Stars are science we used to pray to.
"I am the alpha and the omega, and the alpha is 1/137. The omega is useful when making iPads."
Gravity draws things together, compressing light elements until they undergo fusion and start glowing. The mere existence of matter automatically creates shining lights in the darkness, joining things together to create warmth with a more stable result. The laws of physics are surprisingly romantic.
Two sextillion tons of thermonuclear fusion kicks the shit out of a scented candle.
Stars are the source of all light, life, and warmth, and we take their name in vain to describe no-talent carbon wastes on reality TV. "Jesus, what is wrong with reality stars" is triple blasphemy against every noun in that sentence. Which is why we're looking at real stars worthy of your attention.
#5. Intergalactic Hypervelocity Star
Intergalactic hypervelocity star! Astrophysics often sounds like mistranslated anime about space police. Especially since SDSS J0907 is an intergalactic rogue, nicknamed the Outlaw Star, hurtled out of the galaxy by the loss of its partner.
"I'm several billion years too old for this shit."
Outlaw was half of a binary system, a pair of stars orbiting around a shared center, which didn't play by the rules, where "the rules" are "Don't dive into the black hole at the center of the Milky Way if you want to continue existing." In an awesome overlap of astrophysics with action movies, Outlaw's partner was killed, and Outlaw was slingshotted out at escape velocity. The escape velocity of the entire galaxy.
The result is an entire star speeding toward intergalactic space at over two thirds of a million meters per second. A star streaking along at five-hundredth of the speed of its own light. 0.2 percent isn't usually a big number, because we're not usually talking about entire stars and the speed limit of existence. That's the kind of cosmic kinetic energy that would beat Galactus at Chicken.
#4. The Star from the Approximate Beginning of Time
Astrophysicists are wise beyond their years. In fact they're wise beyond almost all years, ever, because they've measured the age of the universe. And found a star that's been here almost as long.
"Damn young stars, you whipper-stellars with your metal and your baggy disk orbits! Get off my globular cluster!"
HD 140283 is 14.5 plus or minus 0.8 gigayears old, compared to the universe's 13.80 plus or minus 0.04 gigayears, and some idiots are already in the comments complaining about that being impossible. It's ironic that many of humanity's worst errors don't understand how to read errors. The star was measured by the Hubble space telescope, a system designed to constantly remind us that the universe is unbelievably awesome.
NASA, ESA, W. Clarkson (Indiana University and UCLA), and K. Sahu (STScI)
And very much a fan of sequins.
This "Methuselah star" was most likely forged in a primeval dwarf galaxy, making the universe even cooler by sounding like a weapon for Thor. It survived when its birth galaxy was shredded by the Milky Way 12 billion years ago. Wow, the Milky Way sounds soft, but it's been floating around killing things like it's trying to create a stellar action hero.
Digital Vision./Digital Vision/Getty
And like most horror villains, it comes out at night.
If Methuselah is out for revenge, it's been biding almost all of time so far. Methuselah is massive confirmation of our calculations of the age of the universe. You'd think it would be easy to confirm things when you're talking about everything, ever. It turns out that measuring cosmic parameters with bald monkeys from thousands of light-years away leaves a lot of room for problems. But the great thing about science is solving problems. And the great thing about stars is that there are so many of them.
Pick a star, any star.
If you keep looking, you can find the perfect example of almost anything. Methuselah was nearby, unreddened; we know its chemical composition; it's in the most accurately age-specific region of the Hertzsprung-Russell luminosity-temperature diagram. The star is doing everything but shining its own light on its birth certificate for us.
The universe is about 14 billion years old. We worked that out despite rarely making it to a hundred. Just thinking about that will make permanent changes to your brain, all of them good.
#3. Gravity Wave Radiation
Stars are supported against gravity by the thermonuclear fusion in their cores. Fusing lighter atoms into heavier ones releases energy, but those heavier elements require higher temperatures to fuse again. If the star isn't massive enough to ignite the next element, or if it reaches iron (which, Robert Downey Jr.'s characterization notwithstanding, is stable and can't sustain a star), fusion stops. Then gravity gets to continue the job it started billions of years before: crushing the absolute hell out of everything ever.
Small stars end up as white dwarfs, which are as dense as you can make matter without stomping on the fundamental concept of atoms. Larger stars become neutron stars by doing exactly that.
A helium atom that really has no idea what it's in for.
Most matter is empty space. In atoms, a cloud of electrons orbit the nucleus. In neutron stars, they're stomped into it, negative electrons physically crushed into the positive protons to create an endless mass of neutral neutrons. No space, no charge, no elements, chemistry itself crushed out of existence by all-dominating physics.
The resulting neutronium is 40 trillion times denser than lead. If you stood with a spoonful of neutronium, it would fall through the spoon, cut a hole in your foot, and punch through the Earth until it shot through the core and out the other side. Then it would turn around and do it again, and again, and again and again, until it got thermodynamically bored (aka slowed down and stopped by friction). It's a material so solid that merely trying to weigh it shoots your home planet through the heart multiple times. It's as dense as anything can get without giving up on matter entirely and becoming a black hole.
Getty Images/Getty Images
Black holes: The full stop at the end of everything.
So we have white dwarfs, the densest thing you can get without breaking atoms, and neutron stars, the densest thing you can get without breaking the existence of matter, and PSR J0348+0432 has both. A binary system built out of the two densest anythings, ever, orbiting each other every two and a half hours. A system twice the mass of the sun whipping around in less time than it takes to watch The Hobbit. That's not an orbit, that's how you blend space-time. Large masses can bend space, but these are rippling it, jumping up and down on the fabric of reality so hard that they're sending out waves of existence-deformation.
We can't observe these waves directly (although you must remember that every such statement in science ends with YET), but we can measure their effects. Scientists watched the stellar remnants spinning around -- the intelligent opposite of Dancing With the Stars -- and found that they're slowing down at exactly the rate predicted by gravitational radiation. And the constant loss of energy means that -- like with all the most heavenly dancing -- they're getting closer and closer as the fundamental forces of physics shout "Kiss! KIISSSSSSS!" And if their swirling sweeps waves across reality, their collision will be a bang so big, it'll make the heavens move.