Science Common Sense

1799 - What is the relationship between star color and spectral type in understanding stellar evolution?

In stars, color and spectral type are closely related.

The color of a star is a result of its surface temperature: - Blue stars: very hot (up to 50,000°C) - White stars: hot (around 10,000°C) - Yellow stars (like the Sun): medium (around 5,500°C) - Red stars: cooler (around 3,000°C to 4,000°C) - Brown dwarfs (almost stars): very cool (around 2,000°C)

Spectral type is like a star's fingerprint: a way to identify the star based on the colors of light it gives off. It's also related to surface temperature. The main spectral types, in order from hottest to coolest, are:

• O (Blue)
• B (Blue)
• A (White)
• F (White-Yellow)
• G (Yellow, like the Sun)
• K (Orange-Yellow)
• M (Red)
• L (Brown)

Understanding the relationship between star color and spectral type helps us learn about a star's age, composition, and stage of life. For example, a red star may be a "red giant" - an older star that's expanded and started to cool down.