Astrophysics Moon night sky brightness simulation for the Xinglong station

Abstract Using a sky brightness monitor at the Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences, we collected data from 22 dark clear nights and 90 moon nights. We first measured the sky brightness vari-ation with time for dark nights and found a clear correlation between sky brightness and human activity. Then with a modified sky brightness model of moon nights and data from these nights, we derived the typical value for several important parameters in the model. With these results, we calculated the sky brightness distribution under a given moon condition for the Xinglong station. Furthermore, we simulated the sky brightness distribution of a moon night for a telescope with a 5 ◦ field of view (such as LAMOST). These simulations will be helpful for determining the limiting magnitude and exposure time, as well as planning the survey for LAMOST during moon nights. Key words: Moon — scattering — site testing — telescopes