About The 188cm Telescope
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.
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