SPICA Coronagraph Instrument (SCI) for the Direct Imaging and Spectroscopy of Exo-Planets

¹ ISAS/JAXA, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan
² Department of Space and Astronautical Science, The Graduate University for Advanced Studies, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan
³ Department of Physics, Graduate School of Science, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
⁴ Institute of Astronomy, School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015, Japan
⁵ National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181- 8588, Japan
⁶ Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
⁷ Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
⁸ Department of Information Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka, Kanagawa, 259-1293, Japan
⁹ Division of Applied Physics, Hokkaido University, Sapporo 060-8628, Japan
¹⁰ Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan, R.O.C.
¹¹ Jet Propulsion Laboratory, Pasadena,CA 91109, USA
¹² Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
¹³ Laboratoire A.H. Fizeau, Université de Nice Sophia-Antipolis, CNRS, Parc Valrose, 06108 Nice Cedex 02, France
¹⁴ Subaru Telescope, National Astronomical Observatory of Japan, 650 North A’ohoku Place, Hilo, HI 96720, USA
¹⁵ Observatoire Astronomique de Marseille-Provence, Pôle de l’Etoile Site de Château-Gombert 38, rue Frédéric Joliot-Curie, o a ee 13388 Marseille cedex 13 France
¹⁶ Optcraft Corp., 3-16-8-101, Higashihashimoto, Sagamihara, Kanagawa, 229-1104, Japan

Abstract

We present the SPICA Coronagraph Instrument (SCI) for the direct imaging and spectroscopy of exo-planets.

The SPICA mission gives us a unique opportunity for high-contrast observations because of the large telescope aperture, the simple pupil shape, and the capability for infrared observations from space. The primary target of SCI is Jovian exo-planets. Using the spectroscopy mode of SCI, we will try the detection and the characterization of mid-infrared line features of the atmosphere of exoplanets. The specifications, performance and the design of the instrument are shown. The main wavelengths and the contrast required for the observations are 3.5–27 μm, and 10^-6 , respectively. We also show the progress of the development of key technology to realize SCI. Laboratory demonstration of the principle of coronagraph, realistic design and fabrication of masks, and the development of cryogenic active optics have been carried out, or are successfully ongoing. We are preparing a cryogenic chamber for the tests of the whole infrared coronagraph. A potentially important by-product of the instrument, transit monitoring for characterization of exo-planets, is also described. We expect that SCI will provide drastic progress in the understanding of various planetary systems and will be a unique capability in the SPICA era.