Umbral flashes are sudden brightenings commonly visible in the core of some chromospheric lines. Theoretical and numerical modeling suggests that they are produced by the propagation of shock waves. According to these models and early observations, umbral flashes are associated with upflows. However, recent studies have reported umbral flashes in downflowing atmospheres. We aim to understand the origin of downflowing umbral flashes. We explore how the existence of standing waves in the umbral chromosphere impacts the generation of flashed profiles. We performed numerical simulations of wave

The black holes at the centres of galaxies are the most mysterious objects in the Universe, not only because of the huge quantities of material within them, millions of times the mass of the Sun, but because of the incredibly dense concentration of matter in a volume no bigger than that of our Solar System. When they capture matter from their surroundings they become active, eventually giving rise to the ejection of huge amounts of energy. It is however difficult to detect the black hole during these capture episodes because the event is rare. We detected long and narrow dust filaments

We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. The planet Gliese 486 b is 2.81 Earth masses and 1.31 Earth radii, a composition similar to that of Venus or Earth, as determined from exquisite radial velocity data and photometric light curves. The host star is at a distance of 26 light-years, very bright, and observable from both hemispheres of Earth. The stellar and planet properties indicate that despite the hot surface temperatures it is possible that the planet conserved part of its original atmosphere, making it an