A B-type main-sequence star is a type of star that is larger and hotter than our Sun. These stars have surface temperatures ranging from about 10,000 to 30,000 degrees Celsius. They are typically blue or blue-white in color and are known for their strong ultraviolet radiation. B-type stars are more massive than A-type stars and can be found in various stages of stellar evolution. B-type main-sequence stars are relatively short-lived, usually existing for only a few million years before evolving into red supergiants or other types of stars. They play a crucial role in the formation of heavy elements through nuclear fusion in their cores. Their intense energy output can influence the surrounding interstellar medium, contributing to the birth of new stars.