Las binarias de rayos X son sistemas formados por un objeto compacto, ya sea un agujero negro de masa estelar o una estrella de neutrones, que absorbe (acreta) materia procedente de una estrella donante. Estos sistemas pueden clasificarse en función de su emisión en rayos X: los sistemas persistentes muestran una elevada luminosidad en rayos X de

A sub-Earth-mass planet orbiting Barnard's star, designated as Barnard b, has recently been announced. At almost the same time, the first photometric data of Barnard's star by the Transit Exoplanet Survey Satellite (TESS) was released in Sector 80. We explore the possibility of emergent transits of Barnard b in TESS photometry. The detrended 2 min

The AU Microscopii planetary system is only 24 Myr old, and its geometry may provide clues about the early dynamical history of planetary systems. Here, we present the first measurement of the Rossiter-McLaughlin effect for the warm sub-Neptune AU Mic c, using two transits observed simultaneously with the European Southern Observatory's (ESO's)

In main-sequence, low-mass (<1.3 Solar mass) stars, rotation and magnetic activity decrease over time, with the spin-down thought to be due to angular momentum lost through magnetized winds. This magnetic activity heats the stellar atmospheres, leading to the production of Hα, ultraviolet (UV), and X-ray radiation, each originating from different

We present GTC-OSIRIS phase-resolved optical spectroscopy of three compact binary millisecond pulsars, or 'spiders': PSR J1048+2339, PSR J1810+1744, and (for the first time) PSR J1908+2105. For the companion in each system, the temperature is traced throughout its orbit, and radial velocities are measured. The radial velocities are found to vary

We report the results obtained from the analysis of XMM-Newton and NuSTAR observations of two ultraluminous X-ray sources (ULXs) located in the galaxies ESO 501–023 and IC 5052. To better understand their nature, we studied the spectral and timing behavior of these sources. We used spectral-timing techniques to investigate the presence of possible