Telescopio 91 cm PDF Stampa E-mail



 Optical configuration
 Mount type
 Main mirror
 diameter  91 cm
   curvature  paraboloid
   focal length
 4.143 m
  focal ratio
 Secondary mirror
 diameter  24 cm
   focal length
 -1.427 m
 Cassegrain focus
 equivalent focal length
 14.275 m
   equivalent focal ratio


 Il telescopio 91 cm è un riflettore con montatura classica Cassergrain. Gli specchi sono stati costruiti da Tinsley (Berkeley, USA). La montatura è del tipo tedesco costruita dalla ditta Marchiori (Roma) su disegno dell'Ing. L. Majorana. In aggiunta al fuoco Cassegrain sono anche disponibili il fuoco primario e newtoniano, il loro uso oggi è assolutamente sconsigliato.  Il telescopio è operativo dal 1965.






Pointing and tracking

A personal computer acts as interface to the observer, and provides commands and information to a microprocessor board that controls the telescope position and the brushless engines. The pointing and tracking speed can be set within large intervals. The telescope operation software Asterix is user friendly, and is described in detail by the automation group.
An intensified TV camera fed by a removable 45o mirror allows the fine pointing and off-set tracking. A focal reducer, with a reduction factor of 3, provides a field of view (FoV) of about 5x5 arcmin on the camera cathode. The limiting magnitude is about V=15.5.
Another intensified camera is connected to the interface box that holds the optical fibers feeding the echelle spectrograph. A beam-splitter brings a 10% fraction of the star light toward this camera, whose FoV is of about 3x3 arcmin.The limiting magnitude is about V=12.5.
Finally, an auxiliary finder of 80 mm aperture and 1 m focal length, equipped with another intensified camera, provides a FoV of about 40x30 arcmin. This telescope is useful for field and object identification.A better description of the TV system can be found here .
Fine tracking corrections can be done automatically by Panoramix, the auto-guiding system purposely implemented. Depending on the focal-plane instrument and the observing mode, the input of Panoramix can be switched from the above mentioned cameras.  





Ultimo aggiornamento Sabato 08 Gennaio 2011 21:27