A Multi-Channel Speckle Imaging System for the DOT

Abstract

The Dutch Open Telescope (DOT) had its initial observing campaign in September 1999. Although only a simple video system was used, the results demonstrated the excellent high-resolution capabilities of the combination of the open-telescope concept, the DOT optics, the La Palma site, and the speckle masking algorithm used to overcome the remaining image degradation due to the earth's atmosphere. The latter technique was therefore selected as primary DOT observing mode. The DOT data-acquisition system is now being rebuilt into multi- channel imaging optics with fast digital 10-bit cameras and large-volume speckle burst storage. It will simultaneously map the deep photosphere in the G band and the chromosphere in Ca II K and Ha. In addition, trial Doppler imaging in the Ba II 4554 line with a narrow-band (80 mÅ ) Lyot filter from Irkutsk is so promising that usage of this filter is now planned as well.