Every Type of Star in the Universe

[00:00:00]Look up on a clear night and every point of light you see is a star. They look the same, tiny, white, still, but they are not. Out there in the dark, some stars are so small they barely burn.

[00:00:12]Others are so massive they could swallow our entire solar system and a few are so violent that getting close to them would tear the atoms out of your body. Today, we're counting down every type of star in the universe from the gentlest to the most terrifying. And the last one on this list is a monster that shouldn't be possible.

[00:00:32]Number 10, the red dwarf. Let's start small. Red dwarfs are the smallest, coolest, and faintest true stars in existence. They are so dim that not one is visible to the naked eye from Earth even though they are everywhere. Red dwarfs make up around 70% of all the stars in our galaxy. The most common star in the universe is one you have never seen, but here is what makes them extraordinary. Because they burn their fuel so slowly, so patiently, a red dwarf can live for trillions of years.

[00:01:03]The universe is only 13.8 billion years old, which means not a single red dwarf has ever died, not one. They are all still out there quietly burning, barely getting started. Number nine, the yellow dwarf. This is our star, the sun. And despite how it dominates our sky, it is, by cosmic standards, thoroughly average.

[00:01:24]Not too big, not too small, not too hot, not too cold. It has burned steadily for 4 and 1/2 billion years and it has about 5 billion left. Every second, it converts millions of tons of itself into pure light. And that light is the only reason anything on Earth is alive. It is an ordinary star, but it is our ordinary star. Number eight, the red giant. Now we come to what happens when a star like the sun starts to die. When a yellow dwarf runs out of hydrogen in its core, it does something strange. It's swells enormously, hundreds of times its original size, its surface cooling into a deep angry red. This is a red giant, and in about 5 billion years, our sun will become one. When it does, it will expand past Mercury, past Venus, swallowing them whole, and it may reach far enough to consume the Earth itself.

[00:02:17]The star that gave us life will be the one that ends it. Number seven, the white dwarf. When a red giant finally collapses, it leaves behind something remarkable. A white dwarf is the exposed burnt-out core of a dead star, and the numbers are hard to believe. A white dwarf is roughly the size of the Earth, but it contains as much mass as the entire sun crammed inside it. The density is staggering. A single teaspoon of white dwarf material would weigh several tons here on Earth. It no longer burns, it has no fuel left, it simply glows, slowly cooling for billions of years. A white dwarf is a corpse, but it is a corpse that shines. Number six, the blue giant. Now we go the other way, into the truly massive. Blue giants are enormous, blindingly bright, and searingly hot. Their surfaces can reach 50,000° which is why they glow blue instead of yellow, and they burn through their fuel at a reckless pace. A red dwarf can live for trillions of years, a blue giant might last only a few million.

[00:03:21]They are the rock stars of the cosmos.

[00:03:24]They burn brilliantly, they burn fast, and they die young. Number five, the red supergiant. These are the largest stars in the universe by sheer volume, and their size is difficult to comprehend. Take Betelgeuse in the shoulder of Orion. If you placed it where our sun is, its surface would extend past Mercury, past Venus, past Earth, past Mars, out toward Jupiter.

[00:03:48]Our entire inner solar system would be inside it. And Betelgeuse is not even the biggest. There are super giants so vast that light itself takes hours to cross them. Number four, the neutron star. Here is where things stop making sense. When a massive star explodes as a supernova, its core can collapse into something almost impossible. A neutron star is a city-sized object 12 miles across containing more mass than our entire sun. It is the densest thing in the universe that is not a black hole. A single teaspoon of neutron star material would weigh about a billion tons. And they spin. Some neutron stars rotate hundreds of times every single second whipping around faster than a kitchen blender while being heavier than the sun.

[00:04:32]Number three, the pulsar. Some neutron stars do something even stranger. As they spin, they fire out two intense beams of radiation from their magnetic poles like a lighthouse sweeping across the ocean.

[00:04:44]And if one of those beams happens to sweep past Earth, we detect a pulse, then another, then another, perfectly regular like a cosmic metronome. When the first pulsar was discovered, the signal was so precise, so artificial-looking, that scientists briefly wondered if it was a message from aliens. It wasn't. It was a dead star spinning in the dark keeping better time than almost any clock we have ever built. Number two, the magnetar. And now the most terrifying object on this list.

[00:05:14]A magnetar is a neutron star with a magnetic field so powerful it defies belief. It is the strongest magnetic force known to exist anywhere in the universe. Here's what that actually means. If you came within a thousand miles of a magnetar, its magnetic field would not just kill you. It would distort the very atoms in your body stretching the electron clouds until your chemistry stopped working. You would be destroyed at the atomic level before you ever felt a thing. And they occasionally release starquakes cracking their crust and unleashing more energy in a fraction of a second than our sun makes in hundreds of thousands of years.

[00:05:51]And number one, the hypergiant. The largest, brightest, and most extreme stars that the universe has ever produced. A hypergiant can shine with the light of millions of suns. Its radiation is so intense that it constantly blows its own outer layers off into space. These stars sit right at the edge of what physics allows a star to be. Any bigger and they would tear themselves apart. They burn with unimaginable fury for a couple of million years, then detonate in explosions that can outshine an entire galaxy. Some collapse directly into black holes, disappearing without a trace. They are the shortest-lived, most violent, and most magnificent things that will ever burn in this universe.

[00:06:32]So, the next time you look up at the night sky, remember what you are actually seeing. Not a field of identical white dots, but a graveyard, and a nursery, and a battlefield. Gentle little red dwarfs that will out- live everything. Corpses of dead suns still glowing. Monsters spinning in the dark waiting to explode. Every single one of those tiny points of light is a story, and almost all of them will still be burning long after we are gone.