star classification system

The star classification system groups stars based on their temperature, color, and brightness, primarily using spectral types labeled O, B, A, F, G, K, and M. O-type stars are the hottest and bluest, while M-type stars are cooler and redder. Within each spectral type, stars are numbered from 0 to 9, with 0 being hotter. Additional letters like 'L', 'T', and 'Y' are used for cooler, dimmer objects such as brown dwarfs. The system helps astronomers understand a star’s properties, lifecycle, and even potential for hosting planets.