Preliminary Results of Atmospheric Extinction Coefficient Measurements at Gaomeigu Observational Station

The measurement of the atmospheric extinction coefficients is one of the important and fundamental works for astronomical observatories. By using the newly-built 2.4 m telescope at Gaomeigu Observational Station of Yunnan Observatory, the calibration works, such as the measurement of the atmospheric extinction coefficient, are carried out and their preliminary results are presented. By observing the Landolt standard stellar fields during April and May 2009, the atmospheric extinction coefficients of five bands UBVRI at two nights are given. In addition, the components which contribute to the atmospheric extinction coefficients of this site are discussed. The measured extinction coefficients are found to be basically consistent with the previous results obtained in the site selection some years ago. And they are also compared with the values of some other well-known observational stations worldwide.