Subsolar metallicity L subdwarfs was discovered over a decade ago, but remain poor understood due to lack of known objects. We started to search for L subdwarfs since a few years ago and have increased the number of known L subdwarfs from 23 to 57. We are following up 33 L subdwarfs with X-shooter on the Very Large Telescope. We are also measuring

The oxygen abundance in the solar photosphere, and consequently the solar metallicity itself, is still a controversial question with far-reaching implications in many areas of astrophysics. This paper presents a new determination obtained by fitting the forbidden O i line at 6300 Å with an observational 3D model. The approach presented here is

QUIJOTE (Q-U-I JOint TEnerife) is a new polarimeter aimed to characterize the polarization of the Cosmic Microwave Background and other Galactic and extragalactic signals at medium and large angular scales in the frequency range 10--40 GHz. The multi-frequency (10--20 GHz) instrument, mounted on the first QUIJOTE telescope, saw first light on

The PLATO 2.0 space mission (PLAnetary Transits and Oscillation of stars) was selected by the ESA Science Programme in February 2014, as the M3 mission to be launched in 2024. PLATO 2.0 will detect terrestrial exoplanets in the habitable zone of bright solar-type stars and characterise their bulk properties. The exoplanets will be detected by the

Some cities were built with the idea of establishing cosmic order. The sky used to be a very important component of the landscape that has been lost completely in our modern, overcrowded and excessively illuminated cities. However, this was not the case in the past. Astronomy actually played a most relevant role in urban planning, particularly in