Like a Diamond in the Sky

Did you feel sad when Pluto got demoted from its status as a planet to a dwarf planet? The debate around that is because the classification is arbitrary: how spherical does an object have to be to be called a planet? How big must be it compared to other objects in orbit at the same distance? Why those values? None of these answers can be derived from the laws of physics, hence the controversy.

Ok, but the difference between a planet and a star? Surely, that’s easy, right? A star emits its own light whereas a planet doesn’t. Simple? Even when a star runs out of fuel, we don’t call it a planet.

Until we found the “diamond planet”, that is!

Huh? Long, long ago, there was this pulsar. Oversimplified, a pulsar is a star that has collapsed and is spinning really fast. Like 170 times a second. As it spins, the pulsar shoots out deadly radiation. How deadly? Suffice to say, it’d make our nukes feel puny by comparison.

There was this other star that got too close to this pulsar. Ever since, as Stephanie Warren writes:

“The pulsar’s rays have been blasting the star for millions of years. Slowly the star’s surface wore away, until 99.9 percent of it disappeared.”

And now all that’s left is the center of that star, what is still 5 times as large as the earth. And it’s entirely made of diamond. Hence the name “diamond planet”!

So we have this star that became a planet! Suddenly, Pluto’s fate doesn’t seem so bad, does it? Or wait: the star that became a planet is still a diamond planet, something very special. Until and unless, of course, we find other such planets.

All these transformations remind me of that line that Commudus said in the movie, Gladiator:

“A General who became a slave, a slave who became a Gladiator, a Gladiator who defied an empire.”

And I guess that nursery rhyme got it all wrong: what’s twinkling out there “like a diamond in the sky” isn’t a star. It’s a star that became a planet, Gladiator style!