Exoplanets through extreme optics: from PLATO to SHARK-NIR

In the last years, the Observatory of Padova (Istituto Nazionale di Astrofisica – Osservatorio Astronomico di Padova) and the University of Padova have been involved massively in projects dedicated to the exoplanets search, both ground, and space-based. SHARK-NIR, the acronym of “System for coronagraphy with High order Adaptive optics from R to K band – Near-Infrared”, is an instrument designed to search and characterize the young exo-planetary system and star-forming regions in the NIR domain, in coronagraphic direct imaging and spectroscopic mode. It has been selected for the 2nd generation Large Binocular Telescope (LBT) instruments, and it will take advantage of the excellent performance of the LBT adaptive optics system, which is delivering an eXtreme Adaptive Optics (XAO) correction, necessary for SHARK-NIR to achieve the best possible coronagraphic performance, which is mandatory to detect faint planets orbiting around bright stars. CHEOPS, the acronym of “CHaracterising ExOPlanet Satellite”, is the first mission dedicated to the characterization of small-size transiting planets using ultrahigh precision photometry on bright stars already known to host planets. It will allow an accurate determination of the radii of transiting planets, for which the mass has already measured from ground-based spectroscopic surveys. It will also provide precision radii for new planets discovered by the next generation of ground-based transits surveys (Neptune-size and smaller). PLATO, the acronym of “PLAnetary Transits and Oscillations of stars”, is a mission of Medium size satellites proposed for the European Space Agency in the program “Cosmic Vision”, with the target to detect and characterize exoplanets utilizing their transit on a bright star. The overall instrumental layout proposed by the Plato Payload Consortium consists of a multi-telescope concept instrument, composed by several tens of telescope units, for which it has developed an all-refractive optical solution. These devices are characterized by a very large Field of View (more than 20 degrees on one side) with an optical quality that fits most of the energy into a single sensor pixel. Such a goal can be achieved in a variety of solutions, some including aspheric elements as well. The activities concerning my Ph.D. have been exploited both in the framework of the space projects and in the field of ground instrumentation. For the PLATO project, I participated in the Assembly, Integration, and Verification (AIV) of the Telescope Optical Unit prototype, to validate the AIV procedure and the telescope optical performance in-flight conditions. Concerning SHARK, my activity has been performing optical alignment and qualification of the instrument.