Above is a theoretical rendering of a white dwarf, the collapsed husk of a low-mass or medium-mass star. Interestingly enough, these strange cosmic objects—which begin their existence as intensely hot balls of carbon the size of the Earth—may eventually cool off and crystalize into giant space diamonds.
White dwarfs are made up of free-floating hydrogen and helium nuclei and degenerate electrons—and their mass is supported by the nature of these electrons.
But degenerate electrons, like any other material, have a specific material strength. What happens if they’ve, well…just got too much stuff to support?
Now that we’re finally talking about white dwarfs, we’re getting into the really cool stuff.
In my last post, we explored planetary nebulae, and we left off with a question: where does the fast wind that forms planetary nebulae come from? Well, remember that planetary nebulae are formed from the atmospheres of medium-mass stars, but there’s still the stellar interior to worry about.
White dwarfs are objects comparable in size to our own Earth. They are the remains of medium-mass stars like our own sun. Often, you can see a white dwarf at the center of a planetary nebula with a large telescope. Together, they form what’s left of a star after it loses stability completely.
Depending on their mass, stars can remain stable for millions and even billions of years. The most massive stars live for “only” about 10 million years, but models predict that the least massive live for much longer—longer than cosmologists believe the universe has existed.
As stars exhaust their fuel, their internal structures change drastically. Their cores contract, but their outer layers are forced to expand, and they become giants. You’d think the next thing we’d cover would be what happens to these giant stars, right?
Well…not quite! At this point, something downright weird is going on in their cores, and it’s well worth a closer look…