Neutron stars are made up of collapsed molecules, really just solid neutrons from edge to edge, under maybe a thin shell - like a millimeter or three - of collapsed normal matter. The electron shell of each atom has been squashed flat under the crushing gravity of all the mass on top it. A teaspoon of neutronium - what sciency types like to call neutron star matter - would weigh thousands of tons. That teaspoon of material all by itself would have a gravitational field you could detect with your own senses from a distance - not a big distance, but you don't want to get too close, either. A neutron star's escape velocity can approach a third of the speed of light, get too close to a mass that small and heavy, next thing you know you're plated around in a thin layer.
We're inclined to think that neutron stars are bright, because we call them "stars," but the fact is they aren't. I mean, they are, but they're radiating from such a small surface that by the time their light reaches us here on Earth, they look pretty darned dim. But coming as they do from a former star, they're pretty hot and glow by the light of their own heat for a few million years. Things that heavy cool off pretty slowly.
Wait, what? I was always amazed by how smart my kids could be. When they were home schooling and taking chemistry, I was utterly useless as a guide. They wound up teaching it to me, and dang if I didn't forget virtually all of it. But while they were trying, patiently, to explain it to me, I was getting it. They still get it, which I envy.
This isn't a recent trend. They've been almost frighteningly smart from way back. Sweetie gave one child a screwdriver to play with one day, and it got weird. She stepped out of the room for a while, came back to fetch something from a cabinet and the handle, very carefully stuck in place with a dab of butter, came loose in her hand. She grinned at the mischievous child and grabbed the edge of the door.
The door came loose from the cabinet. Kid #2 had removed the hinge screws. All the screws were neatly stashed in a cereal bowl for safe keeping. All the handles and hinges were carefully put back in place on their doors. He was about four years old.
"Okay," Sweetie said. "Now put them all back together again." And he did, correctly.
This is the same child who, about a week later, was instructed to find his shoes. When Sweetie heard him report his progress, "I can't find them anywhere!" she looked over to see him peering carefully at the corners of the ceiling.
We must hope that that was the last place he was looking. Eventually they were indeed found, and they weren't on the ceiling.
My point is that we are all Neutron Stars. We are bright, but we are dense. Some less than others, but be assured that the moniker must fall upon you eventually. If you've ever slapped your own forehead because nobody was around to do the slapping for you, you have been a Neutron Star.
Case File: driving along, thinking carefully through the process of how to stab the clutch, grab a gear just so, feather the clutch back out while adding gas, and proceeding with the perfect gear change. One of my kids learning to drive? Not hardly. That was me! About six months ago. I slapped my own forehead. I'm a Neutron Star.
How's that make him a Neutron Star?
I was driving an automatic at the time. No clutch. So if you stomp any pedal with your left foot, well by golly everything just comes to a violent stop doesn't it? Sweetie looked around, yelling, "What? What?" I had to admit what had happened. I can't describe the face she made when I got around to admitting I'd forgotten what car I was driving.
Neutron Star. Bright, but dense. Sometimes it's you.