南方基地知识库

丽江2.4 m望远镜作为目前国内最大口径的通用型光学望远镜，在我国的夜天文观测领域有着十分重要的地位。从近几年观测时间分配的整体情况来看，云南暗弱天体成像光谱仪（Yunnan Faint Object Spectrograph and Camera, YFOSC）的光谱观测在2.4 m望远镜总观测时间中的占比最多，因此，提高其光谱观测效率和数据质量成为保证望远镜稳定科学产出的关键因素。从影响光谱观测效率的两个重要因素——星像入狭缝和望远镜闭环跟踪出发，介绍了提高2.4 m望远镜光谱观测效率和质量的方法。经实际测试，采用新算法的星像入狭缝精度提高了50%左右，时间缩短了7 min左右；望远镜1 h闭环跟踪精度优于0.5″,同时在像平面上的星像位置偏移量不大于1.8 pixel。 

Lijiang 2. 4-metre telescope, as the largest general-purpose optical telescope of China currently, plays a very important role in the field of night astronomy observation. From the recent distribution time of observation, the spectrum observation of Yunnan Faint Object Spectrograph and Camera ( YFOSC) accounts for the largest proportion of the total observation time. Thus improving its spectrum observation efficiency has become the key factor in ensuring the telescope's stable scientific output. This paper disusses two key factors which affect the efficiency of YFOSC spectrum observation—acquire stars into slit and close-loop guiding of telescope, and introduce the way of improving the quality and efficiency of YFOSC spectrum observation. After the actual test, it is concluded that using the new algorithm makes the accuracy of star image into slit increase by about 50%, and its time shortened by about 7 minutes; while the accuracy of telescope close-loop guiding is better than 0. 5″ in 1 hour, and the offset of stars on the image plane is not more than 1. 8 pixel.