SEIMEI Telescope (Okayama Obs.)
|3.8-meter SEIMEI Telescope was completed
Kyoto University Astronomical Observatory and Department of Astronomy completed
installation of a new 3.8-meter diameter optical-infrared alt-azimuth mount telescope (now
named Seimei Telescope) into the telescope dome on the summit area of Mt. Chikurinji
(366 meter) in the southwest region of Okayama prefecture, between Asakuchi-city and
Yakage-town. A press conference was held on August 17, 2018 to commemorate the
completion of the dome structure.
The original development of a new telescope that resulted as Seimei Telescope began in
the early 2000s. The construction of the dome structure began in 2016, and after three
years Seimei Telescope achieved a great milestone with its mirror segments installed on
the telescope itself in the summer of 2018.
Seimei is a distinguished telescope whose construction makes use of three techniques
First is the petal-shaped segmented mirror design for the primary
mirror. The segmented mirror design is widely used by telescopes around the world, from
the one of the largest ground-based telescopes 10-meter Keck twin telescopes (ref1) to
recently the NASA/James Webb Space Telescope (to be launched on March 2021, ref2),
and hexagon-shaped segment mirrors are typically used.
Seimei would be the world's first
telescope with the primary mirror assembled from eighteen petal-shaped mirror segments.
The optical characteristics of Seimei Telescope with the petal-shaped segments are
supposed to be superior to telescopes with hexagon segments.
Second is the ultra-precision mirror grinding technology. It usually takes quite a long time
and needs great cost to polish mirrors made from glass-ceramic material at high precision.
For the case of the 8.2-meter primary mirror for Subaru Telescope of National
Astronomical Observatory of Japan (ref3) at the summit of Mauna Kea, it took four years to
complete primary mirror polishing (ref4). However, we successfully reduce the amount of
time significantly, needed for shaping and polishing these mirror segments by
incorporating our own ultra-precision mirror grinding technique.
Third is the light-weight telescope alt-azimuth mount. In order to observe the sky efficiently,
Seimei Telescope needs to be able to point to any target objects within a very short
amount of time. To do so, Seimei Telescope is built upon a light-weight but durable
structural design. We were able to reduce the total weight of the telescope structure by
adopting arc-like railings and truss structure to support the primary mirror segments and
the telescope itself and optimizing the telescope design with a genetic algorithm.
Each of these technologies was developed specifically for Seimei Telescope on our own.
Last but not least, the development of Seimei Telescope itself was also a significant task to
achieve the project.
As of December 2018, we are giving final touches to the optical/mechanical/electronic
sections of Seimei Telescope and fine-tuning the supporting software for telescope
operations. We expect the first light of Seimei Telescope very soon, and the science
operation will commence soon thereafter. Seimei Telescope will be one of the workhorses
in 2020s astronomy. We look forward to making breakthroughs with our own Seimei