First day-time seeing observations at the TÜBITAK National Observatory in Turkey

Abstract

Despite the fact that selecting good solar observatory sites is an important matter, day-time seeing quality of observatory sites in Turkey has not been previously recorded. Therefore, we built a Solar Differential Image Motion Monitor (S-DIMM) for day-time seeing observations at the TÜBITAK National Observatory (TUG) in Turkey which is being tested as a likely site for a future large aperture solar telescope. In this study, we describe the design of TUG S-DIMM instrument and a reduction procedure for its data. First results obtained at 7 m above ground show that the day-time Fried parameters at the TUG site are comparable with those of some solar observatory sites. The best seeing conditions at the TUG site occur between October and December with a median Fried parameter of 6.95 cm in the first three hours of the day. The median Fried parameter calculated from all observations made during our observation period is 4.48 cm. Our observations also reveal that the best day-time Fried parameters are obtained for wind speeds higher than 3 m/s.