First day-time seeing observations at the Observatory of University of Zanjan in Iran

Abstract

Recognition of the appropriate locations for ground-based observations of the Sun with high angular resolution depends on the factors such as seeing, meteorological and astronomical parameters. Seeing is one of the most effective parameters that could limit the quality of the observations. Therefore, to have an accurate observation, one needs to have an accurate estimation of this parameter. Using Solar Differential Image Motion Monitor (S-DIMM) method, the day-time seeing parameter is estimated for the first time at Optical Observatory of University of Zanjan, Iran. Because of hard observational conditions, the data collected at a height of 8 meters above the ground between 3rd of July to 18th of October 2018, using an 8 Inch MEAD telescope covered with a two-hole Hartman mask and a 99.99999 % solar glass filter. The results of Fried Parameter at the Observatory of University of Zanjan show a median value of 5.3 cm, with the first, and third quartiles being equal to 8.3 to 3.6 cm, respectively. The best seeing results are obtained between 9:00 to 9:30 a.m., Iran local time. Above the 6% of the measured Fried parameters are obtained to be larger than 10 cm, which seems to be better than the seeing condition at TUBITAK National Observatory, Turkey. The obtained median value of the Fried parameter during the observation period of this study is comparable with the median Fried parameters measured at good solar observatory sites, such as, Big Bear, Haleakala, La Palma, Panguitch Lake, Sacramento Peak, and San Pedro Martir, during July-September. Continuous Day-time seeing observations are needed to make a better comprehensive comparison.

Keywords

• Atmospheric Effects; Site testing; Turbulence; Seeing