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CoRoT HighlightsCoRoT Highlights
Annie Baglin and Eric Michel Annie Baglin and Eric Michel
Observatoire de Paris Observatoire de Paris
and all the CoRoT Teamand all the CoRoT Team
* The Mission* The Mission
* Seismology* Seismology
* Stellar Rotation and Activity* Stellar Rotation and Activity
* Exoplanets* Exoplanets
Time Domain Time Domain StellarAstrophysicsStellarAstrophysics
2 major Scientific
Programmes
Same technical specifications
* Very high accuracy (1000 times better)
* Very long duration of observation of the same star ~150 days
* Very high duty cycle (> 90 %)
A « SMALL » space mission built and operated by CNES (France) with ESA, Austria, Belgium, Brazil, Germany and Spain
STSci Colloquium, Octpber 6th 2010
What is CoRoT ?
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Detect stellar oscillations like in the Sun to probe the stellar interior
Detect small planets through their transit
Stellar ultra high precision relative photometryStellar ultra high precision relative photometry
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The CoRoT Instrument The CoRoT Instrument
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Up to12 000 Faint stars R : 10 to 16
At 32 or 512 s
Telescope diameter 27cm Camera with 4 detectors
10 bright stars
V : 5.5 to 9.5 at 32s
March 8 2009
116 bright stars (+ 20 to 30)120 000 faint ones (+35 000)
STSci Colloquium, October 6th 2010
Launch December 27th 2006, 1378 days in orbitFunded till march 2013
Total cost= 160 M€
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The CoRoT product: light curvesThe CoRoT product: light curves
STSci Colloquium, October 6th 2010
Time Domain Stellar Astrophysics
New field of research since ~ 2000
High precision, long duration, continuity- MOST and WIRE from space
- Ground based networks coordinated in longitude-- CoRoT, Kepler
-- ……
116 up to now + use of the exofield targets
The seismology targets
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9 Delta Scuti, 2 known gam Dor
16 B stars, 1Beta Ceph, 5 Be
12 giants (K,G,F)
22 A/early F stars ?2 Am, 7 Ap,
17 solar-like puls. cand.
(one observed twice)
7 O stars
1 SdB Few RR Lyr
STSci Colloquium, October 6th 2010
Analysis of the light curves in the Fourier space
Rotation (days)
Oscillations (mn to h)
Granulation, super granulation…
Magnetic activity
STSci Colloquium, October 6th 2010
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V= 7 V = 8
V= 6
White noise
granulation oscillationsAround 1 to 3 mHz
Almost regular spacing(as predicted)
Large separation Small separation
Detection of solar like oscillationsin Solar analogs
Michel et al. Science 2008Benomar et al. A&A 506, 2009
STSci Colloquium, October 6th 2010
Difficulty: identification of the modes Spherical harmonics (n, l, m)Through a fit to an empirical spectrum
Echelle diagram
First interpretations
STSci Colloquium, October 6th 2010
HD 49933 M= 1.13, Fe/H=-0.37, Prot=3.35 dCore ~8%, ZC 88%, 3 Gyr
dark = 0.2, Dturb = 50cm2/sMedium =0.2 Dturb =0light =0.1, Dturb =0
=0.0, Dturb =0
(Goupil et al 2010 A&A accepted)
Oscillations in the frequencies due to sharp features in the structure
(Mazumdar and Michel 2010, AN in press)
Extension of the core and mixing ?
Basis of the outer ZC and Helium ionisation zone
Seen also in a red giant !
HD 43587, F9V
HD 52265metal rich G0V star
Hosting a planetBallot et al. A&A submitted
In Cooler solar analogs
HD 46375, K0V, hosting a 3days planet ~135 Hz (Gaulme et al, A&A accepted)
STSci Colloquium, October 6th 2010
Off the MS
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Blue l=0Red l=1
Green l=2Violet l=3
HD 49385HD 49933
Large amplitudesBrighter than the Sun
Vconv higherSame T
Life time of the modes longer
X
49385
X49933
Deheuvels et al. A&A accepted
STSci Colloquium, October 6th 2010
a mixed mode
In Post MS only
What a mixed mode can tell ?
STSci Colloquium, October 6th 2010
Hz
acobs = 748.6 ± 0.23 Hz
Models fitted to Teff, L/Lo, Z/X,
And
1.3 < M < 1.36 Mo
•The curvature of the ridge modified by the avoided crossing
* The frequency of the mixed mode (g type)
overshootingov < 0.15
But..presently unsuccessfulseveral modes involved
Some physics missing ?
Solar like oscillations in a Red Giant
Detection of the comb structure
l=0,1,2
= 3.47 Hz
= 0.65 ??
Mode lifetime14.7 days
Teff= 4750 K, L= 70 LoVery slow rotator
At very low frequency: ~ 30Hz
156 days
Carrier et al. A&A, 506 2009
STSci Colloquium, October 6th 2010
A universal spectrum
STSci Colloquium, October 6th 2010
Mosser et al. A&A accepted
De Ridder et al. Nature 2009
max
n,l / = n + l/2 +d 0,l
CoRoT
Kepler
Scaling law for ?
= A + B log
A Stellar Formation Rate indicator
* Statistics on max and Compared to models of synthetic populations
Miglio et al. A&A 2010
STSci Colloquium, October 6th 2010
T1: constant formation rateT2: recent burst ≤ 1 Gyr
* Determination of Mass and Radius ( max )
Hot stars and solar like oscillations….
AAS Miami May 2010
Gravity modes?
Auto excitedBeta ceph
Solar like P modes
Deep interior, He ionisation zone, convective region
Belkacem et al. , Science, 2009
HD 461490 8.5 V
Teff= 35 000
NGC 2244Rosetta nebula
1,6 Myr
Red 30 MoGreen 34 Mo
Degroote et al.A&A accepted
HD 180642 B1 VTeff ~ 26 000 Log g= 3.8
STSci Colloquium, October 6th 2010
Excitation mechanism?
The instability strip close to the MSDelta Scuti stars
130 stars with good fundamental parameters
80 % amplitudes [10-2 ,10-4]
Extremely rich spectrum
Many modes predicted unstable
Statistics ?
How to disentangle pulsations and granulation?
But……Rotation generally dominates….!
Beta Cephei pulsators
Briquet et al. A&A 2010 accepted
67 Frequencies
STSci Colloquium, October 6th 2010
NO pusations detected, Only rotation (Papics et al. A&A submitted)
The Beta Cephei instability strip ?
STSci Colloquium, October 6th 2010
HD 180642
67
NO
A Be star with a burst
HD 49330 V= 8.5 during 156 days
Enveloppe / pulsation Interaction ?
Huat et al. A&A 506,2009, Floquet et al. A&A 2010
STSci Colloquium, October 6th 2010
An old hot B subdwarfVery faint, (V=14.9)
observed in the exoplanet field
24 frequencies (6 from the ground)g modes
Charpinet et al. A&A L, submitted
STSci Colloquium, October 6th 2010
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The Rotation of the Sun in timeThe Rotation of the Sun in time
Extended program of spectroscopic observations
To obtain the Fundamental parameters
Dias de Nascimento eta., submitted
STSci Colloquium, October 6th 2010
Rotation distribution of young starsRotation distribution of young stars
11275, FGK dwarfs
3000 confirmed periods
Not compatible with a constant star formation rateExcess of young stars (also seen in Xrays)
Affer et al. A&A 506, 2009
Constant star formation rate
Age from gyrochronology
STSci Colloquium, October 6th 2010
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Activity IndexesActivity Indexes
= evolution time
H = activity index
(< 100 Hz)
Hulot et al.
~ P2 ?
Rossby number R= Prot/conv
H ~ R -1.5
STSci Colloquium, October 6th 2010
(H , Tc)
400 stars of the exofield + 30 from the sismofield
~
1/P(rot)
Sun
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Spot modelingSpot modeling
HD 49933P rot: 3.35 daysSpot life time: 2.5 to 3.5 daysSurface of the spots 3%Inclination 55° in agreement with seismology
STSci Colloquium, October 6th 2010
CP star HD 50773+spectropolarimetric observations
Mapping of surface inhomogeneities
A stellar cycle from seismology
HD 49933, F5V,
1.2 Mo, Rotation period 3.4 days
Observed twice for 400 days,
Modulation of seismic + activity indicators as in the Sun
around 120 days
Garcia et al., Science, Mathur
STSci Colloquium, October 6th 2010
The CoRoT exoplanet programmeThe CoRoT exoplanet programme
From light curves to complete planet characterisation……
A long way to go…….
Per run
10 000 targets 300 candidates
50 selected for FU obs 2 to 4 planets !
STSci Colloquium, October 6th 2010
15 +3 ?
CoRoT - 2CoRoT - 281 successive transits; Period: 1.742996 d; Radius: 1.465 RJ
Mass: 3.31 MJ; Rotation of the star 4.5 d
CoRoT - 6CoRoT - 615 successive transits; Period: 8.88 d; Rayon: 1.5 RJ
Mass: 3.3 MJ; Rotation of the star 6 d
Hot jupiters around very active stars
STSci Colloquium, October 6th 2010
CoRoT- 3bCoRoT- 3b
34 transitsPeriod 4.26 dRadius: 1.01Mass: 21.66Rotation of the star ~ 4 d
Between stars and planets
STSci Colloquium, October 6th 2010
CoRoT- 15bCoRoT- 15b
11 transitsPeriod 3 dRadius: 1.22Mass: 64
Deleuil et al. A&A 2008, 491, Bouchy et al. A&A accepted
A temperate gaseous planet
1.5 transit + WISE Photometry+ Harps Coralie spectroscopy..
Period 95 .27 days (145 days of observations)Transit duration 8.8 hours
Eccentricity 0.11G3V, not active, 0.9 Ms,
Rp= 1.1 Rjup, Mp= 0.84 Mj, Tsurf= 350K, H+ He+ 20mE rocks
CoRoT- 9CoRoT- 9
STSci Colloquium, October 6th 2010
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The smallest oneThe smallest one
scale 1/100 !
~ 170 transitsPeriod: 0.85 j
P rot: 23 jR= 1.7 Rearth
CoRoT-7b
STSci Colloquium, October 6th 2010
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Stellar activity and planet confirmationStellar activity and planet confirmation
CoRoT-7b A nightmare!
Strong noise due to stellar activity……Spot modeling confirms
0.85 days period exists, amplitude: 5m/sM= 4.5 M
Density ~ 5Silicates + water ?
second periodicity: 3.7 days, hot Neptune M= 9M
And a third one?
110 nights with HARPS:
STSci Colloquium, October 6th 2010
Conclusion…..?
1- Stars can be better understood 1- Stars can be better understood Looking carefully at their time dependant propertiesLooking carefully at their time dependant properties
* Seismology techniques* Seismology techniques* Non coherent behaviors* Non coherent behaviors
They are very diverse, more complex than the Sun, They are very diverse, more complex than the Sun, and more complex than we thoughtand more complex than we thought
Models have to be revised and improvedModels have to be revised and improved
2- Planetary systems are also very diverse2- Planetary systems are also very diverseTransit observations, complemented by spectroscopyTransit observations, complemented by spectroscopy
-->> some insight on their physics (density)-->> some insight on their physics (density)Models have to be revised and improvedModels have to be revised and improved
The major difficulty for the detection and charcaterisation The major difficulty for the detection and charcaterisation of small planetsof small planets
Is the stellar variabilityIs the stellar variability
3- Stars and planetary systems have to be studied together3- Stars and planetary systems have to be studied togetherCoRoT, Kepler, and later PLATO…….CoRoT, Kepler, and later PLATO…….
STSci Colloquium, October 6th 2010
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Thank you !
CoRoT data are public since december 2008Continuously pouring into the mission archive…
http://idoc-corot.ias.u-psud.fr
As soon as they are public at NStED
http://nsted.ipac.caltech.edu/NStED/docs/datasethelp/ETSS_CoRoT.html
Enjoy it !
The mission profile
december 27 2006 at 14:23:38 UT
1244 days in orbit
Intermediate size
mission
160 M$
600 kg
Polar orbit
at 896 km
0°
30°
60°
90°
120°
150°
180°
210°
240°
270°
300°
330°
0h2h4h6h8h10h12h14h16h18h20h22h
The CoRoT eyes
STSci Colloquium, October 6th 2010