Nearest star – At “just” 149,600,000 km (93,000,000 mi) from Earth, the Sun is considered astronomically close. The next nearest star, Proxima Centauri,is 4.2 light years away, or 40,000,000,000,000 km (24,000,000,000,000 mi).The pioneering work carried […]

Astronomers classify stars according to the Morgan-Keenan system, which categorizes them by surface temperature, from hottest (O) to coolest (M). They may be further subdivided by temperature and brightness. The hottest stars are also the […]