The sky brightness and transparency in i - band at Dome A , Antarctica

The i-band observing conditions at Dome A on the Antarctic plateau have been investigated using data acquired during 2008 with the Chinese Small Telescope ARray (CSTAR). The sky brightness, atmospheric extinction, cloud coverage and auroral appearance are obtained from these images. The median sky brightness of moonless nights is about 20.46 mag arcsec in the Sloan Digital Sky Survey (SDSS) i band magnitude system, and the median over all brightness in the Antarctic winter is about 19.81 mag arcsec. There were no thick clouds in 2008, and the weather is not so good as anticipated in June and July. We National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, P. R. China; [email protected] Nanjing Institute of Astronomical Optics and Technology, Nanjing 210042, China Purple Mountain Observatory, Nanjing 210008, China School of Physics, University of New South Wales, NSW 2052, Australia Chinese Center for Antarctic Astronomy Current address: Macquarie University & Anglo-Australian Observatory Polar Research Institute of China, Pudong, Shanghai 200136, China Steward Observatory, University of Arizona, Tucson, AZ 85721 Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 Tianjin Normal University, Tianjin 300074, China Department of Astronomy and Astrophysics and Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 Graduate University of Chinese Academy of Sciences, Beijing 100049, P. R. China