3 ms·

What are some thoughts about why we're basically seeing a flat ring, rather than a spherical shell of a cloud in all directions?

• readyplayernull 2y ago
  High speed rotation in an axis?
• ASalazarMX 2y ago
  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...
• jdhwosnhw 2y ago
  The column mass (ie, the spatial density multiplied by the length of the observer’s line of sight through the material) is highest at the limbs when looking at a gaseous shell. So shells like this look like rings from all angles. A related effect called limb darkening is the edges of the sun always look less bright, independent of viewing angle
• alfiopuglisi 2y ago
  The ring is not a product of the supernova. It's pre-existing material, that is being energized by impact of the supernova ejecta (it took a few months for it to start brightening). There are actually three rings, a smaller one around the previous star's equator, and two larger ones above and below. The hourglass-like figure is actually quite common, produced by the star rotaton.