For more than six decades, the quest to understand the formation of hot (about 20,000-30,000 K) extreme horizontal branch (EHB) stars in Galactic globular clusters has remained one of the most elusive in stellar evolutionary theory. Here we report on two discoveries that challenge the idea of the stable luminosity of EHB stars. The first mode of

The black hole candidate and X-ray binary MAXI J1535-571 was discovered in 2017 September. During the decay of its discovery outburst, and before returning to quiescence, the source underwent at least four reflaring events, with peak luminosities of ∼10 35-36 erg s -1 (d/4.1 kpc) 2. To investigate the nature of these flares, we analysed a sample of

The closet exoplanets to the Sun provide opportunities for detailed characterization of planets outside the Solar System. We report the discovery, using radial velocity measurements, of a compact multiplanet system of super-Earth exoplanets orbiting the nearby red dwarf star GJ 887. The two planets have orbital periods of 9.3 and 21.8 days

High resolution transit spectroscopy has proven to be a reliable technique for the characterization of the chemical composition of exoplanet atmospheres. Taking advantage of the broad spectral coverage of the CARMENES spectrograph, we initiated a survey aimed at characterizing a broad range of planetary systems. Here, we report our observations of

In earlier works, we had shown the actual possibility that the Nabataeans had used the Equinox, or an astronomical event equivalent to this, as an important milestone to control the calendar, stablish festivals and perform pilgrimages to important sacred sites. In this paper we present evidence that this was indeed the case. In a research carried

The Sun and other similar (solar-like) stars have an internal magnetic field that can emerge on the surface, forming features such as dark spots, which drive the so-called magnetic activity. For both the Sun and solar-like stars, magnetic activity varies with time and strongly correlates with photometric (brightness) variability. In the solar and