An Overview of the BOOTES-4 at the Lijiang Observatory

The BOOTES (Burst Optical Observer and Transient Exploring System, http://bootes.iaa.es), is a global network of Robotic Autonomous Observatories (RAOs). It was initiated in 1998 under the leadership of Spain and the collaboration of many other countries. It is dedicated to observation of optical emissions from Gamma-Ray Bursts (GRBs) in the Universe. The fourth station of the BOOTES, BOOTES-4, is located at the Lijiang Observatory (of the Yunnan Observatories) in the southwest of China. As the first Chinese RAO the BOOTES-4 has been in full robotic operation since February 2012. It has a set of instruments identical to those of the BOOTES-2, BOOTES-3, and upcoming BOOTES stations; these include an EMCCD camera on its 0.6m fast-slewing telescope (BOOTES-4/MET) and an all-sky camera (CASANDRA-4). In this paper we present the site construction of the BOOTES-4 and details of its hardware/software systems. The hardware systems have been built to meet the scientific requirements and the needed reliability for robotic operation. The Observatory Manager for the BOOTES-4 is the RTS2 (Remote Telescope System, 2nd version), which is an open-source software system that has been extensively used on many robotic telescopes including all BOOTES ones. We finally describe operational experiences and scientific results obtained with the BOOTES-4 since 2012. With the BOOTES-4 included, the BOOTES now has a larger sky coverage and a more significant role in designated observational tasks than before. The tasks include quick follow-up observation of GRB events, non-stop monitoring of some celestial targets, and acquisition of more precise light curves of GRBs/transient sources.