Proposal for a project of high-precision stellar radial velocity work, Struve (1952)! But there seems to be no compelling reason why the hypothetical stellar planets should not, in some instances, be much closer to their parent stars than is the case in the solar system.
高温下(T>2000 K)の地球型惑星 Magma Ocean Planet Close-in Rocky Planet Star
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SiO simulation SiO K Na Fe simulation Water Vapor
大規模蒸発惑星? : 地球質量/Gyr の散逸 Bump Rappaport et al. (2012) Tail
中温域(500K<T<2000K)の岩石惑星 Inner Rocky Planet Star
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Planetary Radial Velocimetry! 1. (R~10 5 )! ~50 CO lines v=110 ± 3 km/s! (VLT/CRIRES: R~87,000) 2. S/N (N > 50) blue shift Observer red shift Brogi et al. 2012, Nature 486, 502
Spectroscopic Coronagraph 2 1 Extreme Adaptive Optics /D 0-1 Visible Nuller -pi/2 +pi/2-2 -2-1 0 1 2 /D mock 55 Cnc b! a=0.11 au! d=12.3 pc! 2.3 micron (CO)! Instant images for 0.5 msec D = 30m! Kawahara, Murakami, Matsuo, Kotani 2014
Extreme Adaptive Optics PSF size Contrast 50倍改善! S/N は~3倍改善! Star Visible Nuller -pi/2 Planet (口径が3倍と同じ)! +pi/2 Instant images for 0.5 msec A planet is unresolved but stellar photons are reduced Kawahara, Murakami, Matsuo, Kotani 2014
低温下(T 300K)の岩石惑星 Star Earth-like Planet
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Reflec%on Spectra of Earthshine Courtesy of E. Palle 1.0 1.0 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 O 2 O 2 O 2 (1.27μm) No strong abiotic sources! (not always true) 0.5 1.0 1.5 2.0 0.5 1.0 1.5 2.0 Wavelength (μm) Wavelength (micton)
CO2 >CH3COO - CO2 >CH4 S >HS - SO4 2- >HS - HS - > S HS - > SO4 2- Fe 3+ >Fe 2+ O2 >H2O Fe 2+ >Fe 3+ H2O > O2 electron acceptor electron donor
Semimajor axis of Habitable Zone incoming energy outgoing radiation 0.1 AU 1 : 10-8 1 AU 1 : 10-10 Planet-Star Contrast in HZ for a fixed Tp i.e.
Contrast ~ 10-10! TPF-type space missions [ ] GJ 832c Contrast ~ 10-8! Ground-based 30 m class telescope [AU]
1 0 0 0 0 0 1.0 0.8 0.6 0.4 0.2 O 2 O 2 O 2 (1.27μm) 0.5 1.0 1.5 2.0 Wavelength (μm)
Planet - Star Contrast 7 10-7 8 10-8 5Σ O 2 1.27Μm 5hrs S N 10 10 S N 5 5 S N 3 3 S N 1 Planet Detection J band 1 hour M K G F 5Σ 5Σ Crossfield 2013 5Σ 9 10-9 5Σ 0 10-10 Photon noise limited IFS Kasper 10 EPOL Kasper 10 ~ 7 pc 1 10-11 5 10 50 100 Angular 500 100Separation [mas]
Expected number from Kepler results by I. Crossfield (2013) MNRAS
Spinrad et al. (1963)! Doppler-shifted Water Vapor! in Martian Reflection Spectra Stacked H2O lines! 817.697 nm, 818.927 nm,! 822.696 nm, 828.202 nm
Benchmark test using a simulated Earth-twin F speckle : F p 2000 : 1 CCF molecular binary template
ExAO+Coronagraph (raw contrast = 10-5 )! + High-d spectroscopy (R = 50,000) Water for line intensity = 10-24 -10-22 cm2/cm Oxygen 1.27 micron (J band)