Novas and Supernovas
Novas and supernovas are all variable stars created by nova ng a nova outburst, the brightness may increase over the course of a few days by several thousand or even dozens of thousands of it will gradually dim, eventually returning to its originai brightness after several or dozens of years.
新星和超新星都是由新星的爆发而产生的变星。新星的爆发有时能在几天时间内将这颗星的亮度增强几千到几万倍，随后它又会渐渐暗弱下去，几年或十几年之后最终回到原来的亮度。The outbursts of supernovas are even more spectacular, increasing their brightness by up to hundreds of millions of times. The ancient Chinese people named such celestial bodies "guest stars". The earliest record on guest stars in China dates back to as early as in the 14th century BC, about a nova near the a Star on the Scorpio Constellation.
超新星的爆发更加壮观，可以将这颗星的亮度增强到几百万倍，中国古人称这类天体为“客星”。中国最早的客星记载是大约公元前14世纪出现于天蝎座（心宿二）附近的一颗新星。
During the period between the Shang Dynasty and the end of the 17th century,78 novas and especially 12 supernovas were recorded in China's historic a rich and systematic record of supernovas is unique in the world.
自商代至17世纪末，中国史书共记载了78颗新星、12颗超新星，这么丰富而又系统的超新星纪事，在世界上是独一无二的。Of all the recorded novas and supernovas, the most brilliant was the superno-va near the Tianguan Star in the Taurus constellation, which lasted two years after its outburst.
在中国史书中所记载的新星、超新星中，最精彩的要算宋至和元年（1054年）出现在金牛座天关星附近的超新星，这颗超新星爆发后达两年之久才变暗。After the birth of the radio telescope in the 1930s, many scholars in the world,in an effort to search for the correspondence beiween the radio source in the Milky Way galaxy and the supernova, carried out detailed research on the ancient re-cords on novas and supernovas. It turned out seven of the twelve supernovas re-corded by ancient Chinese astronomers correspond to the radio source, whichshows the importance of China's records on guest stars to modern astronomic re-search.
20世纪30年代射电望远镜问世后，世界上许多学者为了寻找银河系中射电源和超新星的对应关系，无不对中国古代的新星、超新星记录做详细研究。研究证明，在中国古代的12次超新星记录中，有7颗以上对应着射电源。这充分说明中国古代的客星纪事对现代天文学的研究所起的重要作用。