Betelgeuse, a red supergiant star in the constellation Orion, has not gone supernova. Supernovae are unpredictable events, and while Betelgeuse has exhibited some unusual behavior, including dimming in brightness, it has not yet exploded as a supernova.
If Betelgeuse were to go supernova in the future, it would likely become a spectacular event visible from Earth. The exact duration of how long we would be able to see the supernova would depend on various factors, including the distance between Betelgeuse and Earth and the characteristics of the explosion itself. Generally, a supernova can remain visible for several weeks to months, gradually fading over time.
However, it is important to note that predicting the timing of supernovae is challenging, and astronomers cannot accurately determine when Betelgeuse or any specific star will go supernova. Supernovae occur when massive stars exhaust their nuclear fuel and undergo a catastrophic collapse. While Betelgeuse is a candidate for a future supernova, we cannot currently predict if or when it will happen. Continued observations and monitoring of the star will provide valuable data that may help refine our understanding of its behavior and potential for a supernova event in the future.