I was at a museum recently, and there was a display on neutron stars. It said that neutron stars are made only of neutrons, which honestly didn't make much sense to me - neutrons decay very quickly on their own, so how do neutron stars "last", so to speak?

So naturally, I checked wikipedia, which provides this diagram:

Electrons and protons do seem to be present. Nowhere is there a "layer" that's only neutrons.

This leads to two questions:

1. Is Wikipedia wrong, or the museum (normally I'd trust wikipedia, but this is a not-insignificant museum that I went to)?
2. Is there anything that could explain the museum display if wikipedia is right?

I was at a museum recently, and there was a display on neutron stars. It said that neutron stars are made only of neutrons, which honestly didn't make much sense to me - neutrons decay very quickly on their own, so how do neutron stars "last", so to speak?

So naturally, I checked wikipedia, which provides this diagram:

Electrons and protons do seem to be present. Nowhere is there a "layer" that's only neutrons.

This leads to two questions:

1. Is Wikipedia wrong, or the museum (normally I'd trust wikipedia, but this is a not-insignificant museum that I went to)?
2. Is there anything that could explain the museum display if wikipedia is right?