Subaru Seminars



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Subaru Seminars are usually held in Room 104 of the Hilo Base Facility, adjacent to the main lobby. Everyone is welcome to attend. If you would like to give a seminar, please contact Subaru seminar organizers (Hyewon Suh, Tae-Soo Pyo, Nagayoshi Ohashi) by email : sseminar_at_subaru.naoj.org (please change"_at" to @).

July 8, Monday, 11am in 104A

Secret of Mauna Kea, Secret of Subaru - ADC, The Heart of Subaru Telescope

Kyoji Nariai (NAOJ)


The Subaru Telescope has done amazing work with its Prime-Focus-Camera. In the first 10-15 years we used SuprimeCam, and more recently Hyper SuprimeCam (HSC). Most of you know that the combination of the Subaru Telescope and HSC has produced extraordinary images of great size and quality. But do you know of the existence of the Atmospheric Dispersion Corrector (ADC) in the middle of the camera, and how it works? The image of a star made by an ordinary camera is elongated, and becomes like a rainbow, due to the effects of the atmosphere. This distortion is a strong function of the zenith distance to the star, and so we do not usually recognize changes in this distortion because the focal length of a camera is usually short. But with a big telescope like Subaru, whose focal length is 15m, it matters. We need to design a specialized camera in order to compensate for this atmospheric diffraction. As the first man to design a camera for JNLT, I used two direct-vision prisms for ADC and I boasted to be the designer of the largest camera in the world. But it did not last long. Kunio Takeshi of CANON company invented a sliding type ADC and made a better design of SC. In this seminar, I will explain how the Atmospheric Dispersion Corrector invented by late Dr. Takeshi works.


Seminars are also held at JAC, CFHT, and IfA.



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