Here's how it works:
* Spectral Class: Astronomers categorize stars based on their spectra, which is the pattern of light they emit.
* Temperature: The temperature of a star directly influences the types of elements that are excited and emit light. Hotter stars emit more blue light, while cooler stars emit more red light.
* Classification: The spectral classes are designated by letters, from hottest to coolest: O, B, A, F, G, K, and M.
* O: Blue, hottest, 30,000 K and above
* B: Blue-white, 10,000 - 30,000 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 star)
* K: Orange, 2,500 - 3,500 K
* M: Red, 2,000 - 2,500 K, coolest
Important Note: Each spectral class is further subdivided into ten numbered subclasses (e.g., G0, G1, G2...G9). This gives a finer categorization of stars within each temperature range.
