The Chiaravalle Cross: Results of a Multidisciplinary Study

The Chiaravalle Cross, a masterpiece of Mediaeval goldsmithery, went under restoration in 2016. This was a unique opportunity to undertake an in-depth multidisciplinary study. Several issues were addressed, as for example the chronology of the Cross, lacking any official document about it. The scientific investigations included in situ and laboratory measurements, and the analyses, part of a multidisciplinary protocol, completely characterized the gemstones adorning the Cross, the cameos, the gold, silver, jasper and glass parts, to derive indications on their provenance, authenticity and dating issues. All the results were shared with the whole collaboration of experts, which included art historians, a restorer, a conservator, a scholar in ancient glyptic, gemologists, archaeometallurgists, physicists and scientists in a very fruitful exchange of knowledge. This work is an example of a real multidisciplinary research, gathering good practices in the study of a complex piece of art

A comparison between the opto-thermo-mechanical model and lab measurements for CHEOPS

CHEOPS is the first small class mission adopted by ESA in the framework of the Cosmic Vision 2015-2025. Its launch is foreseen in early 2019. CHEOPS aims to get transits follow-up measurements of already known exo-planets, hosted by near bright stars (V<12). Thanks to its ultra-high precision photometry, CHEOPS science goal is accurately measure the radii of planets in the super-Earth to Neptune mass range (1<Mplanet/MEarth<20). The knowledge of the radius by transit measurements, combined with the determination of planet mass through radial velocity techniques, will allow the determination/refinement of the bulk density for a large number of small planets during the scheduled 3.5 years life mission. The instrument is mainly composed of a 320 mm aperture diameter Ritchey-Chretien telescope and a Back End Optics, delivering a de-focused star image onto the focal plane. In this paper we describe the opto-thermo-mechanical model of the instrument and the measurements obtained during the opto-mechanical integration and alignment phase at Leonardo company premises, highlighting the level of congruence between the predictions and measurements