Can you advise me which journal is more suitable for submitting the article entitled "Novel metaheuristic optimization algorithm based on astronomy" which has about 40 pages?
Of course it (publishing a paper) all depends on the quality of the paper, and the field in which the heuristic is being applied. There is the European Journal of Operational Research, the Journal of Heuristics, and many other computer science and AI-related journals. You should visit the Clarivate Journal Citation Reports website to browse the journals related to your topic.