Transcript http://www.lesia.obspm.fr/cosmicvision/plato beyond CoRoT & Kepler  PLATO PLAnetary Transits & Oscillations of stars Next generation mission for ultra-high precision stellar photometry Search for and characterisation of.

http://www.lesia.obspm.fr/cosmicvision/plato
beyond CoRoT & Kepler

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
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)
transit detection
- Porb, Rp/R*, R*/a
seismic analysis
- R*, M*, age
- interior
spectro, RV, G/B photometry, imaging,…
- exoplanet confirmation
- Mp/M*2/3
- chemical composition of host stars
- … and of exoplanet atmospheres
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
(~ mV≤11)
cool dwarfs
(>F5V); noise < 27 ppm in 1hr
= 1 ppm in 30 d
= req. seismic analysis
- P2: > 80,000 bright cool dwarfs; noise < 80 ppm in 1hr during long pointing
but < 27 ppm in 1 hr during step & stare phase
= req. for 1Rearth
- 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%
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
The PLATO study organization
ESA
study scientist, study manager, payload manager
M. Fridlund
R. Lindberg
D. Lumb
2 industrial
contractors
ESA
PSST
PLATO Consortium Council
Payload + SVM
PPLC =
PLATO Payload Consortium
PI: C. Catala
Co-Pi: M. Deleuil
study of payload
system
telescopes/optics
FPA
onboard data processing
ground data centre
PSC =
PLATO Science Consortium
PI: D. Pollacco
Co-Pis: G. Piotto
H. Rauer
S. Udry
science case
scientific preparation
field characterisation and choice
follow-up observations
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
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
Performance of PPLC baseline design
Performances
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
planets down to 1 Rearth
around late-type stars with mV≤12-13
(>300,000 stars; incl. 60,000 with
potential seismic analysis )
telluric planets
around stars up to A-type with mV=9.6-11.1
Performances
2 « fast » telescopes
40 « normal » telescopes
mV = 10.5
30,000 stars
3 years
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