The star Alpha Draconis, magnitude 3.7. It is an A0 giant 303 l.y. away, and was the north pole star about 4800 years ago.
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。