Cosmic Drama

The Fate of the Solar System

A supernova can be brighter than the combined radiance of all the other stars in the galaxy within which it is embedded.

Planets near stars much more massive than the Sun will be melted and frizzled by their sun when it becomes an erupting supernova, since these massive stars with higher temperatures and pressure run rapidly through their store of nuclear fuel, and their lifetimes are thus much shorter than the Sun’s.  In fact, a star tens of times more massive than the Sun can stably convert hydrogen to helium for only a short period of time – less than few millions years before moving on to more exotic nuclear reactions. All those massive blue-white supergiant stars in Orion are destined in the next few million years to become supernovae.

The essential preliminary to a supernova explosion is the generation of a massive iron core. Under enormous pressure, the free electrons in the stellar interior are melted with protons of the iron nuclei, the equal and opposite electrical charges canceling each other out;  the inside of the star is turned into a giant atomic nucleus, occupying a much smaller volume than the precursor electrons and iron nuclei.

A silicon fusion occurs and the core implodes violently, the exterior rebounds and a supernova explosion results.

On massive stars thus there is not enough time for the evolution of advanced forms of life on any accompanying planets. There will be not any beings there that could see their star become a supernova. Indeed, if intelligent beings live long enough to understand supernovae, their star is unlikely to become one.

The awesome supernovae explosion ejects into space most of the matter of the precursor star - residual hydrogen, helium, carbon, silicon, iron, uranium… Remaining is a core of hot neutrons, bound together by nuclear forces. This core is a single atomic nucleus with very heavy atomic weight. It becomes a neutron star thirty kilometers across: a rapidly rotating, tiny, shrunken, dense, withered stellar fragment. As the core of a massive red giant star collapses to form such a neutron star, it spins faster. The neutron star at the center of the Crab Nebula is an immense atomic nucleus, about the size of Manhattan, spinning thirty times a second. Its powerful magnetic field, amplified during the collapse, traps charges particles rather as the much tinier magnetic field emit beamed radiation not only at radio frequencies but in visible light as well. However, the fate of the inner solar system as the Sun becomes a red giant is grim enough.

Many stars in the Orion Constellation will become supernovae - a continuing cosmic fireworks in the constellation of the hunter. Image: © Megan Jorgensen.