molecules in the atmosphere of extrasolar planets, paris, 19-21 nov. 2008 1 direct imaging of...

1Molecules in the atmosphere of extrasolar planets, Paris, 19-21 nov. 2008

Direct Imaging of Extrasolar Planets

Overview of Ground & Space Programs

Anthony Boccaletti : Obs. Paris-Meudon


Outline

1. A brief introduction to the high contrast imaging problematic

2. A brief review of projects (talks to follow)

4. « Where » do we need to direct our effort


No longer a dream !

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2M1207 5 MJ 46 AU

GQ Lup 17 MJ 100 AU

AB Pic 14 MJ 248 AU

CHRX73 12 MJ 210 AU

HN Peg 16 MJ 795 AU

DH Tau 12 MJ 330 AU

RSX 1609 8 MJ 330 AU

Detection was made possible because :

- small mass ratios (contrast is lower)- young ages (planet is brighter)- large physical / angular separations


A few more last week …



Fomalhaut < 3 MJ 120 AU

HR8799 b 5 MJ 46 AU

HR8799 c 12 MJ 330 AU

HR8799 d 8 MJ 330 AU


Problematic

Planets are faint and close ….

109 = 1 milliard

106 = 1 million

Reflected light Thermal emission

STOP !!!! … What about diffraction ???


Problematic

Stellar images are not point-like …


Solutions to reduce diffraction

Yes but … the Sun is an extended source

Stars are point sources => diffraction is much stronger

We need more performant stellar coronagraphs … to attenuate stars

We need BIG telescopes …

We need to attenuate the star


In Theory …

€

ψA = A.e iϕ

€

ψA = A

€

ϕ =0siPlan A:

Plan B:

€

ψB =ψ A ⇒ ψ A .M

Plan C:

€

ψC =ψ B =ψ A ⊗M ⇒ ψ A ⊗M( ).D

Plan D:

€

ψD =ψC = ψ A .M( )⊗D


We are working on it ..


Problematic (again)

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Instruments are not perfect …. unfortunately

Many defects :

- atmospheric turbulence for ground based telescopes- static (more or less) optical aberrations- variation of transmission- alignment- chromaticity- …

=> Limits the performance of coronagraphs


Solutions to reject speckles

Wavefront Correction :at focal plane - speckles minimization - Self Coherent Camera

Wavefront Calibration :Differential imaging

- spectral (SDI, SD)- angular (ADI)- polarimetric (PDI)



JPL Testbed



SCC simulation



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SDI, GeminiSDI, Gemini



ADI, GeminiADI, Gemini



SD, VLTSD, VLT


Planned Projects


Planet Finders on 8m telescopes (2011)

European Consoritum, VLT

- Dual band NIR camera (YJHK)- NIR IFS (YJH)- Dual Polarisation VIS camera

eXtreme AO + coronagraphy + differential imaging

HiCIAOJapan, Subaru

- Dual band NIR camera- Dual polarisation NIR camera

HiCIAO + (in dev., 2010)- Focal Plane WF- coronagraph improvement- NIR IFS



US, Gemini South

- NIR IFS (YJH)Focal Plane

Looking at Giant Planets in : - young associations of stars (10 Myrs <100pc) - stars with known planets (RV surveys)- stars of intermediate age (0.1-1 Gyr)- very nearby bright stars


MIRIEurope + US consortium5 - 28 m imager + IFU

MIRI imager has 4 coronagraphs

4QPM in 3 filters (10.6, 11.4, 15.5 m) => self luminous mature giants T > 300-400K (5 - 10AU, 10pc, 5Gyr)

Expected contrast : 104 - 105

- photometry (R=20)

James Webb Space Telescope (2014)

=11.40m

CSA responsabilty 1 - 5 m tunable filterwith coronagraphic capabilities(Spectral Deconvolution)- spectra (R=100)



US instrument0.6 - 5 m imager

NIRCAM has 5 coronagraphs Optimized for several filters (F200, F480, …)

Good performance at 4.8mAt 2.2 m mature giants are too faint.

Expected contrast : 105 - 106

- photometry (R=10-20)

NIRCAM

MIRI

FGS - TFI

& SPICA




Extremely Large Telescopes (2020)

objectives : - mature giants- irradiated planets

heritage of VIZIR & MIRI



/D = 50masPhotometry + spectra

heritage of SPHERE / GPI / HiCIAO

/D = 10mas - Photometry + spectra

objectives : - young giants - mature giants, spectral characterization- Super Earth : detection + 1st order charac.


Future projects … in space

Extend spectroscopic characterization towards ;

- shorter wavelengths (<1 m)- lower masses (Super Earths, Earths)- shorter separations (< 1 AU)- older objects (1 - 5 Gyr)- more distant stars (> 100 pc)- …




Single spacecraft (later than 2020)

Small Telescopes : 1.5 - 2m

- optical quality - efficient coronagraph - focal plane WFS and correction- differential imaging

3 studies in the US :- PECO- ACCESS => Probe Class (Decadal Survey)- EPIC- SEE-COAST => CV proposal

- spectra : 0.4 - 1.0 m (R>50)- polarimetry : 0.4 - 0.85 m

objectives :- explore diversity of planets- mature giants in the visible- Super Earths- target list : HARPS, ESPRESSO, GAIA, COROT, KEPLER, …


Two spacecrafts: towards tellurics



External Occulter Fresnel imaging lens





Occulter : 50 mTelescope : 4 mSeparation : 80 000 kmOptimize for Vis. and UV : 0.4 -1.1 mChromatic High throughput

Occulter : 50 mTelescope : 4 mSeparation : 80 000 kmOptimize for Vis. and UV : 0.4 -1.1 mChromatic High throughput

Lens : 3.6 mTelescope : 68 cmSeparation : 2.5 - 20 kmOptimize for Vis. and UV : 0.1 -1 mChromaticLow throughput

Lens : 3.6 mTelescope : 68 cmSeparation : 2.5 - 20 kmOptimize for Vis. and UV : 0.1 -1 mChromaticLow throughput


Timeline

SPACE

GROUND

Vis / MIR - old EGPs- Super Earths- EarthsJWST

NIR + MIR old / close EGPs

8m + XAOSPHERE / GPI / HiCIAONIRyoung / massive / close EGPs

30 - 40 m + XAOEPICS / PFINIR + MIRold EGPs / Super Earth

8m + AOVLT, Keck, GeminiNIR

4m + AOSilla, CFHNIR

Room for missions !

1995 2000 2011 2017-20202007 2014



HSTVis


Mass vs. Wavelength coverage

1

10

100

1000

10000

0,1 0,2 0,4 0,6 0,8 1 1,2 1,6 1,8 2 2,2 2,5 3 5 10 15 20

lambda ( )m

Earth masses

SPHERE GPI

HiCIAO

EPICSEPICSPFIPFI

MIRI MIRISPICASPICANIRCAM

Spa

ce te

lesc

opes

Occulters

Spa

ce

Inte

rfer

o met

ry

10 MJ

1 MJ

10 M

1 M


A few conclusions …

1. high contrast imaging allows to study molecules in the atmosphere of a wide variety of objects

2. see the talks of this afternoon for details

3. most instruments focused on EGPs in the NIR & MIR

4. There is a gap between EGPs and Earth-like planets spectrocopy

5. What’s next (short timescale) :- spectroscopy of EGPs in the visible

- Super Earths are numerous- MIR : space interferometry more promising (see talk this

afternoon)

molecules in the atmosphere of extrasolar planets, paris, 19-21 nov. 2008 1 direct imaging of...

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