Over the last 40 years, a small group of Spanish amateurs has been systematically measuring visual double stars. They are currently preparing to publish all the measurements made between 1970 and 2001 - some 10,000 in all. This massive work was presented in October, 2000 at the annual meeting of the Astronomical Society of France's Double Star Commission, held in Castelldefels, near Barcelona, Spain. An Internet version will soon be available.

The first measurement catalogue entirely produced in Spain by an amateur was that by José-Luis Comellas (a lecturer in Modern History at the University of Sevilla - see Figure 20.10). The first, published in 1973 (Catálogo de Estrellas Dobles Visuales 1973.0), contained measurements of 1200 double stars, using a simple micrometer and a 75-mm aperture Polarex-Unitron refractor. Twelve years later, the same author

published a second catalogue (Catálogo de Estrellas Dobles Visuales 1980.0) that included 5104 doubles within reach of his new 102 mm aperture Polarex-Unitron refractor, of which he personally measured over 3500.

Since 1985 other observers have maintained the continuity of Comellas' work. From 1976, Tófol Tobal regularly collaborated with him, and in the mid-1980s he built a small observatory equipped with a 102-mm Polarex Unitron refractor and a filar micrometer, allowing him to start a systematic revision and update of the 1980.0 catalogue. In 1991, in conjunction with other colleagues, Mr Tobal coordinated the measurements sent by individual observers and began to publish a circular (RHO: Circular de Estrellas Dobles Visuales) for internal use, in order to coordinate the work and to publicise the results. Recent acquisition of new precision micrometers, double image Lyot-Camichel-like, and CCD devices have been made, and between 1992 and 2000 more than 5000 new observations and measurements has been collected, provided by amateurs throughout Spain.

In 1991 the Garraf Astronomical Observatory (OAG) was founded and on the original site (1992-1998) it had a

Figure 20.11. The observatory in the Garraf National Park, near Barcelona.

3.5-metre diameter dome with a 260-mm aperture Newtonian. A new observatory has been constructed (Figure 20.11); using public and private investment and is located 30 km south of Barcelona, inside the Garraf Natural Park and was opened in November 2001. It has a new 3.5-metre dome and a 30-cm Newtonian-Cassegrain f/3.5 and f/12 telescope fitted with a CCD camera and a Lyot double-image micrometer.

Figure 20.11. The observatory in the Garraf National Park, near Barcelona.

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