The Saturn-mass exoplanet WASP-39b has been the subject of extensive efforts to determine its atmospheric properties using transmission spectroscopy 1-4. However, these efforts have been hampered by modelling degeneracies between composition and cloud properties that are caused by limited data quality 5-9. Here we present the transmission spectrum

Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories. Transmission spectroscopy (for example, refs. 1,2) provides the necessary means by constraining the abundances of oxygen-

Lyman-break galaxy (LBG) candidates at z ≳ 10 are rapidly being identified in James Webb Space Telescope (JWST)/NIRCam observations. Due to the (redshifted) break produced by neutral hydrogen absorption of rest-frame UV photons, these sources are expected to drop out in the bluer filters while being well detected in redder filters. However, here we

In this Letter, we revisit the relationship between the fraction of the intra-cluster light (ICL) as well as the virial mass and the fraction of early-type galaxies in the host halo. This exploration is based on a statistically significant and homogeneous sample of 22 groups and clusters of galaxies in the Local Universe (z ≤ 0.05), obtained with

Context. The γ-ray emitting source WISE J141046.00+740511.2 has been associated with a Fermi-LAT detection by crossmatching with Swift/XRT data. It has shown all the canonical observational characteristics of a BL Lac source, including a power-law, featureless optical spectrum. However, it was only recently detected at radio frequencies and its

The heart of this thesis is the multiwavelength (MWL) study of a special subclass of active galactic nuclei (AGN) called blazars. These objects host a supermassive black hole as their central engine. They present a relativistically boosted jet that points towards the Earth, acting as a natural particle accelerator, emitting over the entire