Design and application of a follow-up observation system for optical transient sources.

[Objective] In recent years, numerous survey optical observation instruments, including the Tsinghua University-Ma Huateng Survey Telescope, have been constructed and put into operation domestically and internationally. These telescopes have generated massive amounts of data through continuous observations, discovering numerous high-value transient sources. To address the increasing number of transient sources, limited domestic telescope observation resources, and enhance the follow-up observation response capability of the Tsinghua University-Ma Huateng Survey Telescope, the Nanshan Transient Source Follow-up Observation System in Xinjiang was designed and constructed. [Methods] The research team prioritized mature commercial products, considering equipment stability, cost-effectiveness, and ease of future upgrades within a limited budget. They tackled challenges related to the hardware of the supernova and optical variables automated follow-up observing system (SNOVA) dealing with mismatched dimensions of commercial off-the-shelf products and inadequate original load-bearing designs. Custom mechanical interfaces were created between subsystems during assembly and adjustment to resolve issues such as back focal distance matching of the telescope optical system and the filter system load-bearing capacity. Building on this hardware setup, they achieved coordinated control of each subsystem through a unified upper-level control software by debugging control software drivers and interface protocols. [Results] The SNOVA successfully implemented a closed-loop workflow for routine follow-up observations. Each night, the TMTS survey system processes data and cross-references it with databases to identify key targets for further observation. These targets are filtered based on the detection performance criteria, generating an observation system list with parameters such as target name, coordinates, filters, exposure time, and the number of repeats. This list is synchronized to the SNOVA main control machine via FTP. After an astronomical twilight, the environmental monitoring system assesses whether the conditions are suitable for observation. If so, the astronomical dome is remotely opened, and the ACP control software sequentially activates each subsystem. Once the detector cools, the system performs autofocus based on temperature and other parameters before starting the night observation tasks. Upon completion, the SNOVA data processing system automatically scans the observation data folder for the night and performs data preprocessing based on bias, dark current, flat field, and target source data. [Conclusions] Through careful selection, installation, and debugging of hardware and software, the project team successfully automated the operation of the entire follow-up observation system, which provides high-quality data for follow-up observations of transient sources and aids in precisely determining their physical parameters and evolutionary properties. Additionally, it offers an effective means for conducting remote observation internships. The SNOVA boasts high hardware stability, rapid iteration of control software drivers, and low post-development costs. With the adaptive modifications of the project team, the SNOVA is characterized by low set-up cost and strong portability, making it an excellent reference for similar projects and suitable for the follow-up observation needs of the numerous survey projects. [ABSTRACT FROM AUTHOR]