A spiral arm in our Galaxy seen in the constellations Vela, Carina, Crux, and Centaurus. It may be a continuation of the Sagittarius arm, rather than a completely separate feature.
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。