A man-made nuclear explosion primarily produces a wide range of electromagnetic radiation, including visible light, infrared radiation, ultraviolet radiation, and high-energy gamma radiation. However, the most intense and immediate release of energy is in the form of thermal radiation and high-energy gamma rays.
During the initial stage of a nuclear explosion, an intense burst of thermal radiation is emitted. This thermal radiation consists mainly of high-energy photons in the visible, ultraviolet, and infrared portions of the electromagnetic spectrum. The exact distribution of energy across the spectrum depends on various factors such as the yield and design of the nuclear device.
In addition to thermal radiation, a significant amount of high-energy gamma radiation is also released during a nuclear explosion. Gamma rays have the highest energy among the electromagnetic spectrum and are highly penetrating. They are capable of ionizing atoms and can cause severe damage to living tissues.
In the case of a supernova, which is a powerful explosion of a massive star at the end of its life, a wide range of electromagnetic radiation is produced. Supernovae emit radiation across the entire electromagnetic spectrum, from radio waves to gamma rays. However, the distribution and intensity of radiation at different wavelengths vary during different phases of the explosion.
Initially, after the core collapse of the star, a burst of high-energy gamma rays is emitted, followed by the release of X-rays and ultraviolet radiation. As the explosion progresses, visible light becomes dominant, and the supernova may become brighter than an entire galaxy. Later in the evolution of the explosion, the energy output shifts to infrared radiation and radio waves.
In summary, while man-made nuclear explosions produce a significant amount of thermal radiation and high-energy gamma rays, supernovae emit radiation across the entire electromagnetic spectrum, with different wavelengths dominating at different stages of the explosion.