Decommissioned instruments

Since 1973 four instruments have been mounted at the Cassegrain focus of the Copernico 1.82m telescope. Currently only AFOSC and Echelle are available. The characteristics of decommissioned instruments are given below.


At the Cassegrain focus an adapter was used with the CCD camera and the filters wheel for direct imaging.

The CCD camera consists of three main parts:

  • the cryostat with the CCD sensor

  • the analog-electronics

  • the control-system.

The control system was located in the Coude' room and is connected to the remaining parts through a 30 m link. The whole system was controlled by the operator either from the Coude' room or from the dome room. Off-set guiding through an intensified TV-camera was possible both at the console in the dome and in the Coude' room. About 30 broad and narrow band filters were available at Ekar which are listed in table. The filters were classified according to their band width (broad or narrow) and to their central wavelength. The last column gives the starting wavelength of the red leak.

Table 1. Johnson and Cousin Filter

Table 2. Gunn Filters

Table 3. Interference Filters


The Boller and Chivens spectrograph was equipped with the "Dioptric Blue Galileo Camera" with a focal length of 188 mm and an off - axis parabola collimator with 90 mm of diameter and a focal length of 810 mm. There is a comparison source, a hollow cathode Fe - Ar lamp, for wavelength calibration. There are five gratings available for the B&C spectrograph with dispersion ranging from 42 A /mm to 339 A/mm. Gratings can be changed, but the spectrograph must be refocussed after every change. Refocussing can take up to 2 hours and it is therefore not recommended during the nights observing. Actually B&C spectrograph is mounted at the Galileo 1.22m telescope (DFA University of Padova).

In the table the available gratings are shown together with their principal characteristics: