An object beyond the Solar System. The term is not usually applied to individual stars, but to objects of the kind found in the Messier Catalogue and New General Catalogue, i.e. star clusters, nebulae, and galaxies.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。