Facilities and Services

Buildings

The refurbishment of the main building of the Osservatorio Astrofisico was completed. It was financed by the Università degli Studi di Catania, which is the owner of the building, and by the Observatory. The plan and the direction of the works were under the responsibility of the deputed Office of the University Technical Support Service. The Technical Support Office of the Observatory has been also deeply involved during all the phases of the works to warrant a proper consideration of all the specific requirements for the disactivation and re-activation of the installations and plants as well as for moving around the offices and various facilities from the working areas.

A new high-vacuum facility has been planned for mirror allumination at the mountain station M. G. Fracastoro and required permissions have been granted by the deputed public authorities. A public announcement to find and select the prime contractor will be issued at the beginning of 2003.

The plan for the re-structuring of the building housing the automated telescopes at the M. G. Fracastoro station was approved by the deputed public authorities and by the Parco dell'Etna who recommended the implementation of a scheme considting of three folding domes in order to minimize the environmental impact.

The main characterstics of the three domes were specified in order to allow a fully automated operation of the telescopes and the German firm Halfmann Teleskopetechnik GmbH of Amburg was informally contacted for further advice. They built similar dome structures for ESO at the observatory on the top of Mt. Paranal. We plan to host in the new building also a small telescope dedicated to educational and outreach activities in addition to the automated telescopes.

The roof of the main building at the M. G. Fracastoro mountain station was damaged by the snow and ice during winter 2001-2002. Having been built more than thirty years ago, it requires now an extra-ordinary maintainance work for which a specific plan has been already prepared by the Genio civile.

Training and courses attended by the staff members

A specific training activity was devoted to the staff on duty in order to update and increase their command of the mostly used software systems and packages. Specifically, an IDL advanced course was organized for the scientific staff and a course for advanced users of LINUX mainly for the technical and library staff. Some specific courses covering catalogation and searching softwares and the author's right in scientific publication were attended by the librarians. All the courses and training activities were also open to interested people belonging to the research and teaching staff of the University as well as to PhD students. The detailed list is as follows:

• Banche dati e ricerche bibliografiche AIB Sicilia: Catania, 6 Marzo 2002
• Diritto d'autore- AIB Sicilia: Catania 19-20 Giugno 2002
• Training Catalogazione MILLENNIUM CBD Universita CT: Catania 1-2 Ottobre 2002
• La nuova disciplina del sistema pensionistico. Presentazione ed utilizzo applicativo Pensioni (S7) a seguito convenzione INAF-INPDAP Roma 8-12 Aprile
• Scuola Nazionale di Tecnologie Astronomiche - Napoli 23 28 Settembre 2002
• Corso IDL avanzato tenuto presso l' OACt da un responsabile della RSI Italia
• Corso LINUX utente avanzato MFH: Catania 2-4 Dicembre 2002
• Corso Xiling, Dublin 2-20 december 2002
• Corso su bilancio di cassa con programma CIA 1-3 December 2002, Cineca, Bologna

Acquisition of new instrumentation and facilities

The enhancement and the renewal of the scientific facilities have gone on in 2002 according to the annual programme. Moreover, using the saving on expenses obtained in the previous balances, it has been possible to get new facilities. The most important ones acquired in the course of 2001 are:

• Upgrade of the ion implanter of the LASP, made by the firm Danfysik;
• a new automated photometric telescope (APT80/2): the mechanics and optics have been completed by the firm Marcon;
• a linear lathe made by Mexim to be installed in the new mechanical workshop;
• a criogenic system by Cryotiger for the CCD camera of the REOSC spectrograph;
• a new vacuum dry pump by Triscroll;
• a Shack-Hartmann wave-front analyzer for the alignment of telescope mirrors;
• a new CCD detector for the Raman spectrograph;
• a CCD detector (EEV 05-30) for solar observations;
• a CCD detector (EEV 42-40) for the CCD camera of the APT80/2

Library

Scientific supervisor:	R. Ventura
Staff:	A. Mangano, M. Calì, G. Caripoli, D. Domina, D. Recupero,
	G. Santagati.

 

The library collection of Catania Astrophysical Observatory presently includes 10303 volumes, 126 journal titles, 234 antique (see Fig. 4.1 and 4.2) volumes and a number of audio-video material. The library content is mainly specialized for Astronomy and Astrophysics, but two significant sections are also devoted to General Physics and Mathematics. Moreover, a special section, dedicated to education is continuously updated with cd-roms and video-tapes. The library is open to astronomers, technicians and staff of the Observatory and to teachers belonging to the Departments of the Catania University as well as to researchers and University students of several institutions and faculties, and to all interested visitors (by permission). Opening hours: from Monday to Saturday, from 8:15 to 13:45 and on Monday, Wednesday and Thursday from 14:30 to 17:30. Services: Loan; interlibrary-loan; document delivery service.

Figure 4.1: Library historical section, Secchi (1875): A solar spot drawing taken from ``Le soleil: premiere partie'' by Angelo Secchi, Deuxième édition, revue et augmentée, Imprimerie de Gauthier-Villars, Paris 1875.

Figure 4.2: Library historical section, Tacchini (1888): A solar eclipse drawing taken from ``Eclissi totali di sole'' by Pietro Tacchini, Tipografia Eredi Botta, Rome 1888.

Due to the refurbishment work inside the Observatory buiding, the reading room was unaccessible and some reading space was provided inside the main library hall. The routine maintanance activity were reduced to essential and urgent tasks in consideration of the limited space available.

Acquisitions and inventory (G. Caripoli, D. Domina, M. Calí). The saving imposed on the Observatory expenses limited the funds avalaible for the library. Therefore a total amount of 73.000 euros was spent during 2002 to buy books and journal subscriptions. The reduction of the fundings implied a remarkable decrease in the number of renewed subscriptions for the year 2003. The selection of the renewed subscriptions was made by taking into account the indication of the research and technical staff as well as the availability of the journals through other observatories or institutes belonging to the national library network Archivio Collettivo Nazionale Periodici (ANCP). The on-line services provided by the Centro Biblioteche e Documentazione of the University of Catania granted access to several on-line journals and further helped to reduce the cost of subscriptions. In general, the reduction of costs for every single acquisition was also made possible by the comparison of on-line offers and by the services offered by the library consortiums (ESO, CNR-Bologna, CILEA; CBD- Catania, INAF) which provided free journals in a mutual exchange regime.

Cataloguing (D. Domina, A. Mangano). New books acquired in 2002 (about 90) have been catalogued according to descriptive and semantic rules, with the UNIBIBLIO software. The relative bibliographic control has been made when the records have been exported to built the web catalogue. The semantic cataloguing has been made using an Italian Subject Index (edited in 1999) which refers to that of the Library of Congress and to the IAU Thesaurus. The new software MILLENNIUM - a new integrated web-based cataloguing software provided by the University of Catania - has been tested and used for some limited applications. Journals catalogue (L. Santagati, A. Mangano). The update of the journals list has been performed following the on-line procedure of the Archivio Collettivo Nazionale Periodici (ACNP), adopted by the library. In 2002 the on-line service of document delivery has increased (more than 120 articles required both by the Italian Observatories and other Institutes partecipating to the ACNP consortium and other inter-library exchange organizations). This retrieving work required a significant increase of dedicated time with respect to year 2001.

Historical Archive and Catalogue (D. Recupero and A. Mangano). In the framework of the national project Specola 2000 which gathers all the Italian Observatories with the aim of developing and making the historical collections accessible, the Sovraintendenza Archivistica per la Sicilia committed the inventory of the historical archive to an external collaborator. The bibliographic part and the correspondence was previously sorted by the librarians. The joint work of the collaborator and of the Observatory staff librarians led during 2002 to the completion of the inventory of the historical archive for the period 1865-1954. It is presently accessible in printed form and contains seven series of documents of great importance for the history of Catania Observatory. The series of letters has already been requested for consultation by various users, both internal and external.

Scientific secretariat and Preprints (D. Recupero and L. Santagati). Thirty-eight preprints have been printed and distributed to 47 Italian and foreign Astronomical Institutes and Observatories. All the preprints were made accessible also through the web site of the Observatory. Several papers have been linguistically reviewed. The organisation of the Third Meeting on the Italian Solar Research held in Vulcano in October 2002 was managed. The proceedings of the international meeting "Asteroids 20001. From Piazzi to the 3rd Millennium" were also edited for the Memorie SAIt.

Loan, reference service, electronic information service (D. Domina, A. Mangano, D. Recupero, L. Santagati, G. Caripoli). The reference service for students and researchers consists in the search in the local catalogues, both printed and on-line, and other external catalogues using internet facilities. The intense collaboration between the libraries of the other Italian Observatories has enhanced thanks to the CUBAI (Catalogo Unico Biblioteche Astronomiche Italiane) and ACNP Astronomico projects. Other collaborative links has been established (CIBD Centro di Coordinamento delle Biblioteche dell'Universitá di Catania and other foreign institutions) in the framework of a more and more intense inter-library cooperation.

Activity in coordination with INAF. During the year 2002, frequent exchanges and meeting were held among the librarians of the Italian observatories, coordinated within INAF. The library staff of Catania Observatory contributed to several significant aspects, assisted also by an expert in computer science for the development and implementation of new software for a new national astronomical library service. The development of a National Library System for INAF has been proposed in order to optimize the available resourches and made them fully available to the research community. A detailed report on the library of Catania Observatory was prepared as a first step for contributing to this project according to the guidelines specified the deputed INAF working group.

Computing Center and local network

Supervisor:	P. Massimino
Staff:	A. Costa, C. Lo Presti, A. Giuffrida

 

Catania site: The computing center consists of central machines and distributed workstations, running various operating systems:

• Central machines (computing servers):
  • SUN Sparc 20 (UNIX) Server and Sun cluster
  • Compaq DS10 (Open VMS)
  • SG Origin 200 with two processors (UNIX)
  • LINUX Cluster based on 5 PCs AMD 1.4 GHz
  • IBM 9076-550 SP3 with 24 parallel processors
• Network server:
  • PC Linux Suse 7.2 (astrct: DNS, SSH ..., FTP, WEB and the solar image archives)
  • PC MS-WindowsNT (netserver, interactive Web services for astronomy and library)
  • a LAN consisting of 75 personal computers and workstations for the research staff, technicians and administration staff.
  • four laser printers

During 2002 the implementation and reconfiguration of the components which must guarantee the security of information systems have been continued. New facilities have been implemented. The problem of security has been among the main issues of this year.

The principal specific activities can be summarized as follows:

• The new firewall Sonicwall Pro 200, supplied with the "High Availability" software, was installed and configured. It allows a detailed analysis, both through graphics and tables, of all the networked activities generated in the Observatory's LAN and of those generated in the external WAN.
• A new control system to prevent spamming activities was implemented on the SMTP server. It consists of two components, MailScanner and SpamAssassin, which seek for viruses attached to e-mail messages and for spammed messagges, respectively. In this way, the risk of propagation of viruses through e-mail and of spamming attacks is largely reduced.
• The computing resources available on the Linux cluster were updated and upgraded also by including new nodes. One node is exclusively dedicated to mass memory sharing and to management of the printer queues.
• The security level of the remote accesses operated through the new PPP(ISP) server was increased. In its present configuration, it allows several users to access simultaneously our server by means of four telephone analogical lines operated by the OACt PBX (switchboard).

OA Catania Web site: The observatory web page is continuously updated. The new implemented resources includes: Minor Planet Electronic Circulars (MPEC) and IAU Circulars, the access to which is restricted to internal users connecting through the Observatory's LAN. The on-line catalogue of the Observatory's library has been continuously updated and made available to internal and external internet users. Moreover, the electronic versions of our preprints were made fully accessible through internet in collaboration with the library and scientific secretariat staff. The new server www.astrocomp.it was configured for use in the framework of the AstroGrid project.
Solar images on the Web: The images of the Sun acquired during 2002 at Catania Observatory were put on the Web and catalogued in "web access" mode, thus updating our solar image web archive. All the images daily collected on the web page are stored in the archive and are freely accessible.

M.G. Fracastoro station (Serra la nave, Etna): Starting from a feasibility study and the positive tests performed during 2001, a detailed technical plan was issued for a wireless connection at 2.4 GHz between the Catania site and the M. G. Fracastoro mountain station. The connection between the lodge and the nearby ENEL tower on which the antenna at the M. G. Fracastoro site is going to be located, will be made by means of optical fiber cabling. The necessary authorizations were finally obtained by Parco dell'Etna for the underground cabling, by Enel for the installation of the antenna, by the Ministero delle Telecomunicazioni for the frequency allocation, respectively. The firm Software and Network Consulting is in charge of the implementation of the plan.

Training activities and partecipation to scientific meetings. Fifteen members of the staff attended the course on Linux held by MHP at the Catania section of INFN. P. Massimino and A. Costa attended the IV Garr meeting at Bologna and presented a communication on the new wireless connection between the Catania site and the M. G. Fracastoro mountain station. The first meeting of the system managers of the Italian Observatories belonging to INAF was held in Florence and was attended by P. Massimino on behalf of Catania Observatory. P. Massimino and A. Costa are involved in the project DataGrid, in collaboration with INFN. Moreover, P. Massimino is involved in a project for the scanning and digitization of old photographic plates belonging to the collection of Catania Observatory.

Opto-mechanical workshop and telescopes' automation

INAF staff:	G. Carbonaro, G. Gentile, M.P. Puleo, E. Martinetti,
	M. Miraglia, S. Sardone, P. Bruno
External collaborator:	S. Massaro

 

Telescope automation

91-cm Cassegrain telescope: The new software "Asterix 2000", installed and commissioned in 2001 confirmed its stability and operation effectiveness. Its main utilities include:

• on-line catalogue of stars with magnitudes $>$2, used for the calibration of the telescope
• on-line NGC, IC, UGC, SAO, Messier and GCVS catalogues
• view of the selected field through the images of the DDS catalogue accessible via internet
• on-line processing of the image acquired from the DSS catalogue
• calculation of the ephemeredes of the solar system objects

The software converting the telescope coordinates into the azimuthal system will allow to interface the control system to the electronic encoder providing the position of the dome. Therefore, it will be easier to perform a complete automation of the telescope. The cloche has been modified to allow the interface with the tracking electronic system. A tracking software has been developed within the Lab-view environment, using its graphic libraries. The image acquisition card has been replaced with an updated one which performs the processing through a 10 bit A/D converter. The effectiveness of this system proved to be good and it was used for most of the year. The determination of the centroid of the reference star and the tracking of the telescope are made on a single digitized frame acquired by the intensified camera. The current accuracy of the tracking is about 0.5 arcsec with corrections typically applied on timescales of 5 s. The accuracy in the tracking may be improved by using more frames, but a limit is set by the telescope mounting mechanics.
 
The optical quality of the imagine at the Cassegrain focus was tested by means of a Schack-Hartmann wavefront analyser. This revealed some anomalies in the mechanical supports of the primary mirror and a variable misalignment of the secondary mirror due to the flexions of the telescope tube, which were already qualitatively known from previous tests. Therefore, a feasibility study was undertaken to desing a moveable support for the secondary mirror and the implementation of a Schack-Hartmann wavefron analyzer to improve the quality of the image. The best seeing measured at the M. G. Fracastoro station was of the order of 1 arcsec, hence the improvement of the telescope optical quality according to the above plan is highly recommendable also in consideration of the foreseen application of a photometric CCD camera and of the use of an optical fiber of 100 micron for the spectrograph.
 
61-cm Schmidt telescope: The project of the mechanical revision has been critically re-examined and updated before starting the operative phase. In particular, a series of tests showed that it is not possible to use a system based on a double pinion and a brake for moving the telescope in declination without angular clearance. Moreover, the double pinion system with an electric pre-loading would require a cooling system of the engines too complicated for application to a 61-cm telescope. Therefore, the whole system was re-designed considering the user of a brushless torque engine manifactured by ETEL which does not need braking and cooling systems and is capable of operate under a load unbalance up to 100 kg. The design phase was completed and the engine and the encoder have been commissioned. The controller is similar to that of the Galil system and is thus fully compatible with the control software Asterix, the standard operation software managing all our telescopes.
 
APT-80/1: A fault occurred in the controller was impossible to be repaired because the necessary electronic components are out-of-stock. A re-design of the whole operation and acquisition systems is presently carried on, in order to make the telescope operable with a new control hardware and software no more limited by the MS-DOS operating system on which the previous one was based.
 
APT-80/2: The manufacturer Marcon has completed the mechanics and the mirrors [ (figure 3)]. The motion of the telescope, based on brushless engines and on the Galil controller has been implemented by the staff, following the standard procedure applied for every telescope at the Observatory. The pointing and tracking operations have been successfully tested at Marcon by the Asterix 2000 software, thus confirming its reliability and portability. Pointing and repeatibility accuracy, tested with a laser beam, matches the constraints requested to the manufacturer. The requirements of the domes, whose aperture must be compatible with the automatic movement of the telescopes, have been set and the Halfmann Teleskopetechnik GmbH in Hamburg , which will realize the cover with folding material, has been contacted. This kind of cover has been already installed at ESO at Mt.Paranal. The building will also host a telescope for educational activities. The required authorizations have been obtained by Parco dell'Etna.

Opto-mechanical laboratory

Aluminization: The primary mirror of the 91-cm telescope was re-aluminized, using a new procedure for evaporating the metal. The reflectivity gain was remarkable in comparison to the past and a further improvement was obtained thanks to the re-configuration and alignment of the optical system.
 
Spectro-polarimetric module: The spectro-polarimetric module for the REOSC echelle spectrograph mounted at the 91-cm telescope has been successfully tested and the precision of positioning and alignment of the polarizing plate have been checked. An analogue module, which makes use of super achromatic plate, realized for the high resolution spectrograph (SARG) has been installed at the Telescopio Nazionale Galileo. Since the first tests we could notice the high quality standards of the system which in agreement with the characteristics required, has an efficiency of 92 % and 85 % for the linear and circular polarization respectively.
 
New off-set guider: The project of the new offset to be mounted at the 91 cm telescope has been completed, the support structure has been built and the software for the movement of the probe mirror has been installed. It is based on a programmable high-precision controller (10 microns in the positioning accuracy). The system allows to put the probe mirror in the central position for pointing as well as in four side position for the off-set guidance.
 
Focal reducer and CCD camera: A focal reducer for the CCD camera was built with two filter wheels for UBVRI filters. The CCD camera, with a newly conceived Peltier cooling system, is under construction by the firm Hitech under the supervision of the detector research group of the Observatory. The camera uses a 1024x1024 CCD with 24 micron pixels; it will have a 10 arcmin field of view and will reach a magnitude 18 with S/N=100 in 10 min.
 
Technical installations: The LAN network has been installed in the new building of the Catania Observatory: new access points have been activated in all offices and working desks for PhD students. The same network has been installed in the two offices at M.G. Fracastoro Observatory on Mt. Etna, and the connection with the dome of the 61-cm telescope has been activated.

CCD image acquisition

Supervisor:	G. Bonanno
Research staff:	R. Cosentino, S. Scuderi
Technical staff:	M. Belluso, P. Bruno, A. Calì, M.C. Timpanaro

 

The activity of the image acquisition devices is managed by the detector staff, who performs the maintenance and implementation of new cameras and control systems. The activity carried out in 2002 consists in the following:

Solar CCD Camera: The old CCD camera implemented ten years ago is still operative with the acquisition system COLD-WIN with image storage in FITS format, under the continuous supervision and technical maintainance by the detector group staff. Moreover, our staff completed the installation of a mechanical device for positioning and controlling the focus of the lens on the solar spar, adopting a standard device control system.

Imaging CCD camera for the 61-cm telescope: A new camera, cooled by Peltier effect cell, was designed and manufactured by the group. The mechanical interface with the filter wheel was designed by the group and built by to an external manufacturer (TMA). Its control system is based on a standard set up built by the staff. The system, including the controller and the kodak CCD, is under final testing.

Imaging CCD camera for the 91-cm telescope: The staff has designed and manufactured a prototype of a new camera for the 91-cm telescope coupled to the focus reducer. This camera will be cooled by a three stages Peltier effect cell able to reach temperatures of $-70^{\circ}$ C. The prototype is under testing as far as the vacuum and the limit temperature are concerned. The final design has been commited to the firm Hitech of Catania under the supervision of the group.

Photometric data acquisition and reduction

Supervisor:	E. Marilli
Technical Staff:	V. Greco, C. Lo Presti, P. Massimino

 

The photometric laboratory deals with:

• The setup and testing of the single channel photometer for the acquisition of photometric data at the focal plane of the 91-cm telescope at Serra La Nave.
• The development of hardware and software for acquisition, reduction and storage of data.

The large-band photometry with U B V filters and with interferential filters u v b y H$_W$ H$_N$ g1 g2 (Stromgren photometric system) is performed by the photon-counting single channel photometer cooled by a Peltier effect system at about $-15^{\circ}$ C and equipped with a photometric head characterized by low dark current (about 1cts/sec at $-15^{\circ}$ C). The filters are mounted on the filter wheels operated through a step engine, managed by the acquisition software OBELIX. The optimization of times to move from one filter to the next one has been carried out. This system activates two different acquisition modes: a standard acquisition, which allows observations with one or more filters with maximum time resolution between two measures of 0.2 s, and a fast acquisition mode with a maximum time resolution with one filter up to 0.01 s, implemented in the last version of OBELIX written in Visual Basic (Win Obelix). Besides the photometric acquisition program OBELIX, two new packages have been implemented in 2002 which allows the FFT of long time series to seek periodicities. It proved to be very useful in the search for new pulsating subdwarf, specifically those belonging to the sdB subgroup.

The group goes on maintaining and updating the software "PHOT" for the data reduction, which allows the rapid reduction of data in magnitude differential, standard UBV and Stromgren system. The package runs in DOS and VMS environment. It is characterized by a high degree of flexibility to adapt to the different requirements of observation and data reduction.

The group has continued the development a new software which, by using the WEB and the computing resources accessible via internet, performs:

• automatic cataloguing of acquired photometric data
• photometric archive consultation
• input of new photometric data
• automatic processing of photometric data with display of graphics and tables

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

Supervisor:	A. Frasca
Technical staff:	G. Carbonaro, A. Di Stefano, A. Miccichè, M. Miraglia,
	G. Occhipinti, M. G. Puleo
Maintenance staff:	G. Corsaro, C. Scuderi, M. R. Caruso

 
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 91-cm Cassegrain reflector [figure ]
• The 61/41-cm Schmidt-Cassegrain Universal Telescope [figure]
• The automatic Ritchey-Chretien photometric telescope (APT/1-80cm)
• A 30-cm Cassegrain reflector, hosted in the APT/1-80cm's building.

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.

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

• REOSC Echelle spectrograph ($f/15$ collimator and CANON camera f=300 mm, $f/2.8$) with the possibility of observing in single dispersion (resolution of 0.9 Å/pxl) or cross dispersion (resolution of 0.15 Å/pxl). The spectrograph is connected to the telescope by means of an optical fibre and during 2000 it has been equipped with a polarimetric module for the measurement of the linear and circular polarization, allowing the determination of the four Stokes parameters. The acquisition system consists of a CCD camera (1024x1024, with 24 micron pixels), managed by the same software developed for the TNG cameras.
• Single head photometer for UBV photometry, ubvy-H$\gamma$ and cometary bands (IHW). The photometer can perform photometry with maximum time resolution of 0.1 and 0.5 s, using a single filter or different filters sequentially inserted, respectively.
• Double-channel photometer URSULA for simultaneous UBV photometry of two near objects.
• Near IR photometer (JHKLM bands) with InSb sensor, cooled by liquid nitrogen, which is normally used up to K band (2.2 micron).
• CCD Camera. Some tests have been carried out with the controller developed for the TNG telescope and a focal reducer with a field of view of about $10^{\prime}$ is under construction as above explained.

 
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 photometer contains standard UBV filters mounted on a rapidly rotating wheel (0.1 Hz), which performs quasi-simultaneous measurements in the three filters (maximum time resolution of 1 sec) and is particularly suitable for the study of rapidly evolving events, such as stellar flares. 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. The observational efficiency (duty-cycle), over a 10-year operation period, has been estimated to be of about 70%, while the traditional telescopes seldom get 30-40%. The system is completely automated, including the opening and closing of the sliding roofs of the rectangular block ($4\times 8$ m) hosting it. The opening command of the roof is activated after a meteorological test is passed, on the basis of fixed meteorological limits (absence of rain, fog, strong wind and so on).
 
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 telescope is presently under revision.

The statistics relative to the use of the telescopes nights/year are listed in the following table:

Table 4.1: Telescopes activity

	Cassegrain 91-cm				APT/1 80-cm
	1999	2000	2001	2002	1999	2000	2001	2002
Nightly use $> 50$%	167	156	156	161	157	183	100	89
Nightly use $<50$%	32	34	38	29	70	38	41	18
Maintenance and testing	36	35$^{a}$	26	31	10	6	15	3
Not used (meteo)	112	115	135$^{b}$	138	117	124	196$^{b}$	199$^{c}$
Not used (failure)	18	26	10	6	11	15	13	66
Notes: (a) Including the period of inactivity (60 days) spent for the aluminization
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

Research programs: During 2002 the following research programs have been carried out at the M. G. Fracastoro station:

• Systematic long-term study of stellar activity by means of wide-band photometry (APT 80)
• Structure of the chromosphere and its evolution for variable stars belonging to the RS CVn and T Tauri groups by means of spectroscopic monitoring of the H$\alpha$ line;
• Correlation between photospheric spots and chromospheric faculae in RS CVn binaries by simultaneous optical photometry and spectroscopy
• Measurement of the temperature variation associated with stellar spots
• Characterization of the promary targer of the space mission COROT
• Rotation of young stellar objects (PMS and T Tauri)
• Measurements of chemical abundances and magnetic fields in CP and Ap stars
• Photometric studies of the minor bodies of the Solar System and of the mutual events of Jupiter's and Saturn's satellites
• Partecipation to coordinated multi-site campaign for the observation of Blazars and ToO
• Mass loss determination in variable star of the P Cygni class
• Spectroscopic studies of planetary nebulae
• Pulsations of sdB stars.

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:  [11], [12], [15], [18], [20], [26],  [28], [30], [33], [34], [35], [36],  [38], [39], [42], [46], [56], [59],  [77], [80], [105], [106], [110], [118],  [135], [137].
 
 

Solar observation facilities

Supervisors:	D. Spadaro, F. Zuccarello
Technical staff:	S. Billotta (contractor), E. Catinoto, G. Sapienza (until April 1st,
	2002), S. Sciuto

 
Equatorial spar. The equatorial spar (see Fig. 4.3) consists of 6 optical benches, three of which are devoted to the daily observing program:

• a bench for the white light observations, sunspot shape and sunspot group drawing;
• a bench for H$\alpha$ observations, chromosphere and photosphere with Zeiss filter (CCD camera);
• a bench for H$\alpha$ visual observations, Halle filter.

Figure 4.3: The equatorial spar.

The data acquired in the framework of this program deal with: groups of sunspots, faculae, quiescent and active prominences on the disk and at the limb, flares (see Fig. 4.4). During 2002 the total number of useful observing days has been 305. The standard sequence of observations consists of:

• one image every 15 min at the center of the H$\alpha$ line (chromosphere);
• one image every 15 min in the H$\alpha$ line wing ($+5$Å, photosphere);
• rapid sequences of images during flares or eruptive prominences.

Figure 4.4: An H$\alpha$ a image of the Sun taken with the Zeiss filter.

The works and improvement of services in 2002 include:

• Adjustments and enhancement of performances of the CCD camera (carried out by the detector laboratory);
• Duplication of the commands to manage telescope control from the room below the dome (carried out by the staff of the laboratory for telescope automation);
• Installation of a movable lens holder for the focusing and the collimation of various instruments (provided by the manufacturer TMA);
• Installation of a second movable lens holder for the focusing and the collimation of the bench for H$_{\alpha}$ visual observations, equipped by a Halle filter;
• Installation of a mechanical adjustable support for the Halle filter;
• Installation of a TV camera enabling the remote pointing of the Sun (carried out by the staff of the laboratory for telescope automation);
• Recording of solar images using the standard international FITS format (carried out by the staff of the Detector laboratory);
• Implementation of a new procedures for data archiving (carried out by P. Massimino);
• Implementation of IDL routines for a preliminary data analysis.

Catania Observatory makes available solar observations also through its web site. It shows links to several international research projects and collaborations to which it actively contributes. Notably, owing to the important improvements carried out in 2001 and 2002, on February 26, 2002, Catania Astrophysical Observatory joined the Global High-Resolution H$\alpha$ Network, operated by the Big Bear Solar Observatory (California, USA), that collects and records chromospheric data obtained by various international observatories, continuously monitoring activity phenomena occurring in the solar chromosphere. This network aims to provide the solar international community with high quality data and to carry on specific researches relevant to the study of filaments, prominences and flares.

Solar observations carried out in Catania also support the activities of the French-Italian solar telescope THEMIS (Tenerife, Canary Islands). H$\alpha$ full disc images hourly collected are put on the web page of Catania Observatory, in order to help in the selection of solar regions to observe by THEMIS (whose instantaneous field of view is smaller than 1 arcmin $\times$ 1 arcmin), also taking into account the longitude difference between Canary Islands and Catania.