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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.

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Outline

Direct Imaging of Extrasolar PlanetsOverview of Ground & Space ProgramsAnthony Boccaletti : Obs. Paris-Meudon


Outline

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

No longer a dream !

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

A few more last week …


Problematic

Problematic

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

Planets are faint and close ….

109 = 1 milliard

106 = 1 million

Reflected light

Thermal emission


Problematic1

Problematic

Stellar images are not point-like …


Solutions to reduce diffraction

Solutions to reduce diffraction

We need BIG telescopes …

We need to attenuate the star

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


In theory

Plan A:

si

Plan B:

Plan C:

Plan D:

In Theory …


We are working on it

We are working on it ..


Problematic again

Problematic (again)

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

JPL Testbed

SCC simulation

SDI, Gemini

ADI, Gemini

SD, VLT

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)


Planned projects

Planned Projects


Planet finders on 8m telescopes 2011

Planet Finders on 8m telescopes (2011)

eXtreme AO + coronagraphy + differential imaging

HiCIAO

European Consoritum, VLT

- Dual band NIR camera (YJHK)

- NIR IFS (YJH)

- Dual Polarisation VIS camera

  • Japan, 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


James webb space telescope 2014

US instrument

0.6 - 5 m imager

NIRCAM has 5 coronagraphs

Optimized for several filters (F200, F480, …)

Good performance at 4.8m

At 2.2 m mature giants are too faint.

Expected contrast : 105 - 106

- photometry (R=10-20)

l=11.40mm

James Webb Space Telescope (2014)

MIRI

& SPICA

NIRCAM

MIRI

Europe + US consortium

5 - 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)

FGS - TFI

CSA responsabilty

1 - 5 m tunable filter

with coronagraphic capabilities

(Spectral Deconvolution)

- spectra (R=100)


Extremely large telescopes 2020

Extremely Large Telescopes (2020)

heritage of SPHERE / GPI / HiCIAO

/D = 10mas- Photometry + spectra

heritage of VIZIR & MIRI

/D = 50mas

Photometry + spectra

objectives :

- young giants

- mature giants, spectral characterization

- Super Earth : detection + 1st order charac.

  • objectives :

  • mature giants

  • irradiated planets


Future projects in space

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

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

Two spacecrafts: towards tellurics

External Occulter

Fresnel imaging lens

Occulter : 50 m

Telescope : 4 m

Separation : 80 000 km

Optimize for Vis. and UV : 0.4 -1.1 m

Chromatic

High throughput

Lens : 3.6 m

Telescope : 68 cm

Separation : 2.5 - 20 km

Optimize for Vis. and UV : 0.1 -1 m

Chromatic

Low throughput


Timeline

HST

Vis

JWST

NIR + MIR

old / close EGPs

2014

1995

2000

2007

2011

2017-2020

4m + AO

Silla, CFH

NIR

30 - 40 m + XAO

EPICS / PFI

NIR + MIR

old EGPs / Super Earth

8m + XAO

SPHERE / GPI / HiCIAO

NIR

young / massive / close EGPs

8m + AO

VLT, Keck, Gemini

NIR

Timeline

SPACE

Room for missions !

Vis / MIR

- old EGPs

- Super Earths

- Earths

GROUND


Mass vs wavelength coverage

Mass vs. Wavelength coverage

Space telescopes

10 MJ

1 MJ

Space

Interferometry

10 M

Occulters

1 M


A few conclusions

A few conclusions …

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

see the talks of this afternoon for details

most instruments focused on EGPs in the NIR & MIR

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

What’s next (short timescale) :

- spectroscopy of EGPs in the visible

- Super Earths are numerous

- MIR : space interferometry more promising (see talk this afternoon)


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