OAO::Okayama Astrophysical Observatory/NAOJ | About The 188cm Telescope (original) (raw)
The 188cm telescope is the largest telescope in Japan. It was the seventh largest telescope in the world and the largest telescope in the eastern world at the time of its foundation. It took abount 5 years and cost 300 million dollers at the time to construct the telescope and its enclosure. This telescope has several sisters (i.e same type of telescopes construted by Grabb Persons Inc.) in the world; in Canada, in Australia, in France, in Egipt, and in South Africa.
Specifications
Basic spesifications
Latitude
+34° 34′ 37.47” N
Longitude
133°35’38.24″ E
Altitude
372m
Telescope type
Classical Type Cassegrain(constructed by Grabb Persons Inc., UK in 1960)
Mounting
British-type equatorially mounting
Weight
50t
Length
9m (center piece + octagonal torus)
Haltmann constant
about 0.23
Pointing accuracy
about 20 arcsec
Primary mirror
Focal length
9.15m F/4.9
Material
Pylex
Thickness
27cm
Weight
1.7t
Surface shape
Paraboloid
Secondary mirror(Material : fused quartz)
Diameter [mm]
Weight [kg]
Surface
Paraaxial radius [mm]
Newton
533.4
41
Flat
—
Cassegrain
507.88
34
Hyperboloid
5937.50
Coude
507.88
34
Hyperboloid
5171.39
Focus
Focal length [m]
Focal ratio
Plate scale[“/mm]
Newton
9.15
4.9
22.5
Cassegrain
33.85
18
6.09
Coude
54.29
29
3.80
Guide telescope
Diameter
15cm
Focal length
150cm
Field of view
1.18deg
Anecdote
The 188cm telescope impacted on people in Japan 46 years ago. A boy who saw some parts of the telescope being transported from Tamashima bay of Kurashiki city to Chikurin-ji mountain became an astronomer later, and he is still an active astronomer.