Solar double H-alpha and white light telescope
Acquisition system & data storage
The double solar telescope at Hvar Observatory was built in 1972 based on an agreement between the Faculty of Geodesy of the University of Zagreb and the Astronomical Institute of the Czechoslovak Academy of Sciences. Since that time, continuous development on the telescope and its acquisition system followed the rapid evolution of the electronics and computers. In 1997 the original photographic material acquisition system was replaced by a video-recording system, and then again in 2004 with 1MPix 10-bit CCD camera. In 2010, the fourth generation of acquisition hardware and software was installed, together with some improvements on the optical telescope design. As a result of tight collaboration between the Faculty of Geodesy and the Institute of Physics (IGAM) of the University of Graz, Hvar Observatory implemented identical acquisition system as the Kanzelhöhe Solar Observatory. The aim is to complement Kanzelhöhe full-disc images by Hvar active-region high-resolution images.
It provides a valuable tool to study rapid changes of chromospheric and photospheric features in great detail. The telescope consists of two Carl Zeiss refractors (photosphere d=217mm, chromosphere d=130mm) mounted as one unit on a German parallax mounting. Using a field of view of about 7 and 11 arcmin, its aim is to produce high resolution images of active regions on the Sun. New Pullnix TM-4200GE 12-bit CCD cameras allow time series with a cadence up to 30 images per minute.