The PLATO Mission

The PLATO mission La Physique stellaire à l’ère de PLATO Rhita-Maria Ouazzani, Magali Deleuil LIRA, Observatoire de Paris - PSL École Évry Schatzman 2025 Aussois, 22-26 Sept, 2025 PLATO (Planetary Transits and Oscillation of Stars) 2 CoRoT, Kepler, K2, TESS demonstrated the added value of going into space to detect and characterizing stellar systems (host stars and their planets) PLAnetary Transits and Oscillations of stars (PLATO) is a mission specifically devised to simultaneously detect and characterize exoplanets as well as their host stars 2011: failed selection M1/M2 2014: mission selection M3 2017: mission adoption 2018: contract with OHB signed 2019: first CCD delivered 2022: Critical Milestone success 2022: EM tests at SRON and IAS 2024: first FMs integrated in S/C 2025: Mission CDR 2026: launch Ariane 6 2027: start nominal operations 2028: first calibrated data PLATO main objectives for planet science 3 Planets with Mass < 15 M⊕ radius < 10 R⊕ To characterise planets Explore planet diversity Detect and characterize terrestrial planets PLATO main objectives for planet science 4 Planets with precision better than 5% and 10% in radius and mass PLATO To characterise planets Explore planet diversity Detect and characterize terrestrial planets Determine the bulk properties (mass, radius, mean density) of planets for a wide range of systems, including terrestrial planets in the habitable zone of solarlike stars. PLATO main objectives for planet science 5 Planets with precision better than 5% and 10% in radius and mass PLATO To determine the occurrence rate of (super) Earths in the habitable zone of their host star To characterise planets Explore planet diversity Detect and characterize terrestrial planets PLATO main objectives for planet science 6 To determine the occurrence rate of (super) Earths in the habitable zone of their host star Constrain planet formation and evolution processes To characterise planets Explore planet diversity Detect and characterize terrestrial planets ➔Do all potentially habitable planets develop similarly? ➔Which evolutionary paths and stellar environments lead to habitable conditions? PLATO main objectives for planet science 7 To determine the occurrence rate of (super) Earths in the habitable zone of their host star Constrain planet formation and evolution processes To characterise planets Explore planet diversity Detect and characterize terrestrial planets Need to derive not only masses and radii, but also precise and accurate ages for the planetary systems PLATO main objectives for stellar physics 8 To characterise Stars Derive precise and accurate radius, mass and age of planet-hosting stars For a G0V star at magnitude V = 10 ages better than 10% accuracy radii better than 2% accuracy masses better than 15% accuracy To advance our understanding of stellar physics Asteroseismology to constrain stellar evolution models and constrain stellar structure Inferring stellar internal dynamics (in particular rotation and angular momentum redistribution) PLATO main objectives for stellar physics 9 To improve our knowledge of stellar rotation and activity Measuring surface rotation and monitoring photometric activity for tens of thousands of stars Investigating rotation – activity relations will help constrain theories on stellar dynamo Complementary Science Stellar populations and Galactic archaeology Stellar magnetism Classic pulsators Binary stars … PLATO Scientific Programs 16 The PLATO Core Program ●FGK dwarfs and subgiants (F5 to K7) ●Cool dwarfs (M) Designed to fulfill the science objectives of the mission The Science Calibration and Validation stars (scv stars) ●Red giant stars ●γ Doradus stars ●Eclipsing binaries ●Photometrically stable stars Designed to test, improve and validate stellar models → regimes out of reach by the core program → Parameters derived using model-independent methods Complementary Science Program ●Binary and multiple stars ●Pulsating stars (earlier than F5) ●Magnetic stars and rotational variables ●Stars with mass loss ●young stellar objects and stars with debris disks ●Galactic structure ●Transient phenomena and extragalactic science Designed to serve the wider community with photometric obso PLATO Scientific Programs 17 P1 sample FGK dwarfs and subgiants Vmag<11 P2 sample FGK dwarfs and subgiants Vmag<8.5 P4 sample M dwarfs Vmag<16 P5 sample FGK dwarfs and subgiants Vmag < 13 From ESA-PLATO-ESTEC-SCI-RS-001 PLATO Data products 18 corrected & calibrated data science products follow-up data final catalog raw data PLATO Data products 19 corrected & calibrated data follow-up data final catalog raw data stellar science products PLATO Data products 20 corrected & calibrated data follow-up data final catalog raw data stellar science products +Additional data products: • Analyses-ready cleaned light curves • Additional seismic parameters: splittings, heights, inclination angles, mean density • Additional stellar parameters: effective temperature, metallicity, abundances, … From PLATO photometry to Stellar properties 21 © MPS/MarkGarlick.com Example CoRoT target HD52265 (Ballot et al. 2011, Ballot & Garcia 2019) Fourier Transform 22 © MPS/MarkGarlick.com From PLATO photometry to Stellar properties Rotation 23 © MPS/MarkGarlick.com From PLATO photometry to Stellar properties Rotation Activity 24 © MPS/MarkGarlick.com From PLATO photometry to Stellar properties Rotation Activity Credit: NSO/NSF/AURA Granulation 25 © MPS/MarkGarlick.com From PLATO photometry to Stellar properties Rotation Activity Credit: NSO/NSF/AURA Granulation Oscillations From Goupil et al. (2024) M R Teff Expected yield after 2 years for P5 sample ●Oscillations detected in 7% of P5: 9491 mostly subgiant stars ●Detection rate of MS stars positive after a year Yield: asteroseismic detection (MSAP3) P5 sample PLATO Science Requirements Mass better than 15%, Radius better than 2%, Age as low as 10% reference star 1Msun , 1Rsun and Teff = 6000K. Yield: MRA inference (MSAP5) P1-P2 samples seismic inferences based on measurements of individual modes. → δM/M, δR/R and δA/A are directly related to δ𝜈 PLATO Science Requirements Mass better than 15%, Radius better than 2%, Age as low as 10% reference star 1Msun , 1Rsun and Teff = 6000K. Yield: MRA inference (MSAP5) P1-P2 samples seismic inferences based on measurements of individual modes. → δM/M, δR/R and δA/A are directly related to δ𝜈 2-year baseline, P1-P2, MS, M< 1.2 Msun PLATO Science Requirements Mass better than 15%, Radius better than 2%, Age as low as 10% reference star 1Msun , 1Rsun and Teff = 6000K. Yield: MRA inference (MSAP5) P1-P2 samples Asteroseismic yield compared with Kepler % 67 stars in the Kepler legacy sample Creevey et al. (2017) From Goupil et al. (2024) More about seismology with PLATO: See practical session by S. Deheuvels and J. Ballot this afternoon From Breton et al. (2024) ●Simulated light curves for P1-P2 samples (based on PIC 1) ●Estimated recovery rate for rotation and cycle periods Yield: rotation measurement (MSAP4) P1-P2 From Breton et al. (2024) ●Simulated light curves for P1-P2 samples (based on PIC 1) ●Estimated recovery rate for rotation and cycle periods Yield: rotation measurement (MSAP4) P1-P2 From Breton et al. (2024) ●Simulated light curves for P1-P2 samples (based on PIC 1) ●Estimated recovery rate for rotation and cycle periods Rotation recovery ●Criterium: δProt/Prot < 10% ●Very good recovery rate after 1 or 2 years ●Smaller spread for shorter periods and longer baseline Yield: rotation measurement (MSAP4) P1-P2 See lecture by S. Breton and G. Bruno tomorrow Beyond SAS: the challenges PLATO will allow us to tackle 40 Probe convective/radiative interfaces Complex regions Very turbulent → non-linear processes variety of time and space scales 3D by essence Mao et al. (2024) Anders et al. (2023) Impacts stellar structure and evolution Mixes of chemical elements Shapes angular momentum distribution Modifies thermal stratification Beyond SAS: the challenges PLATO will allow us to tackle 41 Probe convective/radiative interfaces Interfaces subject to convective penetration or overshoot Included in stellar models through extra mixed layer or a diffusion coefficient in transport equations → overshoot parameter 𝛼ov Anders et al. (2023) Conclusions 48 Characterising stars better than ever before After CoRoT and Kepler, PLATO will constitute a leap forward in characterisation of stellar masses, radii and ages, thanks to synergies with Gaia and ground-based spectroscopy Number of stars with accurate and precise global parameters and internal structure will increase by two orders of magnitude Towards a new generation of stellar models Unprecedented insight into stellar interiors access to … … dynamical properties of stellar interiors … constraints on convective/radiative interface mixing … insight into stellar magnetism and dynamo processes