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SandyDelights t1_ivjmts5 wrote

Reply to comment by go_half_the_way in Bizarre star may have a solid surface, according to X-ray observations. Astronomers have now spotted a super strange one that seems to have a solid surface. Its intense magnetic field is strong enough to overcome its blistering temperatures and “freeze” its outer layers into a solid crust. by MistWeaver80

Objects don’t need to continuously generate energy to produce light – white dwarves are the “dead” cores of stars, but it takes an extraordinary long time for them to radiate away the remnant heat.

The distinction here being they don’t need to generate energy because they already have generated that energy (in the form of heat), so the light (in the case of white dwarves) is just the heat radiating into space as the dead star slowly cools (or causes the star to cool, whichever you prefer).

Good example is a stove burner: turn it on, crank it up to high so it’s burning hot and glowing red, then turn it off, pull the plug if you want to. Does the red go away instantaneously, or does it slowly darken as it cools?

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go_half_the_way t1_ivjn27l wrote

Thanks. Makes sense. So this is an immensely hot solid ball slowly cooling.

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SandyDelights t1_ivjnutq wrote

Oh, not going to say that – I was explicitly answering the general question of “if it’s giving off enough light to be a star now is that energy being generated and how does it ‘get out of the solid surface’”, i.e. you don’t need to produce energy to produce light (you just need some form of energy present for it).

That said, yes, but there are a lot of caveats – this article covers it really well and in fairly simple terms.

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