Telescope T-170M

The T-170M telescope provides an accessible field of view of 30 arcmin on the telescope focal plane and the optics is diffraction limited at 200 nm. The main characteristics of the T-170M are summarized table below. The optical system is close orthoscopic; the maximum image distortion is only about 0.06%.

Optical System Ritchey-Chrétien
Aperture diameter 1.7 m
Focal length 17 m (primary mirror)
f/# 10.0
Field of View (FoV) 30 arcmin (150 mm in diameter)
Wavelength range 115-600 nm
Primary Wavelength 200 nm
Optical quality Diffraction limited at FoV center
Angular resolution on focal plane 12.13 arcsec/mm
Mass 1570 kg (1600 kg with adapter truss)

5.67 x 2.30 m (transport)

8.43 x 2.3 m (operational)

In the instruments compartment, the optical bench – used as reference plane for all the onboard instrumentation – is aligned and maintained in the correct position with respect to the primary mirror using a three rods system. The FCU is mounted on the upper basis of the optical bench, in the space available between the primary mirror and the optical bench itself, while WUVS is mounted to the optical bench bottom basis. The Fine Guiding Sensors (FGS) are also mounted on the focal plane. The sensors are placed at the vertex of an equilateral triangle in the focal plane close to the spectrograph entrance slits, ensures a pointing stability 0.1 arcsec. Each of the focal plane instruments has its own power supply and data handling unit in a service box mounted on the external side of the instrument compartment.

Assembling and pointing of the optical system