Betelgeuse is a red supergiant star located in the constellation Orion, approximately 650 light-years away from Earth. If Betelgeuse were to go supernova, which is a possibility for such massive stars, the light from the explosion would take approximately 650 years to reach us.
However, it's important to note that Betelgeuse is a variable star, meaning its brightness fluctuates over time. While it has shown signs of potential instability and has experienced noticeable dimming in recent years, it has not yet gone supernova. Supernova events are unpredictable and can occur at any time, but there is no way to accurately predict when Betelgeuse might explode.
If Betelgeuse were to go supernova in the near future, we would witness the event 650 years after the actual explosion occurred. Until then, we can continue to observe and monitor the star's behavior to gain a better understanding of its evolution and potential fate.