SEARCHING FOR PLANETS IN THE HABITABLE ZONE. FROM COROT TO PLATO

1. SEARCHING FOR PLANETS IN THE HABITABLE ZONE. FROM COROT TO PLATO Ennio Poretti – INAF OAB

2. 51 Pegasi : Discovered by Mayor & Queloz (1995, Nature 378, 355) The first extrasolar planet Wolszczan & Frail, 1992, Nature 355, 145

3. RADIAL VELOCITY 635 detections

4. TIMING METHOD: periodic deviations from a given ephemeris. The case of the pulsar PSR1257+12 (10 detections)

5. MICROLENSING (12 detections)

6. ASTROMETRY (waiting for GAIA, used in KEPLER data)

7. DIRECT IMAGING (15 detections) Fomalhaut b : Hubble images taken 2 years apart (Kalas et al.2008)

8. THE TRANSIT METHOD Inclination Orbital distance Planetary radius Using Doppler data too: Planetary mass Density Spectroscopy during the transit: INFRARED: Angle between orbital plane and equatorial plane(Rossiter effect) Ellipticity Photons from planet

10. 0E1 CCD A1 CCD E1 0A1 2.70° 0E2 CCD A2 CCD E2 0A2 3.05° CoRoT Asteroseismology Bright stars 5.5 < V < 9.5 2x5 in each field Exoplanetary search Faint stars 11.0 < V < 16.5 2x6000  in each field Mission life extended to 2012 5 long runs (150 d each or 2x80d) 10 short runs (20 - 30 d) V = 6 --> ~2.5 104 photons cm-2 s –1 outside atmosphere , T ~ 6000°K mv = 16 --> ~2.5 photons cm-2 s -1

11. COROT, 30 cm mirror V> 12 , raw data CoRoT 1b HUBBLE, 2.5m mirror, V=7.8, published curve HD 209458

12. Laurea Thesis Francesco Borsa COROT 1b Mandel & Agol formalism Limb-darkening quadratic law(Claret) RESULTS White light curve a/RS= 4.89±0.06 RP/RS= 0.1334±0.0016 tc= 2593.3263±0.0008 sin i = 0.996±0.001 Coloured light curves RP/RS= 0.1350±0.0018 RP = 1.46±0.07 RG RP/RS= 0.1349±0.0015 RP = 1.45±0.07 RG RP/RS= 0.1332±0.0008 RP = 1.44±0.07 RG Using RS = 1.11±0.05 R

13. CoRoT 3b: the link between stars and planets Laurea Thesis Francesco Borsa P = 4.25695±0.00009d a/RS= 7.90±0.18 RP/RS= 0.0608±0.0006 tc= 2695.5700±0.0012 sin i= 0.998±0.001 RP = 0.78±0.07 RG RS = 1.56±0.09 R RP = 0.78±0.07 RG RP = 0.98±0.06 RG Different depths of the transit Stellar object !! Deuterium burning M = 21.7±1 MJ

14. LINE PROFILE VARIATIONS BY USING HARPS The fingerprint of the nonradial pulsations

15. V1127 Aql: the full Blazhko effect

16. Line profile variations allow us : • To separate radial modes from • nonradial modes • To broke the degeneracy in m • due to the rotational splitting HD 50870 Mean line profile (top) and standard deviation across the line profile (in red after removing 20 frequencies)

17. MODE IDENTIFICATION HD 50844 (l,m couples) Inclination angle: 82°

19. Asteroseismology Power spectrum of light curve gives frequencies n Large separations M/R3 density Small separations d02  probe the core  age Inversions + model fitting + n consistent , M, , J, age: Uncertainty in Mass ~ 2% Uncertainty in Age ~ 10% Asteroseismic age of the Sun: 4.68 +/- 0.02 Gys(Houdek & Gough, 2007) 19

20. N. Batalha et al. [2011 Jan 10]

21. N. Batalha, et al. [2010 Jan 11]

24. Jupiter, Saturn, Uranus, Neptune and icy-rocky trans-neptunian bodies Interaction between giant planets and external bodies. Increase of the angular moments of the giant planets. INSTABILITY: Jupiter and Saturn in 2:1 resonance. Giant planets shifted outward

25. PLATOPLAnetary Transits and Oscillations of StarsThe exoplanetary system explorer Insert footer 25

26. PLATO Science Objectives • Main objective: • detect and characterize exoplanets of all kinds around stars of all • types and all ages  full statistical study of formation and evolution of • exoplanetary systems • including telluric planets in the habitable zone of their host stars • Three complementary techniques: • photometric transits : Rp/Rs (Rs known thanks to Gaia) • groundbased follow-up in radial velocity : Mp/Ms • seismic analysis of host-stars (stellar oscillations) : Rs, Ms, age • > measurement of radius and mass, hence of planet mean density • > measurement of age of host stars, hence of planetary systems • Tool: • ultra-high precision, long, uninterrupted, CCD photometric monitoring of very • large samples of bright stars: CoRoT - Kepler heritage • - bright stars: efficient groundbased follow-up and capability of seismic analysis

27. Instrumental Concept focal planes optical field 37° 4 CCDs: 45102 18m « normal » « fast » On board data treatment: 1 DPU /2 cameras + 1 ICU Science ground segment optical design Very wide field + large collecting area : multi-instrument approach fully dioptric, 6 lenses + 1 window • - 32 « normal » cameras : cadence 25 sec • 2 « fast » cameras : cadence 2.5 sec, 2 colours • pupil 120 mm • - dynamical range: 4 ≤ mV ≤ 16 Orbit around L2 Lagrangian point, 6+2 year lifetime

28. 16 8 8 24 24 16 32 16 24 24 8 8 16 Concept of overlapping line of sight 4 groups of 8 cameras with offset lines of sight offset = 0.35 x field diameter 37° 50° Optimization of number of stars at given noise level AND of number of stars at given magnitude

29. Basic observation strategy very wide field + 2 successive long monitoring phases: Kepler PLATO CoRoT CoRoT PLATO

30. Basic observation strategy • step and stare phase (1 year) : N fields for 3-5 months each • increase sky coverage - potential to re-visit interesting targets • - explore various stellar environments 25% of the whole sky ! Kepler PLATO CoRoT CoRoT PLATO

31. Basic observation strategy • step and stare phase (2 years) : N fields for 3-5 months each • increase sky coverage - potential to re-visit interesting targets • - explore various stellar environments 42% of the whole sky ! Kepler PLATO CoRoT CoRoT PLATO

32. The Discovery Space PLATO Transit RVμlensing 32

33. Planet population predictions Population Synthesis Observations ? Small planets expected to be very common and PLATO could monitor the 42% of the sky ! 33

34. The PLATO challenge monitor in ultra-high precision photometry a very large number of bright and very bright stars

35. THE FUTURE OF ASTEROSEISMOLOGY AND SEARCH OF “EARTHS” Combination of different techniques, from ground and space Spectroscopy Photometry Kepler CoRoT Plato (2018) E-ELT (2017) HARPS, HARPS-N ESPRESSO, CODEX