Planetscope: an exoplanet coronagraph on a balloon platform

Direct detection of mature exoplanets is possible using a visible-wavelength telescope and coronagraph in the stratosphere. We analyze two sources of dynamic wavefront perturbations: turbulence in the free atmosphere and locally generated turbulence. We find that they are expected to have relatively small effects on the wavefront. We find that neither source should limit observations at 10-9 contrast levels for planet-star separations of 0.5 arcsec. On this basis, we expect that it is feasible to image and characterize several known radial-velocity exoplanets.

[1]  A. S. Gurvich,et al.  Parameters of the fine density structure in the stratosphere obtained from spacecraft observations of stellar scintillations , 2003 .

[2]  J. Borgnino,et al.  Estimation of the spatial coherence outer scale relevant to long baseline interferometry and imaging in optical astronomy. , 1990, Applied optics.

[3]  A. Nuttall.  Some windows with very good sidelobe behavior , 1981 .

[4]  R. A. Silverman,et al.  Wave Propagation in a Turbulent Medium , 1961 .

[5]  A. Gurvich,et al.  Estimates of characteristic scales in the spectrum of internal waves in the stratosphere obtained from space observations of stellar scintillations , 2005 .

[6]  Jack D. Gaskill,et al.  Linear systems, fourier transforms, and optics , 1978, Wiley series in pure and applied optics.

[7]  Laurent Jolissaint,et al.  Optical Turbulence Generators for Testing Astronomical Adaptive Optics Systems: A Review and Designer Guide , 2006 .

[8]  J. Goodman.  Statistical Properties of Laser Speckle Patterns , 1963 .

[9]  A. Gurvich,et al.  Study of the turbulence and inner waves in the stratosphere based on the observations of stellar scintillations from space: A model of scintillation spectra , 2001 .

[10]  John Vanderkooy,et al.  Correction to "Resolution Below the Least Significant Bit in Digital Systems with Dither" , 1984 .

[11]  Pietro N. Bernasconi,et al.  The solar bolometric imager , 2002 .

[12]  一岡 芳樹,et al.  J. D. Gaskill: Linear Systems, Fourier Transforms, and Optics, John Wiley & Sons, New York, 1978, xiv+554ページ, 23.5×15.5cm, $24.96 (Wiley Sons in Pure and Applied Optics). , 1979 .

[13]  O. Guyon.  LIMITS OF ADAPTIVE OPTICS FOR HIGH-CONTRAST IMAGING , 2005, astro-ph/0505086.

[14]  S. Ridgway,et al.  Exoplanet Imaging with a Phase-induced Amplitude Apodization Coronagraph. III. Diffraction Effects and Coronagraph Design , 2006 .

[15]  D. G. Peterson,et al.  ZEEMAN LASER INTERFEROMETER , 1966 .

[16]  Anna Consortini,et al.  Estimate of characteristic scales of atmospheric turbulence by thin beams: Comparison between the von karman and hill-andrews models , 2004 .