Mass, radius and age are three of the most fundamental parameters for celestial objects, enabling insight into the evolution and internal physics of stars, brown dwarfs and planets. Brown dwarfs are hydrogen-rich objects that are unable to sustain core fusion reactions but are supported against collapse by electron degeneracy pressure 1. As they

White dwarfs are dense, cooling stellar embers consisting mostly of carbon and oxygen 1, or oxygen and neon (with a few per cent carbon) at higher initial stellar masses 2. These stellar cores are enveloped by a shell of helium, which in turn, is usually surrounded by a layer of hydrogen, generally prohibiting direct observation of the interior

It has long been suspected that tidal forces in close binary stars could modify the orientation of the pulsation axis of the constituent stars. Such stars have been searched for, but until now never detected. Here we report the discovery of tidally trapped pulsations in the ellipsoidal variable HD 74423 in Transiting Exoplanet Survey Satellite

Ly α emission lines are typically found to be redshifted with respect to the systemic redshifts of galaxies, likely due to resonant scattering of Ly α photons. Here, we measure the average velocity offset for a sample of 96 z ≍ 3.3 Ly α emitters (LAEs) with a median Ly α flux (luminosity) of ${\approx}10^{-17}~\rm erg~cm^{-2}~s^{-1}$ ( ${\approx}10

We determine the inner density profiles of massive galaxy clusters (M 200 > 5 × 10 14 M ☉) in the Cluster-EAGLE (C-EAGLE) hydrodynamic simulations, and investigate whether the dark matter density profiles can be correctly estimated from a combination of mock stellar kinematical and gravitational lensing data. From fitting mock stellar kinematics

Ultracompact accreting binary systems each consist of a stellar remnant accreting helium-enriched material from a compact donor star. Such binaries include two related sub-classes, AM CVn-type binaries and helium cataclysmic variables, in both of which the central star is a white dwarf. We present a spectroscopic and photometric study of six