pierre baudoz (paris observatory) a. boccaletti, d. mawet, j. schneider, g. tinetti, r. galicher, c....
TRANSCRIPT
Pierre BAUDOZ (Paris Observatory) A. Boccaletti, D. Mawet, J. Schneider, G. Tinetti, R. Galicher, C. Cavarroc J. Hough, P. Doel, D. Pinfield, C.-U. Keller, J.-L. Beuzit, S. Udry, M. Ferrari, E. Martin, F. Ménard , E. Sein, & SEE COAST Team …
ULg / CSL / LESIA / LUTH / LUAN / ETH-Zurich / IAP / Obs. Geneva / U. Bern / UCL / ROE / U. Hertfords. / MSSL / SRON / Astron / U. Utrecht / LAOG / ONERA / DLR / U. Vienna / U. Nantes / U. Torino / Astrium
Probing the Extrasolar Planet Diversity with
SEE COAST
SPICA MIR:Old EGPs
Direct Imaging Programs Overview
Space-based
Ground-based
1995 2000 2011 2017-20202008
SEE COASTVis/NIR: Old Jupiter+ Super Earth
Darwin/TPF-I MIR: Earth
TPF-CVis: Earth
JWSTNIR + MIR: Old EGPs
8m + XAOSPHERE / GPI / HiCIAONIR : EGPs young/massive/nearby
30/42m + XAOEPICS/ELTsNIR : EGPs intermediate Old + Super-Earth ?
>2025-30
HSTOpportunity for Space projects
In the Visible
mature giants & Super-Earths
8m + OAVLT, Keck,Gemini, Subaru
4m + OASilla, CFH
We already have targets !!!
From radial velocity surveys : From direct imaging :
More targets to come
• We can anticipate many RV planets at longer periods (giants and tellurics)
• A few accessible from SPHERE/GPI/HiCIAO (1. - 2.3 m) and JWST (2.5 - 28 m)
• Motivation for exploring a different spectral range (in the visible)
angular resolution AND contrast are required:
A small telescope in space can be optimized for exo-planetology
"Super Earth" as a sweet spot : brighter, earth-like notions apply (atmosphere, climate, variations, habitability, …)
What sort of astrophysics on these planets ?
Explore the Diversity with SEE COAST
- Spectra => Chemical composition
Burrows, Sudarsky
- Rayleigh scatterring => pressure, surf. reflectivity
• Spectroscopy
Explore the Diversity
• Spectroscopy• Polarimetry- Polarization=> Clouds / albedo
Jupiter-like planet - Stam et al. 2005Earth-like planet - Stam et al. 2008
cloud
vegetation
oceanA=0
A=1
Explore the Diversity
- Spectral time variation=> variation of temperature=> surface properties
0.45 m
0.75 m
- Polarimetric time variation => surface properties
Cloud free Earth from 0.65 to 0.9 m
50° Phase angle
130°90°
• Spectroscopy• Polarimetry• Variability
Which targets ? (contrast + IWA requirements)
short wavelengths are optimal
longer wavelengths require small IWA coronagraph (2/D)
near IR (1 - 1.2 m)- self luminous planets - T > 800K
10-10 contrast required
A proposal to Cosmic Vision …
✔Submitted in 2007 to ESA Cosmic Vision
Parameter Value
Entrance pupil diameter D > 1.5m
Angular resolution 70 mas @ 0.6 m
Spectral Range 0.4 to 1.2 m
Spectral Resolution R>40
Contrast (after speckle subtraction) @ 2 /D
< 10-9
Contrast (after speckle subtraction) @ 4 /D
< 10-10
Orbit for 6 months visibility, high thermal stability
L2 Lagrangian
Hyperbolic secondary mirror 4,85 m long
Parabolic primary mirror
Two folding mirrors
Focal plane
Coronagraphy: Multi 4QPM
Baudoz et al. 2007, 08
laboratory planetContrast :6.7 10-9bandwidth 20%
Multi 4QPM : Meudon
N phase masks in series => Improves bandwidth as ^NPupil
Telescope
FQPM # 1
FQPM # 3FQPM # 2
Wavefront correction : Coherence
Speckle nullingin a limited FOV with a DM (JPL)
Summary
SEE COAST requires : • High contrast : ≈ 10-10 AND small IWA : ≈ 2 /D
SEE COAST can get : • low res spectra of mature giants < 20pc (< 8 - 10 AU)• colors of a few mature Super Earths < 10pc (< 4 - 5 AU)• possibly Earths around the nearest star ( Cen)• low res spectra of self luminous planets (extension to near IR)
SEE COAST is : • Compatible with general astrophysics (pushing to UV, wide field ?)• Compatible with transit spectroscopy
– additional targets (unresolved planets) & complements IR transit characterization programs
Next steps in the project :• refine some science cases and simulations (statistical analysis) • elaborate optical design with industrial partners (Astrium) + derive tolerances • technological developments in coronagraphy and wavefront control• get prepared for next COSMIC VISION proposal (2010)