From stars to habitable Planets

1
An introduction to the CoRoT mission
The origin of the mission The scientific
requirements The global programme The focal plane
and the targets The scientific organisation
COnvection, ROtation and planetary Transits
http//www.astrsp-mrs.fr/projets/corot http//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 stars
• Relative variations of stellar quantities
• mainly in the optical domain,
• Analysis in the time/frequency space
• Photometry from Space
• Ministallite
• World wide pioneer

3
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

• High resolution Spectroscopy
• Large telescopes
• Limited to low Vr
• Photometry
• limited by scintillation on the ground

2 10-4 / mHz
Goal lt ppm in 5 days 2 10-7 / mHz 1000
times less !
from E. Fossat, San Diego Workshop,
4
EVRIS
After many proposals on different
programmes EVRIS accepted by CNES in 89
On board the Soviet spacecraft Mars 96
Telescope 15 cm, Built in Meudon, Marseille
and Austria
Observation of 10 very bright stars During the
cruise to Mars
CRASH!
But.
MOST (m sat Canada), analogous to EVRIS is now
flying..
5
Several european projects
Combining seismology and activity (visible and UV
instruments)
PRISMA(1993)
Large phot (40,1.5) Small phot (15 cm,
3) UVSpectro (57cm, R30 000) XUV tel (40cm,
13nm)
STARS (1996)
1m visible, 3 FoV Far UV 10cm monitor CII
But not selected
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The long way to go.
Started in 93 as an answer to a AO for minisats
by CNES As a second generation mission
But. crash of Mars 96, ..discovery of
exoplanets in 95 ..improvement of
detectors ..New proposal in 97
Preselected in 98 Selected in 2000 launch in
2004..! Confirmed in 2002 after some threat..
European and Brasilian partners
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Seismology requirements/1
Parameters of a stellar mode ?
Amplitude behavior from spectroscopic stellar
seismology
The solar template (only star observed in
photometry)
av (L/M)0.7
2 ppm
HD 49933
5 days
Amplitudes in Vr relative to the Sun
(27cm/s) From Samadi et al (2004)
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Seismology requirements/2
A periodic signal in a white noise
S/N N2 a 2 t/ 4 s2 in the power spectrum

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

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

Detection probability 99 S/N 9
a 2 ppm, T 5 days, ----gtgtN 5 106 ph/s
log(D/25cm) 0.2 (mv - 6)

• Frequency resolution ltlt 2 mHz 0.1 mHz T gt
  120 days
• No window alias duty cycle gt 90

mv6 D27cm
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Detection of small planets
In photometry, through transits..
Brightness variation during a transit DF/F
(Rpl/Ret)2 Earth 10-4 , Jupiter 10-2

• Duration of a transit t
• t P 2R/2p?a ? a1/2 R
• Earth 14h, Jupiter 31h, 51 Peg 3h

Telluric planets are detectable if photon noise lt
10-4 in a few h
Periodicity During a run T gtgt P Number of
observed transits N T/P ? a-3/2 Cumulated
signal N t ? a-1 Favors planets close to the
star

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

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Exoplanet programme requirements
Seismology specifications compatible with
transit detection of earth-like planets D 25
cm Nphot 10-4 in 3 hours for mv14 T 120
days 3 transits for a lt 0.3 u.a.
12 000 mv lt 16 FOV 4 sq deg --gt
specific regions of the sky
Three colors aperture photometry on dispersed
images
Confusion transit/activity chromatic
device can separate
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Mission profile
Mission profile
Constraint of Low Earth Orbit / Requirement Run
duration 120 days
Limited regions of the sky accessible Wide set of
stars --gt mv 6
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The focal plane
Short duration mission (2.5 y) --gtSimultaneity
of the two programmes
12000 targets sampling 512 s
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Photometric performances in the seismology field
Aperture photometry on highly out of focus
images 50 pixels (1px 2.32 arcsec)
For mv5.7 in five days photon noise Np
0.6ppm total noise Nt 0.61ppm Nt 0.61
10 0.2(mv-5.7) for mvlt9 For mv gt 9 increase
of the readout noise Very low jitter and
background noises
Photon noise and total white noise as a function
of magnitude in ppm for a five days observation
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Photometric performances in the exoplanet field
Blue (resp. red) 308 (resp. 40 15) of the
total flux do not correspond to a fixed
photometric system
The jitter is the major source of instrumental
noise It will be corrected on ground, See
Fabios talk
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The planet hunting Race
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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 stars 11 lt V lt 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 g Dor domain
Detecting infalling comets
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Observing specific objects
EX NGC 2264
vlt8.5  8.5ltvlt9.5 9.5ltvlt12 vgt12
from WEBDA
Up to 10 stars in CCDA1 and CCDA2 Or many faint
ones in exo field
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The global programme
Core programme Seismology Exoplanet (In the
corresponding focal planes) Central programme
5 long runs (150 days) 50 S targets mv lt
9.5 60 000 E targets mv lt 15.5 Exploratory
programme 4 short runs (10 to 20 days)
50 S targets mv lt 9.5 60 000 E targets
mv lt 15.5 Restricted to Co-Is and their teams

• Additional programmes
• Any scientific field
• except Core Programme
• 4 specific short runs
• 50 S targets mv lt 10.5 ?
• 60 000 E targets mv lt 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
Early feasibility studies based on catalogues
and plates
a 102.5 and 282.5
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Ground based complementary observations
Collection of data on potential targets to
determine the fundamental parameters (Teff,
logg, Fe/H, Vsini..) select the
targets prepare ground-based support and
follow-up
Bright for the seismology field gt 250 nights
0.9 to 3.5 m telescopes gt 1500
stars Data base GAUDI at LAEFF
Faint stars for the exoplanet field 2.5m
telescopes 100 million stars Data base
EXODAT at LAM
Effort supported by Laboratories and
Participating Countries
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Seismology GBO
1-Photometric spectroscopic observations of
targets up to mV8 for scenarii 1.2.3.4
Stromgren photometry from OSN, Spain High res.
spectroscopy from ELODIE/OHP FEROS
(ESOBRASIL) SARG/TNG Coralie Tautenburg

• 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

• 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
  2004/2005
• spectroscopic 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
2 Summer 2007
1 Winter 2006/7
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Seismology targets
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
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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
CNES global responsability of the mission

• FRANCE 3 space laboratories
• LAM Marseille,
• LESIA Observatoire de Paris,
• IAS Orsay
• Contributions of GEPI, OMP, IAP, OCA, OHP

• 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)...

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The Scientific Organisation
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The Scientific Committee
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

• Chairperson PI
• CNES Programmes Directorate
• Project Scientist
• Representatives
• major laboratory (6)
• participating countries(
• Chairs of the Working Groups (5)
• Project Manager (invited)

Marseille 2003
Nice 1999
7th in Granada (Spain), Dec 14th to 17th
You are all welcome!
MeetingsTwice a year or more At each CW
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The data policy
Publications will be put on a secured site To 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 microsatellite Launched June 30th
2003 Suitcase size 15 cm collector Mono-object Hel
iosynchroneus 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 finding NASA Launch 2008?
5 years on one field
95 cm Schmidt telescope FOV 100deg2 100 CCDs
Trailing orbit
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EDDINGTON the mission
Culmination of the European efforts Horizon 2000
medium size mission Seismology Planet finding
4 identical co-aligned 60 cm Schmidt
telescopes On a Herschel bus FOV 35 deg2 At
L2 Programmatic difficulties.???
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GAIA
ESA Cornerstone 2010-2012

• Planet finding
• Astrometry
• gt10 000 P yrs
• Photometry
• gt 5000 P days

Stellar physics Fundamental parameters Luminosity
calibration Variability levels Binaries
HR diagram Hyades HIPPARCOS Age 62550
Myr Y0.260.02
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DARWIN/TPF
Imaging the planets Interferometry or
coronography
2015 ?