The Solar Optical Telescope of Solar-B ( Hinode): The Optical Telescope Assembly
Kubo, M.; Ichimoto, K.; Tsuneta, S.; Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Tamura, T.; Hara, H.; Takeyama, N.; Otsubo, M.; Nakagiri, M.; Noguchi, M.; Matsushita, T.; Kawaguchi, N.; Saito, H.; Mikami, I.; Kato, Y.; Yamamuro, T.; Shimada, S.; Nakaoji, T.; Nagae, K.
Japan
Abstract
The Solar Optical Telescope (SOT) aboard the Solar-B satellite (Hinode) is designed to perform high-precision photometric and polarimetric observations of the Sun in visible light spectra (388 - 668 nm) with a spatial resolution of 0.2 - 0.3 arcsec. The SOT consists of two optically separable components: the Optical Telescope Assembly (OTA), consisting of a 50-cm aperture Gregorian with a collimating lens unit and an active tip-tilt mirror, and an accompanying Focal Plane Package (FPP), housing two filtergraphs and a spectro-polarimeter. The optomechanical and optothermal performance of the OTA is crucial to attain unprecedented high-quality solar observations. We describe in detail the instrument design and expected stable diffraction-limited on-orbit performance of the OTA, the largest state-of-the-art solar telescope yet flown in space.