 PLATO PLAnetary Transits & Oscillations of stars

1. beyond CoRoT & Kepler http://www.lesia.obspm.fr/cosmicvision/plato  PLATO PLAnetary Transits & Oscillations of stars Next generation mission for ultra-high precision stellar photometry Search for and characterisation of exoplanets + asteroseismology Class-M mission under assessment study at ESA in the framework of « Cosmic Vision » programme

2. The science objectives of PLATO PLAnetary Transits & Oscillations of stars main objective : evolution of exoplanetary systems (= planets + host stars) - the evolution of planets and that of their host stars are intimately linked - a complete & precise characterisation of host stars is necessary to measure exoplanet properties: mass, radius, age compare planetary systems at various stages of evolution correlation of planet evolution with that of their host stars = comparative exoplanetology Three kinds of observables : 1. detection & characterisation of planetary transits 2. seismic analysis of exoplanet host stars 3. complementary ground based follow-up (spectroscopy) seismic analysis - R*, M*, age - interior transit detection - Porb, Rp/R*, R*/a spectro, RV, G/B photometry, imaging,… - exoplanet confirmation - Mp/M*2/3 - chemical composition of host stars - … and of exoplanet atmospheres

3. high level science requirements - P1: > 20,000 bright (~ mV≤11) cool dwarfs (>F5V); noise < 27 ppm in 1hr - P2: > 80,000 bright cool dwarfs; noise < 80 ppm in 1hr during long pointing but < 27 ppm in 1 hr during step & stare phase - P3: ~ 1000 very bright stars (4 ≤mV≤ 8) for 3 years: asteroseismology of specific targets - P4: ~ 3000 very bright stars (4 ≤mV≤ 8) for > 5 months: asteroseismology + planet search - P5: > 250,000 cool dwarfs; noise < 80 ppm in 1 hr for 3 years - very long monitoring ≥ 3 years - very high duty cycle ≥ 95% = 1 ppm in 30 d = req. seismic analysis = req. for 1Rearth Scientific Requirements main science objectives - detection and study of Earth-analogsystems - exoplanets around the brightest stars, all sizes, all orbital periods - full characterisation of planet host stars, via seismic analysis

4. Main Instrument Requirements - very wide field: > 550 deg2 (CoRoT: 4 deg2; Kepler: 100 deg2) - 2 successive fields (2 x 3y) + step & stare phase (1y: e.g. 4 fields x 3 months) - large collecting area - very low instrumental noise, in particular satellite jitter ≤ 0.2 arcsec requirements for ground- and space-based follow-up - high precision radial velocity measurements: false-alarm elimination, masses - high resolution spectroscopy: chemical composition - differential spectroscopy: exoplanet atmosphere composition

5. The PLATO study organization ESA study scientist, study manager, payload manager M. Fridlund R. Lindberg D. Lumb ESA PSST PLATO Consortium Council 2 industrial contractors Payload + SVM PPLC = PLATO Payload Consortium PSC = PLATO Science Consortium PI: D. Pollacco Co-Pis: G. Piotto H. Rauer S. Udry PI: C. Catala Co-Pi: M. Deleuil study of payload system telescopes/optics FPA onboard data processing ground data centre science case scientific preparation field characterisation and choice follow-up observations

6. The PPLC Payload concept - fully dioptric design - 11cm pupil, 28°x28° field - FPA: 4 CCDs 35842, 18 - 40 normal telescopes: full frame CCDs cadence 25s 8 ≤ mV ≤ 14 - 2 « fast » telescopes: frame transfer CCDs cadence 2.5s 4 ≤ mV ≤ 8 - overlapping line-of-sight concept - 2 long pointings (3 yrs) - 1 yr step & stare injection into large Lissajous L2 orbit continuous observation, field rotation every 3 months

7. Performance of PPLC baseline design magnitude for noise 27 ppm in 1 hr highest priority requirement: > 20,000 cool dwarfs with noise < 27 ppm in 1 hr performance of initial industrial design, now being improved

8. Performance of PPLC baseline design

9. Performances planets down to 1 Rearth around late-type stars with mV≤12-13 (>300,000 stars; incl. 60,000 with potential seismic analysis ) planets down to 0.6 Rearth around G-type stars with mV=9.6-11.1 with seismic analysis (26,500 stars) transit depth detected at 3  if duration = 10h telluric planets around stars up to A-type with mV=9.6-11.1

10. 40 « normal » telescopes 2 « fast » telescopes mV = 10.5 30,000 stars 3 years Performances

11. Conclusion PLATO will provide: a complete and unbiased database to understand the evolution of stars and their planets PLATO will bring us: - complete characterization of large number of exoplanets (size, mass, age) - improvement of exoplanet statistics - correlation planetary versus stellar evolution - decisive progress in stellar evolution modelling PLATO needs strong support: - from « exoplanet » community - from « stellar » community - fall 2009: down-selection for definition phase - 2011: final selection for flight