Primary mirror diameter
|
508 mm
|
Primary focal ratio
|
F/3
|
Secondary mirror diameter
|
192 mm
|
Equivalent focal ratio
|
F/8
|
Equivalent focal length
|
4000 mm
|
Back Focus (from primary mirror surface)
|
355 mm
|
Primary to Secondary Spacing
|
994 mm
|
Mirrors material
|
LK-7 (optical glass with low linear expansion coefficient). By preliminary agreement, the optics made of AstroSitall can be installed
|
Accuracy of the optics manufacturing
|
RMS deviation of wave front is no more than 0.04λ, Strehl criterion is no less than 0.95. The optics quality interferometric certificate is attached to every telescope
|
Focal plane position
|
225 mm from the rear end of the tube
|
External thread on the backside connecting flange
|
M 126x1.25. It is used for mounting field rotator, adapter rings, and other equipment
|
Internal thread on the backside connecting flange
|
M 111x1. It is used for mounting the ASTROSIB FFC20 corrector
|
Outer dimensions
|
640x688x1450 mm (the length 1150 mm is presented without regard for the installing of adapters and receiving equipment)
|
Mass of the telescope
|
68 kg
|
