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The "Mario G. Fracastoro" station on Mt. Etna

Supervisor: A. Frasca
Technical staff: P. Bruno, G. Carbonaro, A. Di Stefano, A. Miccichè,
  M. Miraglia, G. Occhipinti
Maintenance staff: R. Caruso, G. Corsaro, C. Scuderi
The observing station of Catania Astrophysical Observatory is located at Serra La Nave (SLN), on Mt. Etna, at an altitude of about 1700 m a.s.l. It has been dedicated to Professor Mario G. Fracastoro, who promoted its building during the period of his directorship (1954-1967). This site is about 40 km far from Catania and 20 Km from Nicolosi, the nearest village. Four telescopes are installed in three different domes: The 30-cm telescope is used for educational purposes and outreach activities, e.g., student training and visitors' visual observations. Two additional buildings are used as guardian and guest house, respectively. Moreover, the latter building hosts the mechanical and electronic laboratories for instrumentation maintenance.
The 91-cm Cassegrain reflector mechanical part was manufactured by Marchiori and the optics by Tinsley. It has been operating since 1965. The optics have a classic design. They allow the use of the telescope at its prime focus and at the newtonian focus, with a relative aperture f/4.68, or in a Cassegrain configuration having a f/15 relative aperture. The pointing and tracking system, originally operated by the observer and equipped with fixed frequency engines, has been replaced with brushless engines and digitized reading of coordinates. A Pentium PC with Asterix 2000 - a software specifically developed by our technical staff - drives the telescope in semi-automatic mode.

Figure 3.5: The 91-cm Cassegrain reflector with fibre feed interface

The 91-cm telescope is usually used with the Cassegrain configuration, with the following instruments:

The $61/41$ cm Universal Schmidt-Cassegrain telescope, built by "Meccanica Sarti di Bologna" (1966) is completely manually operated. The Schmidt configuration has a relative aperture of $f/3.5$ and a field of view of $4.2\times 4.2$ degrees in the photographic mode. It is equipped with a secondary mirror which allows a quasi-Cassegrain focus, with a nearly null field of view, used only for photoelectric photometry. The telescope is presently being restored in order to implement an automatic control of the pointing and tracking system, also for objects with large proper motion. It will be equipped with a CCD camera for the monitoring of Near Earth Orbit (NEO) asteroids in the framework of the ITANET project.

The APT/1-80cm (Automated Photoelectric Telescope) built by AutoScope Co. (Tucson AZ, USA) was installed at the end of 1991. The optical configuration is a Ritchey-Chretien type with absolute aperture of 80 cm and equivalent focal of about 6 m. Both the telescope and the photometer (UBV) are automatically operated by a PC-AT/386.
Due to the reconstruction of the building, the telescope have been taken out and at the same time the hardware/software of the pointing/traking system vent on revision.

The telescopes of the M.G. Fracastoro stellar station operate for about 350 nights in a year. Six technicians in turn guarantee the night technical assistance. The 91-cm and the APT/1-80 cm are fully time allocated, while the 61-cm Schmidt and the APT71 telescope are presently under revision.

The statistics relative to the use of the telescopes nights/year are listed in Table 3.7:

Table 3.1: Telescopes activities
  Cassegrain 91-cm APT/1 80-cm
  2001 2002 2003 2004 1999 2000 2001 2002
Nightly use $> 50$% 156 161 164 169 157 183 100 89
Nightly use $< 50$% 38 29 20 62 70 38 41 18
Maintenance and testing 26 31 8 15 10 6 15 3
Not used (meteo) 135$^{b}$ 138 110 104 117 124 196$^{b}$ 199$^{c}$
Not used (failure) 10 6 63$^{d}$ 15$^{e}$ 11 15 13 66
of the mirrors and the revision of the bearing of the primary mirror
(b) Including the time spent for the aluminization of the primary mirror (20 g days)
(c) Including 30 nights of inactivity due to the eruption of Mt. Etna
(d) Including 59 nights of inactivity due to lack of funds
(d) Including 15 nights of inactivity due to lack of funds

Research programs: During 2004 the following research programs have been carried out at the M. G. Fracastoro station:

The papers published in internationally referred journal and the invited contribution totally or partially based on observations made at the M. G. Fracastoro station are: (), () (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), ().


next up previous contents index
Next: Out-reach and Education Up: Facilities and Services Previous: Solar observation facilities   Contents   Index
Innocenza Busa' 2005-11-14