We present preliminary results of a simultaneous X-ray/optical campaign of the proto-typical LMXB Sco X-1 at 1-10 Hz time resolution. Lightcurves of the high excitation Bowen/HeII emission lines were obtained through narrow interference filters with ULTRACAM, and these were cross-correlated with X-ray lightcurves. We find evidence for correlated

Broadband imaging of Comet 67P/Churyumov Gerasimenko has provided more data on the characterisation of the target of the ESA Rosetta Mission. The comet monitoring between r h=2.37 and r h=2.78 AU postperihelion shows a prominent dust coma which extends up to ≈ 25,000 km from the nucleus, and a long dust structure in approximately anti-tail

On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of

Recent studies of chemical abundances of secondary stars in low mass X-ray binaries have opened a new window to obtain information on the progenitors of black holes and neutron stars. Secondary stars could have captured a significant amount of the ejected matter in the supernova explosions that originated compact objects in these systems. Thus

ζ Oph, HD 149757, is an O9.5 Vnn star with a very high projected rotational velocity (v sin i ≥ 340 km s-1). It is also a classical runaway star due to its high proper motion. We perform a quantitative analysis of its optical spectrum in order to measure important observables of the star such as its mass, effective temperature, luminosity and He, C

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