PLAnetary Transits and Oscillations of stars

http://www.oact.inaf.it/plato/PPLC/Home.html

- Ultra-high precision photometric space mission

- Candidate M-class mission in ESA Cosmic Vision programme

Main objectives:1. detect and characterize exoplanets of all kinds around stars of all types and all ages

including telluric planets in the habitable zone2. provide full observational basis to study stellar evolution3. enable very wide additional science programme: stellar rotation, stellar activity, binarity,

circumstellar environments, etc.

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: capability of seismic analysis and efficient groundbased follow-up

PLATO Science Objectives

- very large number of targets

- bright and very bright stars

- very long term monitoring

- ultra-high precision photometry

The PLATO challenge

8.0 x 10-5 in 1 hr for marginal transit detection (faint targets)

1 R⊕ planet transiting a solar-like star at 1 AU - mean of 3 transits

Noise level requirements for PLATO

3.4 x 10-5 in 1 hr for high S/N transit measurement: also required for seismic analysis

noise = 2.7 x 10-5 in 1 hr

noise = 4.0 x 10-5 in 1 hr

noise = 6.2 x 10-5 in 1 hr

noise = 8.0 x 10-5 in 1 hr

Noise level requirements for PLATO

3.4 x 10-5 in 1 hr sufficient for seismic analysis

CoRoT observation of a G type star: noise level = 3.4 x 10-5 in 1 hrduration 3.2 months Δν accuracy 1.2 µHz

PLATO target samples> 20,000 bright (~ mV≤11)

cool dwarfs/subgiants (>F5V&IV):

exoplanet transits AND

seismic analysis of their host starsAND

ultra-high precision RV follow-up

noise < 3.4 10-5 in 1hr for 3 years

> 245,000 cool dwarfs/subgiants (~ mV≤13)

exoplanet transits + RV follow-up

>1,000 very bright (mV≤8)

cool dwarfs/subgiantsfor 3 years

>3,000 very bright (mV≤8)

cool dwarfs/subgiantsfor >5 months

exoplanets

around bright and nearby stars

Main focus of PLATO:Bright and nearbystars !!

noise < 8.10-5 in 1hr for 3 years

> 5,000 nearby M-dwarfs (mV≤15)noise < 8. 10-4 in 1hr for 3 years

+ > 5,000 for 2-5 months

+ lists of additionaltargets presentingspecific interest

Instrumental Concept

- 32 « normal » cameras : cadence 25 sec- 2 « fast » cameras : cadence 2.5 sec, 2 colours- pupil 120 mm- dynamical range: 4 ≤ mV ≤ 16

optical field37°

4 CCDs: 45102 18µm « normal » « fast »

focal planes

fully dioptric, 6 lenses + 1 window

Very wide field + large collecting area :multi-instrument approach

optical design

On board data treatment: 1 DPU /2 cameras + 1 ICU Science ground segment

Orbit around L2 Lagrangian point, 6+2 year lifetime

Concept of overlapping line of sight4 groups of 8 cameras with offset lines of sight

offset = 0.35 x field diameter

8 8

8 8

16

16

16 16

2424

2424

32

Optimization of number of stars at given noise levelAND of number of stars at given magnitude

37°

50°

~ 50% of the sky !

0 °

30°

60°

90°

120°

150°

180°

210°

240°

270°

300°

330°

0h2h4h6h8h10h12h14h16h18h20h22h

CoRoT CoRoT

Kepler PLATO

PLATO

1. two long pointings : 3 years or 2 years2. « step&stare » phase (1 or 2 years) : N fields 2-5 months each

Observation strategy and sky coverage

Expected performances

as a function of noise level

as a function of magnitude

88,0009.8 - 11.322,00034

20,000 deg2

118

13.6

11.2

mV

1,30030

25,000

1,300

nb of cool dwarfs& subgiants

KEPLER (100 deg2)PLATO (4300 deg2)

145,0005,000

1,000,000

60,000

nb of cool dwarfs& subgiants

incl. step&stare

1136,00081,300

11.6 - 12.9292,00080

9.3 - 10.815,00027

mVnb of cool dwarfs& subgiants

long monitoring

noise level(ppm/√hr)

20,000

245,000

1,000 3,000

cf presentation by Giampaolo Piottothis afternoon

ESA project team

End-to-end Simulator

W. Zima

PLATO PayloadManagement

PIPM: P. Bodin

PDCPDPM: L. Gizon

Instrument SystemCoordinatorP. Levacher

Science Coordination

H. Rauer

Target/field Characterization

G. Piotto

FU Coordination

S. Udry

Stellar Science M.J. Goupil

Exoplanet scienceD. Pollacco

TOUR. Ragazzoni

Fast DPUG. Peter

Normal DPUPh. Plasson

PLATO Mission Consortium Science PreparationManagement

AlgorithmsR. Samadi

Mission management

AEU S. Fredon

ICUR. Cosentino

Prototype& FM AIVP. Levacher

main / ancillary databasesystem architecture

R. Burston

exoplanet analysis System

N. Walton

data processing implementation

I. Pardowitz

stellar analysis systemT. Appourchaux

Input CatalogueP. Giommi

Data Centre

Normal TOUR. Ragazzoni

Fast TOUW. Benz

Project Manager

Project Scientist Science Team- 6 PMC members- 2 Legacy Scientists

PMC Board

ancillary database content management

M. Deleuil

data analysis support tools

L. Gizon

FPA/FEED. Walton/M. Mas

Hardware & boot softwareM. Mas

Application softwarePh. Plasson

PMC Lead

C. Catala

Camera ManagementD. Laubier

DPS ManagementB. Pontet

Payload

SOC

data processing algorithmsR. Samadi

Additional science W. Weiss

PLAnetary Transits and Oscillations of stars

http://www.oact.inaf.it/plato/PPLC/Home.html

Danke !

Expected noise levelshot noise + readout noise + background noise + jitter + digitization noise

27 ppm

80 ppm

800 ppm

fast cam

8 cam

16 cam24 cam 32 cam

jitter/confusion + background

photon noise

photon noise limited up to mV=11

27 ppm up to mV=10.8

34 ppm

34 ppm up to mV=11.3