Nutronstars - how they can put out light?

lundi 2 septembre 2013

I have read about nutronstars, that the electrons and the protons merge together forming nutrons. These stars are very small but with a mass density that is unimagineable. Maybe I have missed something in these explanations I have read, but how can matter such as nutrons send out light if there is no free electrons left? Isn't light photons that originaties from electrons that jumps from a high state into a lower state?

Br.

Vidar