the origin of the mission the scientific requirements the global programme

Annie Baglin, Natal, October 30th 2004

1

The origin of the missionThe scientific requirements

The global programmeThe focal plane and the targets

The scientific organisation

COnvection, ROtation and planetary TransitsCOnvection, ROtation and planetary Transits

An introduction to the CoRoT mission

http://www.astrsp-mrs.fr/projets/corothttp://cnes.mission.fr/corot


2

The COROT concept

* Ultra high precision stellar variability* Very long duration of observations * without interruption* on a large variety of starsRelative variations of stellar quantitiesmainly in the optical domain,Analysis in the time/frequency space

Photometry from Space Ministallite World wide pioneerWorld wide pioneer


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The early days of the space adventure

First Colloquium Observatoire de Paris in 1984

Workshop on Improvements to photometry San Diego 1984

Stating the importance of space for stellar seismology and activity

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0 1 2 3 4 5 6

rel power /10**4 μHz

mHz

scintillation

transparency

+ scintillation transparency

from E. Fossat, San Diego Workshop,

• High resolution Spectroscopy Large telescopes Limited to low Vr

• Photometrylimited by scintillation on the ground

Goal: < ppm in 5 days : ~ 2 10-7 / μHz~ 1000 times less !

2 10-4 / μHz


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EVRIS

Telescope 15 cm, Built in Meudon, Marseille and Austria

On board the Soviet spacecraft Mars 96

Observation of 10 very bright stars During the cruise to Mars

MOST (μ sat Canada), analogous to EVRIS is now flying…..

CRASH!But…….

After many proposals on different programmesEVRIS accepted by CNES…… in 89


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Several european projects

Combining seismology and activity (visible and UV instruments)

PRISMA(1993)

1m visible, 3° FoVFar UV 10cm monitor CII

Large phot (40,1.5°)Small phot (15 cm, 3°)

UVSpectro (57cm, R=30 000)XUV tel (40cm, 13nm)

STARS (1996)

But not selected


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The long way to go….

But……. crash of Mars 96, ……..discovery of exoplanets in 95 ……..improvement of detectors

…..New proposal in 97

Started in 93 as an answer to a AO for minisats by CNES

As a second generation mission……

Preselected in 98Selected in 2000 launch in 2004..!Confirmed in 2002 after some threat…..European

and Brasilian partners


7

Seismology requirements/1

The solar template(only star observed in photometry)

2 ppm

5 days

Amplitude behavior fromspectroscopic stellar seismology

av ~ (L/M)0.7

Parameters of a stellar mode ?

Amplitudes in Vr relative to the Sun (27cm/s)From Samadi et al (2004)

HD 49933


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Seismology requirements/2

a= 2 ppm, T = 5 days, ---->>N ≥ 5 106 ph/s

N mean counting rate (ph/s), a amplitude variance of a white noise t = inf (T, ) T total duration of the observation, life-time of the mode

S/N = N2 a 2 t/ 4 in the power spectrum

If Photon noise limited S/N = N a 2 t / 4

log(D/25cm) ≥ 0.2 (mv - 6)

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16

-1 -0.5 0 0.5 1 1.5 2 2.5 3log D

2ppm , 5d

10ppm , 5d

10ppm , 40d

* A periodic signal in a white noise

* Frequency resolution: << 2 μHz 0.1 μHz T > 120 days

* No window alias: duty cycle > 90%

Detection probability 99 % : S/N ≥ 9

mv=6D=27cm


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Detection of small planets

* Brightness variation during a transitF/F= (Rpl/Ret)2

Earth : 10-4 , Jupiter : 10-2

F/F

t(hrs)100 ppm

≈10 hrs

Telluric planets are detectableTelluric planets are detectableif photon noise < 10if photon noise < 10-4-4 in a few h in a few h

* Duration of a transit * Duration of a transit = P 2R= P 2R**/2/2 a a a1/2 R R**

Earth: 14h, Jupiter 31h, 51 Peg 3h

* Periodicity* PeriodicityDuring a run T >> PNumber of observed transits : N = T/P a-3/2 Cumulated signal : N a-1

Favors planets close to the starFavors planets close to the star

•Low probability to be in the orbital plane: observe a large number of targets

In photometry, through transits..


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Exoplanet programme requirements

* Seismology specifications compatible with transit detection of earth-like planets

D ≥ 25 cmNphot= 10-4 in 3 hours for mv=14

T ≥ 120 days3 transits for a < 0.3 u.a.

* ~ 12 000 * mv < 16

FOV ~ 4 sq deg--> specific regions of the sky

* Confusion transit/activity chromatic device can separate ……

Three colors aperture photometryon dispersed images

Exoplanet Field

On focus(prism)


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β

Mission profile

1 Long run ~150 days 1 Short run ~(180-150-10) each half year(duration can be modulated)A few short runs at the beginning

Mission profile

Beginning of observation zone 1

Sun

Earth orbit

Beginning of observation zone 2

180 ° Rotation of SC

Corot Orbital plane

Constraint of Low Earth Orbit / Requirement Run duration ≥ 120 days

Limited regions of the sky accessibleWide set of stars --> mv ~ 6

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-10

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-150 -100 -50 0 50 100 150

Exemple de zônes d'observation possibles

Altitude 900 Km, Gom=0

delta

alpha

A B


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The focal plane

12000 targetssampling 512 s

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*

**

*

*

* *

*

*

•

•

•

•

•

1.3 °

field of view

Seismology field highly out of focus

main target (≤ 6)

secondary targets (≤ 9.5)

10 targetssampling 1 s

Exoplanet fieldOn focus + bi-prism

faint stars (11-16)

Short duration mission (2.5 y) -->Simultaneity of the two programmes


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Photometric performances in the seismology field

For mv=5.7 in five days photon noise Np = 0.6ppm total noise Nt = 0.61ppm

Nt= 0.61 10 0.2(mv-5.7) for mv<9

For mv > 9 increase of the readout noiseVery low jitter and background noises

Aperture photometry on highly out of focus images50 pixels (1px = 2.32 arcsec)

Photon noise and total white noise as a function of magnitude

in ppm for a five days observation

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2

4

6

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5 6 7 8 9 10 11

White noise on 5 days

Photons noise (ppm on 5 days)

mv

Red: total noiseBlue: photons noise


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Photometric performances in the exoplanet field

Exoplanet Field

On focus(prism)

The jitter is the major source of instrumental noise

It will be corrected on ground, See Fabio’s talk

Blue (resp. red) :30±8 (resp. 40 ±15) % of the total flux do not correspond to a fixed photometric system

0

0,0002

0,0004

0,0006

0,0008

0,001

0,0012

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Noise for 1h integration

photon noise PF 1h

mv


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The planet hunting Race

0.01

0.1

1

10

100

1000

104

0.01 0.1 1 10 100

m (Terre) a (au)

KEPLER(2008/9)KEPLER(2008/9)EDDINGTON(?)EDDINGTON(?)HabitableHabitable

zonezone

Vr (2003)Vr (2003)

COROT (2006)COROT (2006)

GAIA (2011/2)GAIA (2011/2)


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High precision photometric data

Secondary science with CoRoT ?Described e.g. in Weiss et al 2004 Palermo Eddington colloquium

Wide variety of subjects and interest

*Large and complete stellar data base of more than 100000 stars11 < V < 16

*Also a few selected targets

Creation of the Additional Programmes


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Browsing in the exoplanet data

Measuring limb darkening with binaries

Defining the Dor domain

COROT

Detecting infalling comets


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Observing specific objects

EX: NGC 2264

from WEBDA

• v<8.5• 8.5<v<9.5• 9.5<v<12+ v>12

Up to 10 stars inCCDA1 and CCDA2Or many faint ones in exo field

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8.5

9

9.5

10

10.5

11

9999.5100100.5101


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The global programme

Core programmeSeismology +Exoplanet(In the corresponding focal planes)

Central programme ≥ 5 long runs (150 days)

50 S targets mv < 9.5 60 000 E targets mv < 15.5

Exploratory programme ~ 4 short runs (10 to 20 days)

50 S targets mv < 9.5 60 000 E targets mv < 15.5

Restricted to Co-Is and their teams

Additional programmes Any scientific field

except Core Programme

• ~ 4 specific short runs50 S targets mv < 10.5 ? 60 000 E targets mv < 16 ?

• A few targets in the exoplanet field

• Use of the data of the core programme

Open AO, GIs


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The eyes of COROT

C1: density dwarfs ≥ 1500 per square degree

at mv<15.5

C2: ≥ 5 main targets FGK IV, V mv< 6.5 Delta scuti < 9

Scientific Constraints

=102.5 and 282.5

Early feasibility studies based on catalogues and plates


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Ground based complementary observations

Effort supported by Laboratories and Participating Countries

Collection of data on potential targets to determine the fundamental parameters (Teff, logg, [Fe/H], Vsini..)select the targetsprepare ground-based support and follow-up

Bright for the seismology field > 250 nights > 250 nights 0.9 to 3.5 m telescopes0.9 to 3.5 m telescopes > 1500 stars> 1500 starsData base: GAUDI at LAEFF

Faint stars for the exoplanet field ≥ 2.5m telescopes 100 million starsData base: EXODAT at LAM


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Seismology GBO

1-Photometric & spectroscopic observations of targets up to mV=8 for scenarii 1.2.3.4

• All observations complete: about 1500 stars .Data in GAUDI• Teff, log g, MV, [Fe/H], vsini, VR derived from these data, in Corotsky and GAUDI

Stromgren photometry from OSN, SpainHigh res. spectroscopy from ELODIE/OHP

FEROS (ESO+BRASIL) SARG/TNG +Coralie + Tautenburg

2- New targets to be observed because of possible drift of orbital plane(552 new targets, 68 near primary objects)

• Work started on ESO/FEROS (Renan)

3- Observations of targets with 8 ≤ mV ≤ 9.5 in 1.4° x 2.8° field around main targets

(386 stars)photometric Stromgren observations: IAA/OSN in 2004/2005spectroscopic observations:proposal for CFHT/Espadons for 2005A (all 386 stars in 3 nights)additional proposal for ESO/FEROS


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Preselected fields for long runs

-10-50510

-10

-5

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5

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171834

177552

181555

170580

18064243587

49434

49933

522651Winter 2006/7

2Summer 2007


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Seismology targets

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3.63.73.83.944.1

43318

43587

45067

49434

49933

46558

52265

171834

177552

175726

181555

171234

180642

log teff

2.4Mo

2.0Mo

1.8Mo

1.4Mo

1.0Mo

170580 ?

Principal targets A possible choice for secondary targets

Need of more precise fundamental parameters


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A possible HD 49933/49434 long run

Exobasket

Rrange contam E1 E2 Total

11-15 0.1 2630 2221 4851

11-15 0.2 425 265 690

15-16 0.1 1845 1200 3045

15-16 0.2 601 926 1527

11-16 0.2 5501 4612 10113

11-14 > 0.2 181 173 354


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Next steps

1- CW7 in Granada December 2004- confirm the two first fields for the long runs: LR1a, LR1c

star densities for exo, set of secondary targets for sismo

2- January 2005 AO for AP CoRoT year 1

3- CW8 in Toulouse June 2005- prepare the first short runs SR0a (split in 2? Also technical), SR1a- define the next two other long runs: LR2a, LR2c- select the AP for CoRoT year 1

4- CW9 December 2005- Selection of the first short runs SR0a, SR1a, SR1c: AP?- define the next two other long runs: LR3a, LR3c

5- January 2006 AO for AP CoRoT year 2……….

Still preliminary…….subject to modifications


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The COROT Team

• RSSD/ESTEC: MDP Unit

• SPAIN: Ground segment

• AUSTRIA: participation to the DPU

• ESA Scientific programme: Optics and AIT contribution

• BELGIUM: Baffle, cover, mechanics of the service module

• GERMANY: onboard software

• BRAZIL : antenna, ground segment software

• Contributions : Italy, Romania, Hungary.. (ground + science)…...

• FRANCE : 3 space laboratories : • LAM Marseille,

• LESIA Observatoire de Paris,

• IAS Orsay • Contributions of GEPI, OMP, IAP, OCA, OHP

CNES : global responsability of the mission


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The Scientific Organisation

Seismology W.G.

E. Michel

Scientific Committee

Additional Prog.W.G.

W. Weiss

CORE programme Central + Exploratory

Exoplanet W.G.

P. Barge

SeismologyGround based obs.

C. Catala

Sc. TeamsCo_Is

Sc. TeamsCo_Is

Sc. TeamsCo_Is

Sc. TeamsCo_Is/GIs

Sc. TeamsCo_Is

Exoplanet Complement obs.

M. Deleuil


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The Scientific Committee

• Chairperson : PI • CNES Programmes Directorate • Project Scientist • Representatives

major laboratory (6)

participating countries(• Chairs of the Working Groups (5) • Project Manager (invited)

In charge of

- the scientific specifications - the programme of observations - the data distribution policy - the list of Co-Is and Gis - Programme of CWs - Public relations

COROT WEEKS twice a year

Open scientific Meetings + CS and WGs

7th in Granada (Spain), Dec 14th to 17th

Meetings:Twice a year or more At each CW

Nice 1999

Marseille 2003


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The data policy

Public release

Observation

Data reduction

Distribution of I(t)to the CoIs and GIs

150 days

~ a few months

~ 1 yearResponsability: Project Team

*

Publications will be put on a secured siteTo be Referred by the SC within 15 days (TBC)


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Do sonho ate a realidade

~ Junho 2006…..!


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MOST a pionner microsat

1st canadian microsatelliteLaunched June 30th 2003Suitcase size15 cm collectorMono-objectHeliosynchroneus LEO

A few bright stars , 30 days mv = [ 0,5] of all types

Procyon, amplitude spectrum a) observed by MOST for 32 days

b) simulated signal: p modes 10ppm and 3 days lifetime


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KEPLER

Terrestrial planets findingNASALaunch 2008?

95 cm Schmidt telescopeFOV 100deg2 100 CCDs Trailing orbit

5 years on one field


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EDDINGTON: the mission

4 identical co-aligned60 cm Schmidt telescopesOn a Herschel busFOV = 35 deg2

At L2

Programmatic difficulties….???

Culmination of the European effortsHorizon 2000 + medium size mission

Seismology + Planet finding


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GAIA

ESA Cornerstone 2010-2012

Stellar physics

Fundamental parametersLuminosity calibrationVariability levelsBinaries……

Planet finding

Astrometry>10 000 P ~yrs

Photometry> 5000 P ~days

0

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0.8

1

1.2

cosδ (")

1/01/00

1/01/01

1/01/0

1/01/03

1/07/00

1/07/01

1/07/0

δ(")

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cos δ (")

1/01/00

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1/07/0δ(")

0 0. 0.4 0.6 0.8 1.0

: Planète ρ = 100 = 18 mas P mois

HR diagramHyades

HIPPARCOS

Age 625±50 MyrY=0.26±0.02


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DARWIN/TPF

2015 ?

Imaging the planetsInterferometry or coronography

the origin of the mission the scientific requirements the global programme

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