Abstract:
The sky conditions were monitored and duration of photometric and spectroscopic hours determined on 198 nights during the period September 1984 to October 1986. Observations were continued from May till November 1987 and again from June to October 1988, when additionally the temperature and relative humidity values were systematically recorded. Several standard stars were monitored on several nights to determine the extinction coefficients in UBV bands; in addition, sky brightness was measured on eight nights in the months of September and October 1988. The values of sky brightness appear to be marginally higher than at La Palma. The average values of extinction coefficients, determined on 27 nights during 1988 show a general agreement with the earlier values.
