G. Micela – Bologna 5/03/2009  PLATO in the context of the extrasolar planet research Giusi Micela (INAF-OAPa)

G. Micela – Bologna 5/03/2009 Outline Cosmic Vision context Relevance of transits for extrasolar planet search PLATO contribution Beyond PLATO

G. Micela – Bologna 5/03/2009 Cosmic Vision On 18 October 2007, ESA selected for an Assessment Study 6 M-class and 3 L-class candidate mission concepts resulting from the first Call for Mission for the Cosmic Vision plan. These mission concepts are competing for launch opportunities in 2017/2018. down-selection for definition phase for M-class missions in fall 2009 final selection for flight of M-class mission in 2011

G. Micela – Bologna 5/03/2009 M-class missions Solar mission Space Plasmas NEO Dark energy (Dune + Space) Infrared (Japan) Extrasolar planets

G. Micela – Bologna 5/03/2009 Known exoplanets 316 planets in 270 systems, Oct Feb 2009 from RV searches. 33 multiple systems. 57 Transiting planets 7 from microlensing surveys. + a few others

G. Micela – Bologna 5/03/2009 Left panel: Core accretion+migration simulations by Ida & Lin (2004), showing gas giants, ice giants, rocky planets. around solar-like stars Right panel: Radial-velocity discovered planets. ESP population synthesis

G. Micela – Bologna 5/03/2009 Planetary search methods domains Transits due to Earth-like planets can be detected with accurate (10 -4 ) photometric searches.  only from space

G. Micela – Bologna 5/03/2009 New planets are continuously discovered. The number of new discovered transits is quickly increasing (~2/3 in the last two years)

G. Micela – Bologna 5/03/2009 Transits For an edge-on orbit, transit duration is: –  t ≈ (PR * ) / (  a) P=period, a=semi-major axis of orbit Probability of transit –P transit ≈ R * / a –For Earth (P=1yr, a=1AU), P transit =0.5% –But for close, “hot” Jupiters, P transit =10% –Of course, to detect Earths at 1 AU we need to monitor the star for up to 1 year

G. Micela – Bologna 5/03/2009 Transits Advantages –Easy. Can be done with small, cheap telescopes –Possible to detect low mass planets, including “Earths”, especially from space Disadvantages –Probability of seeing a transit is low Need to observe many stars simultaneously –Easy to confuse with starspots, binary/triple systems –Needs radial velocity measurements for confirmation, masses

G. Micela – Bologna 5/03/2009 Transits Radial velocity + Transits Porb, dist, mass, radius, density, inclination Transits from ground  Jupiters Transits from space  Earths

G. Micela – Bologna 5/03/2009 Radial velocity follow up are needed to determine the properties of transit discovered planets Critical point. Transits from space may now detect earth-size planets  bottle neck due to limiting vrad measurement capabilities. We need to measure ~cm/sec Very stable spectroscopes, new generation telescopes

G. Micela – Bologna 5/03/2009 We need also to know very well the host properties  R pl = f(R * )  M pl = f(M * ) age = age * Bright stars!!

G. Micela – Bologna 5/03/2009 Observational properties Mass distribution for vrad-discovered planet (upper) and transiting planets (lower)

G. Micela – Bologna 5/03/2009 Observational properties Orbital distance distribution for vrad- discovered planet (upper) and transiting planets (lower)

G. Micela – Bologna 5/03/2009 The first space transit mission: CoRoT French mission with ESA contribution Launch Dec. 2006, extension of 3 years more Extrasolar planets and asteroseismology Six planets already discovered Many candidates Very long follow up phase

G. Micela – Bologna 5/03/2009 Convection Rotation and planetary Transits - CoRoT 6 planets EXO-2 orbiting a young active star EXO-3 high mass, compact object EXO-7 – rocky (2xR(Earth)) with P~0.85d A&A Cover Wide field telescope (27cm aperture) with 4 deg field. Most stars from Mag.

G. Micela – Bologna 5/03/2009 Convection Rotation and planetary Transits - CoRoT A&A Cover Wide field Planetary transits

G. Micela – Bologna 5/03/2009  PLATO PLAnetary Transits & Oscillations of stars Search for and characterisation of exoplanets + asteroseismology Class-M mission under assessment study at ESA in the framework of « Cosmic Vision » programme Next generation mission for ultra-high precision stellar photometry beyond CoRoT & Kepler

G. Micela – Bologna 5/03/2009 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 1.compare planetary systems at various stages of evolution 2.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) transit detection - P orb, R p /R *, R * /a spectrum, RV, photometry, imaging,… - exoplanet confirmation - chemical composition of host stars - … and of exoplanet atmospheres seismic analysis - R *, M *, age - interior

G. Micela – Bologna 5/03/2009 Scientific Requirements main science objectives - detection and study of Earth-analog systems - exoplanets around the brightest stars, all sizes, all orbital periods - full characterisation of planet host stars, via seismic analysis high level science requirements -P1: > 20,000 bright (~ m V ≤11) cool dwarfs (>F5V) with precise and reliable characterization including seismic analysis. We expect ~ 20 Earths -P2: > 80,000 bright cool dwarfs; detection of planets in the long runs and seismic analysis during step & stare phase - P3: ~ 1000 very bright stars (4 ≤ m V ≤ 8): targets for future instruments - P4: ~ 3000 very bright stars (4 ≤ m V ≤ 8): asteroseismology along the HR diagram -P5: > 250,000 cool dwarfs; planets without stellar seismic analysis

G. Micela – Bologna 5/03/2009 Scientific Requirements high level science requirements -P1: > 20,000 bright (~ m V ≤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 ≤ m V ≤ 8) for 3 years: asteroseismology of specific targets - P4: ~ 3000 very bright stars (4 ≤ m V ≤ 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 1R earth

G. Micela – Bologna 5/03/2009 Main Instrument Requirements - very wide field: > 550 deg 2 (CoRoT: 4 deg 2 ; Kepler: 100 deg 2 ) - 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

G. Micela – Bologna 5/03/2009 The PLATO study organization PLATO Consortium Council 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 ESA study scientist, study manager, payload manager M. Fridlund R. Lindberg D. Lumb ESA PSST 2 industrial contractors Payload + SVM study of payload system telescopes/optics Focal Plane onboard data processing ground data centre science case scientific preparation field characterisation and choice follow-up observations

G. Micela – Bologna 5/03/2009 The PPLC Payload concept - fully dioptric design - 11cm pupil, 28°x28° field - FPA: 4 CCDs , 18  - 40 normal telescopes: full frame CCDs cadence 25s 8 ≤ m V ≤ « fast » telescopes: frame transfer CCDs cadence 2.5s 4 ≤ m V ≤ 8 - overlapping line-of-sight concept - 2 long pointings (3 yrs) - 1 yr step & stare continuous observation, field rotation every 3 months

G. Micela – Bologna 5/03/2009 Performance of PPLC baseline design magnitude for noise 27 ppm in 1 hr performance of initial industrial design, now being improved highest priority requirement: > 20,000 cool dwarfs with noise < 27 ppm in 1 hr P1 sample P2 sample P5 sample

G. Micela – Bologna 5/03/2009 Performance of PPLC baseline design

G. Micela – Bologna 5/03/2009 Performances telluric planets around stars up to A-type with m V = planets down to 0.6 R earth around G-type stars with m V = with seismic analysis (26,500 stars) planets down to 1 R earth around late-type stars with m V ≤12-13 (>300,000 stars; incl. 60,000 with potential seismic analysis ) transit depth detected at 3  if duration = 10h P1 P5P2

G. Micela – Bologna 5/03/2009 PLATO outcome (1) PLATO will search planets orbiting bright stars. It will therefore possible to follow up the exo-planetary system with ground based and space telescopes (e.g., ELT, JWST, etc. ) to obtain a complete characterization of the planet, its atmosphere, and the whole planetary system PLATO is the only instrument with this capability!

G. Micela – Bologna 5/03/2009 PLATO outcome (2) PLATO will detect Earth-like planets Small size planets orbiting solar-type stars with about 1 year period The exo-planets discovered by PLATO can be fully characterized The same data that PLATO acquires for the planet search, are used to derive the internal structure of the hosting stars (by asteroseismology). This is mandatory to: -Precisely measure properties of exoplanets: mass, radius, age -Comparatively study planetary systems of different age -Correlate the planet and hosting star evolution.

G. Micela – Bologna 5/03/2009 PLATO outcome (3) PLATO will bring us: -complete characterization of large number of exoplanets (size, mass, age,density) - improvement of exoplanet statistics - correlation planetary versus stellar evolution - decisive progress in stellar and planetary evolution modelling PLATO will provide: a complete and unbiased database to understand the evolution of stars and their planets

G. Micela – Bologna 5/03/2009 Date: March 6 * Mission: Kepler Launch Vehicle: United Launch Alliance Delta II Launch Site: Cape Canaveral Air Force Station - Launch Complex 17 - Pad 17-B Launch Time: 10:49:57 p.m. EST Description: The Kepler Mission, a NASA Discovery mission, is specifically designed to survey our region of the Milky Way galaxy to detect and characterize hundreds of Earth-size and smaller planets in or near the habitable zone.KeplerUnited Launch Alliance Delta IICape Canaveral Air Force Station

G. Micela – Bologna 5/03/2009 Time will tell but: 35 hot Jupiters bright enough for RV confirmation (14th mag) - HARPS-N WHT. Superearths? Yes - probably many Terrestrial planets? Probably… Earth analogs?? but difficult to be confirmed through follow up \ Kepler Results (!)

G. Micela – Bologna 5/03/2009 Next steps After characterizing the star-planet systems Substantial progress in theories of planet formation for giant and terrestrial planets Atmospheric properties (giants soon, earths ?) Albedo, clouds, dynamics, temperature, composition Habitability conditions (environment) Biosignatures, identification and observations

G. Micela – Bologna 5/03/2009 Next steps Technical issues The `best’ technology  interferometry or coronography from space Ids of the best target samples: nearby solar type very quiet stars with planet(s) in habitable zone  PLATO could furnish some

G. Micela – Bologna 5/03/2009 Next steps Significant effort of the community to prepare a roadmap for extrasolar planetary science ESA EPR-AT (Exo-Planet Roadmap Advisory Team): will deliver a document next year (spring) – meeting open to the community Jan-Feb 2010 ( BLUE DOTS: Initiative of the community to prepare a roadmap for detection and characterization of habitable exoplanets. Conference in Barcelona (Sept. 2009) (

G. Micela – Bologna 5/03/2009 Just to conclude Extrasolar planet science is growing very quickly A fluorishing of new projects and instruments from ground and from the space with PLATO we will know, on solid statistical bases, which kind of planetary systems exist and their properties PLATO is part of a roadmap that will bring us in some decades (?) to biosignature detection in extrasolar planet atmospheres

G. Micela – Bologna 5/03/2009 Performances 2 « fast » telescopes 40 « normal » telescopes m V = ,000 stars 3 years