Simulations of opportunities for simultaneous observations of the sun by the ASO-S and the CHASE

During 2025, solar activities will remain active. It is a good chance to monitor and study the insight mechanisms inside the Sun. Solar physicists are quite concerned about the valuable observations of the Sun in the maximal solar cycle. There are two Chinese assets, the CHASE and the ASO-S in near-Earth space. They are expected to be aimed at observing the Sun so that more discoveries about the Sun might be disclosed. Some scientists are involved in the CHASE and the ASO-S missions; so the joint observations of the Sun by both the ASO-S and the CHASE become easier to be carried on. Authors of this paper have made tentative simulations of opportunities for simultaneous observation of the Sun by the ASO-S and the CHASE. During the simulation, authors have considered the orbit data set from Feb. 24, 2025, to Feb. 24, 2026, for both the ASO-S and the CHASE. The simulations have shown that there are about 2742 intervals when simultaneous observations by the ASO-S and the CHASE are unavailable; the average interval is about 16.5 min, and the maximal interval is about 22.6 min. There are three prime times for simultaneous observations of the Sun, which include the interval from 24 Feb. 2025 04:15:05.150 UTC to 11 May 2025 12:59:11.823 UTC, the interval from 1 Aug. 2025 03:18:38.994 UTC to 30 Oct. 2025 18:27:08.476 UTC, and the interval from 9 Feb. 2026 21:49:09.334 UTC to 24 Feb. 2026 04:15:05.150 UTC.