According to this article, this explosion is hourglass-shaped rather than spherical, due to the previous behavior of the star. https://www.astronomy.com/scienc

According to this article, this explosion is hourglass-shaped rather than spherical, due to the previous behavior of the star. https://www.astronomy.com/science/why-does-supernova-1987a-look-like-a-ring/ https://www.astronomy.com/science/why-does-supernova-1987a-l...