OpenAcc Parallel Schemes for Accelerating Asteroidal Period Search

The rotational period of asteroids may provide important information about the inner structure of asteroids and reveal the formation history of our solar system. Most inversion methods of searching asteroidal periods are extremely time-consuming. Therefore, some parallel technologies, such as OpenAcc, can be used to accelerate the search process. In this article, two parallel schemes of OpenACC with CPU and GPU are presented for accelerating the period searching of asteroids from light curves. The Intel i7-9750H CPU is used to execute the CPU's serial computing and parallel computing. Furthermore, the Tesla V100-SXM3 GPU is used to execute the GPU's parallel computing. Compared with the serial scheme, the maximum speedup ratio of the CPU parallel scheme is 30.5x, while that of the GPU parallel scheme is 29.9x. The experiment results indicate that the GPU parallel scheme is more suitable for large-scale parallel computing of searching asteroidal periods. Additionally, an initial period estimation method is proposed to reduce the searching interval. It is confirmed numerically to be efficient and feasible in the application of searching four real asteroidal periods, and the derived periods are practically consistent with the results obtained by other methods.