12/29/2022 0 Comments Shrink to fit in word 2016![]() ![]() Possible causes are an accumulation of material from a binary companion through accretion, or a stellar merger. ![]() In the first class of events, the object's temperature is raised enough to trigger runaway nuclear fusion, completely disrupting the star. Theoretical studies indicate that most supernovae are triggered by one of two basic mechanisms: the sudden re-ignition of nuclear fusion in a degenerate star such as a white dwarf, or the sudden gravitational collapse of a massive star's core. The most recent naked-eye supernova was SN 1987A, the explosion of a blue supergiant star in the Large Magellanic Cloud, a satellite of the Milky Way. These supernovae would almost certainly be observable with modern astronomical telescopes. Observations of supernovae in other galaxies suggest they occur in the Milky Way on average about three times every century. The most recent directly observed supernova in the Milky Way was Kepler's Supernova in 1604, but the remnants of more recent supernovae have been found. The word supernova was coined by Walter Baade and Fritz Zwicky in 1929. Adding the prefix "super-" distinguishes supernovae from ordinary novae, which are far less luminous. In Latin, nova means "new", referring astronomically to what appears to be a temporary new bright star. Supernovae are more energetic than novae. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months. The original object, called the progenitor, either collapses to a neutron star or black hole, or is completely destroyed. This transient astronomical event occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion. SN and SNe) is a powerful and luminous stellar explosion. SN 1994D (bright spot on the lower left), a type Ia supernova within its host galaxy, NGC 4526Ī supernova ( / ˌ s uː p ər ˈ n oʊ v ə/ pl. ![]()
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