We present a study of the X-ray flaring activity of Sgr A⋆ during all the 150 XMM-Newton and Chandra observations pointed at the Milky Way centre over the last 15 years. This includes the latest XMM-Newton and Chandra campaigns devoted to monitoring the closest approach of the very red Brγ emitting object called G2. The entire data set analysed

The photospheric temperature minimum in the Sun and solar-like stars is very weakly ionized, with an ionization fraction f as low as 10‑4. In galactic star-forming regions, f can be 10‑10 or lower. Under these circumstances, the Hall current can couple low-frequency Alfvén and magnetoacoustic waves via the dimensionless Hall parameter ε =ω /{{{Ω }}

We analyzed the near-infrared to UV data of 16 quasars with redshifts ranging from 0.71

Our group is presently conducting an observational campaign, using the 10-meter Gran Telescopio Canarias (GTC), to obtain the transmission spectrum of several exoplanets during a transit event. The GTC instrument OSIRIS is used in its long-slit spectroscopic mode, covering the spectral range of 520-1040 nm, and observations are taken using a set of

The inner Galactic bulge has, until recently, been avoided in chemical evolution studies because of extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such as the Apache Point Observatory Galactic Evolution Experiment (APOGEE), for the first time allow the measurement of metallicities in the inner region of our Galaxy

The amplitudes of the Evershed flow are measured using pairs of carefully selected Fe i and Fe ii spectral lines that are close in wavelength and registered simultaneously. A sunspot belonging to the NOAA 11582 group was scanned using the spectrograph of the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife). Velocities were extracted