in the birth of stars is crucial for understanding how they form. Brown dwarfs with masses between that of stars and planets are...

We report on the detection of linear polarization of the forbidden [O i] 630.03 nm spectral line. The observations were carried out in the broader context of...