PLATO 2.0 (PLAnetary Transits and Oscillations of stars) has recently been selected for European Space Agency’s (ESA) M3 launch opportunity (2022/24). It is a medium class mission within the framework of the ESA Cosmic Vision 2015-2025 program. PLATO 2.0 will discover many potentially habitable planets. Presently, more than 1700 exoplanets with secure identifications are known and many others are unconfirmed planet candidates. PLATO 2.0 consists of 32 telescopes operating in white light and two additional fast cameras with colour filters. This multi-telescope design will allow a large photometric dynamic range. The mission lifetime will be 6 years, with a possible extension of 2 years. In total, about 50% of the sky will be covered.
The involvement of our country, especially in the fields of electronic systems and optics, is very relevant. The Italian contribution is funded by the Italian Space Agency (ASI), which also provides a segment of the PLATO Data Center, managed by the ASI Science Data Center (ASDC). Italian researchers contribute to the PLATO Mission Consortium, providing the scientific coordination of two important elements of the Payload – the Telescope Optical Units (TOUs) and the Instrument Control Unit (ICU) – and participating to the Science Preparation Management (PSPM), i.e., the activities required for the preparation of the scientific programme and the assessment of the mission performance. Almost a hundred of Italian scientists, mainly working at the National Institute for Astrophysics (INAF), are involved in the project.
Dr. Pagano, what are the main Italian research centres involved? What are their duties and responsibilities?
The Italian collaboration includes several INAF research institutes, together with the Universities of Padua and Florence. Roberto Ragazzoni (INAF Padua) is the scientist responsible for the delivery to the PMC of the opto-mechanics of the 34 telescopes, the so-called TOUs. His team includes scientists and engineers from INAF Padua, Catania and Milan. In Catania we are doing the analysis of the scattered light inside the telescope and the TOU project management, in which I am involved personally. The INAF Brera (Milan) contributes the thermal and optical materials analysis, while INAF Padua is responsible for the optical design, the system engineering, the design of the integration and testing procedures and carries out all the necessary prototyping activities. The Instrument Control Unit, i.e., the on-board computers devoted to process and compress digital data inputs, will be delivered to the PMC under the responsibility of Rosario Cosentino (INAF, Telescopio Nazionale Galileo), who coordinates a team based at INAF Rome and University of Florence.
From the scientific point of view, Giampaolo Piotto, the second Italian member of the PMCB, is now coordinating the important selection of the stellar fields and the individual targets to be observed. Together with Roberto Ragazzoni, he will also be appointed in the PLATO Science Team. Many scientific contributions to PLATO preparation will be possible thanks to all the INAF research institutes. For example, here in Catania we will study the stellar activities, which can influence the signal we want to measure.
What is the contribution of ASI, not only economically, compared to that of other European countries?
The TOUs and ICU are very important parts of the Payload. These will be contracted to companies selected by ASI. Together with the ASDC involvement in the PLATO Data Center, the whole ASI contribution makes our country one of the three main partners of the PMC with Germany and France.
For the youngest Italian astronomers, how important is the participation in this wide-ranging project together with their European colleagues?
The participation of young people, such as graduate students and post-docs, is very important in all stages of the project. They will be involved during the definition and implementation phases, and after the launch when data will arrive, and they will be both scientists and engineers. In addition, the data will be available to the whole scientific community, not only to us preparing the mission, as soon as they will be validated scientifically. Only a small fraction of the sample will be of exclusive competence of the Consortium, about 1000 stars, but only for one year. In addition, the data will be also used for many stellar physics research projects.
Will there be some exchange programs between the astronomers of the involved countries?
Yes, this is already the case, for example during the doctorate. In any case, working remotely in Europe is now a daily activity, almost as if we were all in a sort of permanent meeting. Normally, I work on the management from Catania, but most of the group's members are in Padua. From this point of view, the technology is very useful and it makes possible our operations at a European level.