* Hotter stars emit more blue light: This is because hotter objects emit more energy at shorter wavelengths. Blue light has a shorter wavelength than red light.
* Cooler stars emit more red light: Cooler objects emit more energy at longer wavelengths. Red light has a longer wavelength than blue light.
Here's a simplified analogy:
Think of a piece of metal being heated. As the metal gets hotter, it first glows red, then orange, then yellow, then white, and finally a bluish-white. This is because the peak of the emitted radiation shifts towards shorter wavelengths as the metal gets hotter.
The Stellar Classification System:
Astronomers use the spectral classification system to categorize stars based on their temperature, which is directly related to their color. The system uses letters from hottest to coolest:
* O: Blue (over 25,000 K)
* B: Blue-white (10,000 - 25,000 K)
* A: White (7,500 - 10,000 K)
* F: Yellow-white (5,000 - 7,500 K)
* G: Yellow (3,500 - 5,000 K - our Sun is a G-type star)
* K: Orange (2,500 - 3,500 K)
* M: Red (below 2,500 K)
In summary, the color of a star is a direct indicator of its surface temperature. Hotter stars are bluer, while cooler stars are redder.
