The Families of Stars-星族
The Families of StarsThe Families of Stars
Astronomers bave been able to classify stars according to colour. They have discovered that stars with different colours have different sizes,and that their surface tempera tures are also different. The larger a star is, the higher surface temperature it has.
From the above table it can be seen that stars are generally divided into five kinds: blue, white, yellow, orange and red. Blue stars are the largest ones, with a diameter of 16,000,000 kilometres. Their surface tetnperature is also the highest, as high as 25,000℃,Then there are yellow stars, 1,600,000 kilometres in diameter and 6,000℃ in surface temperature. Orange stars are smaller,They have a diameter of 1,000,000 kilometres and a surface temperature of 5,000℃.
The smallest kind of stars appear red in colOUr. Their diameter is only one-twentieth of that of blue stars, that is, 800,000 kilometres, and their surface temperature is only, 3,000℃.星族
天文学家能够按照颜色把星星分类。他们发现不同颜色的星星大小也不同，表面温度也有差异。星体越大，其表面温度也越高。
从上表中可以看出星星一般分成五类：蓝、白、黄、橙、红。蓝色的星体最大，其直径为16000 000千米，表面温度也是最高的，可高达25000℃。接下来是黄色的星，直径为1 600 000千米，表面温度为6000℃。橙色的星较小，直径为1 000 000千米，表面温度为5 0000℃。
最小的星体呈红色，其直径只有蓝色星体的1／20，就是说800 000下米，其表面温度只有3000℃。