Development of Space Infrared Coronagraph toward Direct Observations of Extra Solar Planets

太阳系外行星的直接观测是天文学的重要课题之一，它与我们的宇宙学密切相关，可以为我们提供行星形成和演化的线索，以及它们的多样性，并最终提供地外生命的证据。然而，中心恒星和行星之间的高对比度给观测带来了挑战。为了解决这个问题，我们一直在努力开发一种恒星日冕仪。利用该仪器，在不受大气影响、对比度良好的红外光谱范围内，从太空直接观测太阳系外行星，在前所未有的高对比度演示试验、波阵面补偿的开发、红外实验环境的冷却试验等方面取得了具体成果。我们的这些成就为将来从太空观测太阳系外行星奠定了基础技术。

Direct observation of extra solar planets is one of the key subjects of astronomy, which are linked to our cosmology : That can offer us clues to formation and evolution of planets, their diversity and ultimately evidence of extra-terrestrial life.However, high contrast between the central stars and planets poses a challenge to the observation. To address the problem, we have been working on developing a stellar coronagraph. With the instrument, we aim to directly observe extra solar planets from the space in the infrared spectral range, which gives us condition free from atmospheric influence and favorable in contrast.Consequently, we have achieved concrete results in a demonstration test of unprecedentedly-high contrast, development of wavefront compensation, and a cooling test in the infrared experimental environment. These achievements of ours established basic technology for observation of extra solar planets from the space in the future.