16 - 21 June 2024
Yokohama, Japan
Conference 13094 > Paper 13094-115
Paper 13094-115

The University of Tokyo Atacama Observatory 6.5-m telescope: screen camera system for the telescope mirror alignment

On demand | Presented live 18 June 2024

Abstract

Measurement of the alignment error of the telescope mirrors is an essential and demanding task in the telescope assembly phase. One method is to examine the aberration over the whole telescope field of view from sky images with stars, but there are complicated issues in the case of large telescopes. The focal plane of the University of Tokyo Atacama Observatory (TAO) 6.5m telescope has a large diameter of 546mm and a field curvature. Therefore, many imaging sensors must be arrayed on the curved focal plane. We propose a concept of a screen camera for the TAO 6.5m telescope. To lower the cost, we accept the degradation of the spatial resolution up to ∼2 arcseconds and the decrease in optical throughput. This system consists of a transparent screen, a camera lens, and a CMOS sensor, and it obtains sky images through the telescope on the screen. The transparent spherical screen with one side sanded is placed at the telescope focal plane. A CMOS sensor with a commercially available camera lens and filters is placed at about 1.5 meters from the screen and captures the starry sky on the screen. The pixel scale on the CMOS sensor is calculated to be 0.31 arcseconds, and the estimated limiting magnitude is about 13 in a 10-second exposure at a 10σ level. After the telescope mirror alignment, the screen camera will provide focused sky images in the whole field of view, 25 arcminutes diameter.

Presenter

Kazuya Matsubayashi
The Univ. of Tokyo (Japan)
Kazuya Matsubayashi is an assistant professor at the Institute of Astronomy at the University of Tokyo. He earned an M.S. and Ph.D. in physics from Kyoto University. His work focused on developing an optical integral-field spectrograph KOOLS-IFU and a multi-band imager and spectrograph TriCCS for a 3.8-m optical-near infrared telescope at Okayama, the Seimei telescope. He belongs to the University of Tokyo Atacama Observatory (TAO) Project and contributes to assembling the 6.5-m telescope mirrors and constructing a new optical instrument. Because he recently moved to Tokyo, touring the neighborhood by bicycle is his weekend hobby.
Presenter/Author
Kazuya Matsubayashi
The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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Mamoru Doi
The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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National Astronomical Observatory of Japan (Japan), The Univ. of Tokyo (Japan)
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Fumi Egusa
The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)
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Kosuke Kushibiki
The Univ. of Tokyo (Japan)
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Natsuko Kato
The Univ. of Tokyo (Japan)
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The Univ. of Tokyo (Japan)