Answer:
The length of time taken before the star's explosion and the time when it reaches our planet is converted into a distance. This is known as lightyears which is the distance light travels in one year. Distance is equal to time*speed. Therefore time (31,556,926 seconds)* speed (299,792.458 kilometers/second)= distance (9.4605*10^12 km or about 9,500,000,000,000 kilometers).