Blue supergiants are massive stars that are much larger and hotter than our Sun. They have a blue color due to their high surface temperatures, which can exceed 20,000 degrees Celsius. These stars are typically more than 10 times the mass of the Sun and can shine brightly for only a few million years before exhausting their nuclear fuel. When blue supergiants reach the end of their life cycle, they often explode in a spectacular event known as a supernova. This explosion can outshine entire galaxies for a short time and may leave behind a neutron star or a black hole.