A tiny red dot in the sky turned out to be a 'black hole star'

Night had fallen on the hilltop. Professor Pip fumbled in his lab-coat pockets and pulled out a small brass telescope, a plaid blanket, and — after a moment of searching — a metal funnel and a jug of water.

"Look up, my fellow scientists," he whispered.

Mia and Leo tipped their heads back. The sky was a swirl of stars, and one — one strange pinprick near the horizon — glowed a deep, deep red.

"Is that a red star?" Leo asked.

"It looks like a star," Pip said, adjusting his crooked spectacles. "But astronomers just discovered it's actually a black hole wearing a star's coat. They call it a black hole star. Curiouser and curiouser!"

Mia frowned. "But black holes are dark. That's why they're called black. How can a black hole shine?"

"AH!" Pip clapped his paws. "Best question of the evening. Let me show you." He plopped the funnel over the mouth of the jug and picked up a small pebble.

"A black hole is a place in space where gravity pulls so hard that even light can't escape. It's like this funnel — anything that comes close spirals in and disappears."

He tipped water into the funnel. The water swirled — faster, faster — SLOSH-WHOOSH! — and vanished down the neck of the jug.

"See how the water spins around the outside before it falls in? That's called an accretion disk," Pip said, sounding out the word slowly. "Gas and dust circle a black hole the same way. And because everything is squished and spinning so fast, it gets incredibly hot — hotter than a hundred suns."

"Hot things glow!" Mia exclaimed.

"Precisely!" Pip's tail swished happily. "The black hole itself is invisible. But the gas swirling around it gets so hot it glows brighter than a whole galaxy. From very far away, that glow looks like… a star."

Leo stared at the red dot. "So it's like a lightbulb, but the bulb part is invisible and only the glow shows?"

"Exactly right!" Pip beamed. "And here's the truly astonishing part. That light has been traveling for billions of years to reach your eyes tonight. When it left, dinosaurs didn't exist yet. Earth didn't exist yet."

They all sat quietly for a moment, looking up.

"So many of those little dots up there," Pip said softly, "might not be stars at all. They might be black holes wearing disguises. Now I wonder… how many more are hiding?"