Paul-Baker systems with 4° fiat field and 5° flat field are studied. Their light obstructions under different f/ratios of the primary mirror are analy
We thank Dr. Dave Green (MRAO, UK) for one comment and one identified problem in our paper. The comment is that we did not discuss selection effects of the curr
We describe and analyze observations of mutual events of Galilean satellites made at the Yunnan Observatory in February 2003 from CCD imaging for the first time