Belogradchik Observatory - the Automatic 60 cm Telescope
The Belogradchik Observatory together with the Rozhen National Observatory are both observational stations of the Institute of Astronomy, Bulgarian Academy of Sciences. It is situated in the west part of Balkan Mountain, 180 km from Sofia, near the wide-known stone phenomena to the small town of Belogradchik. The coordinates of the observatory are: E. Long.: +22deg 40.1min; Lat.: +43deg 37.6min. The altitude above the sea level is 630 m. There are approximately 180 clear nights per year there.
Figure 1. View of the Belogradchik Observatory.
The observatory is equipped with a CARL-ZEISS 60 cm Cassegrain reflector with equivalent focal length 7.5 m. A one-channel photon-counting photometer with EMI 9789 QB photomultiplier, attached to the telescope and a set of 6 diaphragms (from 13.8 arcsec = 0.5 mm to 137.5 arcsec = 5 mm) were built at the workshop of the Department of Astronomy in Sofia. The UBV and uvby photometric systems are realized. The respective filters are mounted in a common wheel.
An automatic system using IBM-PC/AT computer and synchronized moving of the dome has been recently built. The automation of the telescope includes: R.A. and D. positioning system up to 6 stellar objects in a field of 6 degrees with accuracy of 5 arcsec each, and automatic moving of the filters; An interface to the computer used for collecting and photometric data storing; A specially created software package "Automatic Photoelectric Reduction" (APR), written in Turbo-Pascal 5.0 for PC/MS-DOS 5.0 system. This software package contains programmes for data reduction in the standard UBV system and visualization of the light curves.
Two types of observations are usually run: estimate of the photoelectric magnitudes of the stellar objects and patrol observations. As far as the minimal possible integration time is 0.1 sec and the maximal one is not limited, the automatic 60 cm telescope of the Belogradchik Observatory is suitable for observations of stellar objects, asteroides, galaxies and for searching and detecting of very rapid brightness variations. The automatic 60 cm telescope at the Belogradchik Observatory is suitable for searching and detecting of very rapid brightness variations and for observations of stellar objects, asteroids and galaxies up to V = 13.5 mag.
Figure 2. The automatic 60-cm telescope system.
More detail information about the telescope and the automatic system one can find in:
Antov, A., Konstantinova-Antova, R., 1995, "Robotic observatories", Proc. Kilkenny Workshop, 1992, Kilkenny, Ireland, Praxis Publishing, ed. M.F. Bode, p. 69.