|VLT Survey Telescope Center at Naples Web Portal|
Submitted by administrator on Wed, 2006-05-31 11:08.
The VST optics has been designed at INAF-OAC by Technology Working Group (TWG) in collaboration with ESO. The peculiarity of this telescope optics is that it is provided with two switchable correctors, for observations at different observing angles:
a two-lens corrector and ADC (Atmospherical Dispersion Corrector) plus one different lens corrector.
The VST optics were procured through a contract with Carl Zeiss Jena GmbH, with the Russian firm LZOS JSC as subcontractor. The primary (M1) and secondary (M2) mirrors are made from Sitall, an optical glass produced by LZOS JSC and similar to Zerodur.
The lenses for the WF correctors are of fused silica produced by Schott.
In 2002 the primary mirror was destroyed in an accident during shipment from Europe to Chile. This enforced a series of emergency actions to resolve the problem with minimum impact on the final VST schedule. The new contract with the LZOS JSC envisages the supply of the replica mirror at the end of August of 2005. It is expected that the new M1 shall maintain the outstanding quality figures measured on the original mirror. M2 was also slightly damaged during transportation to Chile, and has been returned to LZOS JSC for repair.
The VST is optimized for seeing-limited spatial resolution over a field of view of 1° x1° matched to a 16k x16k pixels CCD mosaic camera. It operates two different correctors: the first, consisting of two lenses, works in the range from 320 nm to 1014 nm for observations at small zenithal distances; the second, composed of a rotating ADC coupled to one lens only, operates in the range from 365 nm 1014 nm down to an elevation of 30°. A mechanical switching unit allows the appropriate corrector to be selected.
M1 + M2 (f/5.5)
( categories: Telescope )
VST + OmegaCam Exposure Time calculator
Description: VOCET is a versatile calculator allowing the observer to compute various quantities related to the VST + OmegaCam 16kx16k observing performance (source type, magnitude, filter, seeing, sky brightness, airmass, atmospheric transmission).
Link: Official Site
Author: A. Rifatto - INAF-OACN
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