translation.en: But the alarming thing is that astronomers recently have been studying stars that are similar to our Sun, and they've found that a number of them, when they're about the age of our Sun, brighten by a factor of as much as 20. Doesn't last for very long.
translation.zh: 但令人警醒的是，近来天文学家通过对 与太阳相似的恒星研究发现 其中一些恒星当到了跟太阳年龄相同的时候， 光度是原来的20倍，并维持不了很长时间。