Models predict that planets with water-rich compositions may be common around low-mass stars, but definitive evidence for the existence of water worlds has remained elusive. Precise mass and radius measurements for small planets allow us to identify candidate water worlds that have bulk densities too low to be consistent with a rocky composition

Aims: We have performed the first broadband study of Mrk 421 from radio to TeV gamma rays with simultaneous measurements of the X-ray polarization from IXPE. Methods: The data were collected as part of an extensive multiwavelength campaign carried out between May and June 2022 using MAGIC, Fermi-LAT, NuSTAR, XMM-Newton, Swift, and several optical

NIRPS is a new fiber-fed high spectral resolution (~80k) spectrograph assisted by adaptive optics installed on the 3.6m telescope of ESO at LaSilla, Chile. Operated simultaneously with HARPS, NIRPS covers the Y, J, and H bands. The commissioning phase demonstrated high stability for time-series observations along precise radial velocities reaching

The study of the rare decays B →K (*)ν ν ¯ offers a window into the dynamics operating at the electroweak scale, allowing studies of the Standard Model and searches for heavy new physics. However, the analysis of these decays is also potentially sensitive to the on shell production of new light bosons X through the process B →K (*)X . In particular

Context. In recent years, a number of Lyman continuum (LyC) leaker candidates have been found at intermediate redshifts, providing insight into how the Universe was reionised at early cosmic times. There are now around 100 known LyC leakers at all redshifts, which enables us to analyse their properties statistically. Aims: Here, we identify new LyC

Over the past three decades, astronomers have discovered that small, rocky planets in temperate orbits are common around our neighboring stars. Whether or not these planets can maintain atmospheres is an open question in the field. Recently, considerable attention in this search has been focused on M dwarfs stars, as their small sizes make it