apparent magnitudecolor index diagram

例句：

1. 1.The astronomer used the apparent magnitude to determine the star's brightness.
   天文学家使用视亮度指数来确定恒星的亮度。
2. 2.The color index diagram helped us understand the relationship between different colors.
   颜色指数图帮助我们理解不同颜色之间的关系。
3. 3. The diagram shows the variation in the apparent magnitude of stars across different regions.
   图表显示了不同地区恒星视亮度的变化。