We present Chandra and XMM-Newton X-ray observations that monitor the neutron star cooling of the quasi-persistent neutron star X-ray transients KS 1731-260 and...

Analyses of very accurate CoRoT space photometry, past Johnson V photoelectric photometry and high-resolution echelle spectra led to the determination of...

We have conducted a 3-month programme of simultaneous optical, soft and hard X-ray monitoring of the LMXB 4U 1636-536/V801 Ara using the SMARTS 1.3-m telescope...

We report simultaneous X-ray and optical observations of V404 Cyg in quiescence. The X-ray flux varied dramatically by a factor of >~20 during a 60 ks...

We present the results of a new multi-site campaign (COYOTES II) to monitor the light variations of T Tauri stars (TTS) of the Taurus-Auriga dark cloud. The...

MAXI J1659-152 is a 2.4 h orbital period X-ray dipping transient black hole candidate. We present spectroscopy of its I ≍ 23 quiescent counterpart, where we...

Ultra Luminous X-ray Sources (ULXs) are extragalactic X-ray point sources with L_X ˜ 10^39-10^41 erg s^-1 discovered in the 80s with the Einstein satellite and...

We present high speed optical photometric observations made using the NTT and ULTRACAM of the optical counterpart of 3XMMJ051034.6-670353, which was recently...

Aims: We present a multiwavelength study of the Be/X-ray binary system XTE J1946+274 with the main goal of better characterizing its behavior during X-ray...