Types of Supernovae
Supernovae are the most powerful known objects in the universe. Formed from old stars that collapse and explode, a supernova can emit energy on the scale of \(10^{44} \) joules, or as much energy as the Sun emits in its entire lifetime. Within a few moments of the star's collapse, it's apparent magnitude can increase by orders of 11 magnitude, often times making it the brightest object in its respective galaxy for months on end.
Supernovae are very rare occurrences and happen only once or twice per century. However in the Milky Way, only 6 have ever been recorded, the most recent being noted in 1604, before the invention of telescopes! The lack of supernovae imaging in our galaxy is due to our solar system's position in an arm of the Milky Way where most of the stars exist in the inner core. The obfuscation of light from dust and the ISM makes it nearly impossible to detect supernovae towards the center of our galaxy.
However, data from other galaxies has allowed astronomers to characterize two main types of supernovae distinguished in their light curves and process of formation. Type I supernova have a much sharper maximum peak before their light intensity gradually drops. It is believed that these types of supernova are caused by White Dwarf stars in binary systems with much larger Red Giant. The larger star gradually pulls mass from the white dwarf until it goes below a stable limit and begins to collapse on itself, causing the supernova explosion.
Type II supernova have less dramatic light curves and occur over a longer period. The progenitor star for a type II supernova is Red or Blue Supergiant. This is the more typical type of supernova and occurs when the fusion of the star's core dies out causing the gravitation equivalence to collapse and the star implodes. This explosion is typically linked to hydrogen emission lines which helps identify the type of supernova.
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