This Star Makes the Sun Look Tiny!

If we shrink Earth down to the size of a basketball, the Sun, in comparison, would be as large as two Hollywood signs stacked on one another. Impressive, right? That is, until you remember that our star is just a yellow dwarf, and out in the universe there are supergiants, in front of which the Sun looks like a mere speck of dust. In 2024, scientists identified a true cosmic monster, a supergiant star so massive it could swallow the Sun along with half the solar system. So who is this new record holder? Why is size not the biggest deal in space? And what does it take to claim the top spot in the universe? The largest star in our night sky after the Sun is, no, not Polaris. In fact, it's the lesser-known Ardoratus, located in the constellation of the same name. It can only be seen from Earth's southern hemisphere. In 2024, for the first time in history, scientists managed to observe the surface of this star in detail, and it didn't disappoint. They discovered that the scorching plasma on Ardoratus is literally boiling, forming giant bubbles. And since the star's radius measures nearly 300 times our Sun's radius, the bubbles on its surface could be as large as our star. Yet even though Ardoratus is the largest star in the night sky, it's far from the largest in the universe. Until recently, that title belonged to UY Scuti. In 2012, astronomers used the Very Large Telescope in Chile to measure three red supergiants at the center of our Milky Way. Among them was UY Scuti, whose radius stunned scientists. It measured 1,708 solar radii. But don't assume this star is just 1,700 times larger than the Sun. Let me explain how that really works. Here are two cubes before you. The side of the white one equals one solar radius, while the side of the gray one equals two. Even though the gray cube's side is only twice as large, it can fit eight white cubes inside it. This principle applies to other 3D objects, like stars. That means the star UY Scuti could hold almost 5 billion of our suns. Or at least it could have if scientists hadn't made a mistake. In 2023, new measurements revealed that the star's radius was actually just 909 solar radii. So, in 2024, the title of the largest star in the universe went to WOHG64, whose radius is over 1,500 times larger than our suns. This colossal star resides in a neighboring galaxy, the Large Magellanic Cloud, located 160,000 light-years away from us. Fortunately, I mean, if we placed WOHG64 at the center of our solar system, it would engulf five out of the eight planets, including Jupiter. WOHG64 is surrounded by a massive dust and gas cloud, formed by an intense stellar wind blowing material off of the giant. This donut of dust, with a mass of nine of our suns, stretches across a full light-year. So WOHG64 rightfully holds the title of the largest star. Or does it? Here's the twist. There's a star much bigger than WOHG64, yet scientists seem to ignore it. That star is the red supergiant Stevenson 2DFK1. Its radius measures 2,150 solar radii. But despite its massive size, scientists seem to overlook it. And there's a reason. Stevenson breaks the laws of physics by exceeding the so-called Hayashi Limit twice to prevent it from being torn apart by internal plasma pressure or crushed into a white dwarf by its own gravity. The star must maintain hydrostatic equilibrium, a delicate balance between gravity pulling inward and pressure pushing outward. This balance defines the relationship between a star's mass, radius, and temperature. Yet Stevenson breaks two of these rules. The limits on both radius and temperature. While the maximum temperature should be 3,500 kelvins, Stevenson's surface temperature is only 3,200 kelvins, cooler than the coldest known supergiants. This suggests there must be an error, either in Stevenson's measurements or our understanding of the laws of physics. For now, WOHG64 still holds the title of the largest star in the universe. But here's the thing. Its title isn't just about size. Stars are also classified as hypergiants not based on size, but on their luminosity. In space, size isn't the only thing that matters. Do you want to see the real record holder in our universe? Here it is. This is R136A1. The radius of this star is just a little over 42 solar radii. But it's a champion in a completely different class. R136A1 is considered one of the heaviest, brightest, and hottest stars out there. Its mass is almost 200 times that of our sun. It holds the title of the second most massive star in the known universe, only surpassed by its neighbor in the Tarantula Nebula, BAT 9998, whose mass exceeds the sun's by 30 solar masses. But these titles won't last long. Both stars are being stripped by intense stellar winds. For R136A1, these winds reach a mind-boggling 2,600 kilometers per second. Because of this, the star loses over three quintillion kilograms of mass every second. Scientists estimate that since its formation, it has already shed about 35 solar masses. Its luminosity is equally stunning. Almost 4,777,000 times that of our sun. If our sun were this bright, the temperature on Earth would rise to an insane 16,200 kelvins. That's almost three times hotter than the sun's surface. But R136A1 ranks only seventh in the universe in terms of luminosity. The title of the brightest star belongs to Godzilla from the sunburst galaxy. It's brighter than the sun by an unbelievable 255 million times. But R136A1 could easily beat this monster in the race for the hottest star. Its surface temperature reaches around 46,000 kelvins, which is about one and a half times hotter than Godzilla, and almost eight times hotter than the sun. Yet even R136A1 doesn't come close to the champion in this category, the true master of extreme heat. This unassuming star, with a radius half that of the sun, is WR102, and it just might be one of the most dangerous stars in space. Its extreme stellar winds strip off mass hundreds of millions of times faster than the sun sheds its own. These raging winds, along with powerful ultraviolet radiation, compress and ionize the surrounding interstellar matter, forming a bubble-like nebula around the star. All of this is due to the star's scorching temperature, which reaches about 200,000 kelvins If our sun ever got that hot, it wouldn't just boil away the ocean sand atmosphere, it would vaporize most chemical elements on Earth. Scientists suspect that WR102 is nearing the end of its life and could soon explode as a supernova, surrendering its title as the hottest star in the universe. Although R136A1 didn't take the crown in any specific category, its rare combination of mass, brightness, and temperature makes it truly one of a kind. But just like the Guinness World Records, where next to the heaviest weight ever lifted by a human, you'll also find a record for the longest walk on LEGO bricks ever completed, the universe has its own weird champions and underachievers too. If you thought that colossal stars with radii thousands of times larger than the sun's are the most mind-blowing things in space, think again. In fact, being the smallest in the universe is a far greater challenge. But this star, with an extraordinarily long name, EBLM J055557AB, seems to pull it off. Its radius and mass are just 8% that of our sun. It's the smallest star known to humanity, capable of sustaining nuclear fusion in its core. And the wildest part is that it's even smaller than Jupiter. So why hasn't Jupiter turned into a star? Luckily for us, even though this gas giant weighs twice as much as all the other planets in the solar system combined, its mass totals only one thousandth of the sun's mass. And that's not nearly enough to kickstart nuclear fusion. But not all stars play by these rules. For instance, another contender for the longest name, PSRB 094310, might be the most mind-blowing star in the universe. This pulsar, made up of neutrons and an insanely strong magnetic field, rotates around its axis in just 1.1 seconds. The most astonishing part, though, is that the star's radius is only 2.6 kilometers. That's less than four millionths of the sun's radius. Yet, despite being this tiny, the pulsar emits enough radiation to wipe out life on Earth. Unfortunately, this record holder is doomed to a sad fate. It will gradually stop spinning, and its temperature will drop until all that remains is a dead core. But among the cosmic record holders, one marathoner refuses to die. I'm talking about a supernova in the Ursa Major constellation, known as IPTF-14HLS. In 2014, a team of scientists from the University of California, Santa Barbara noticed the explosion of a supernova at over 500 million light-years away from Earth. Initially, it seemed like an ordinary event, until the explosion happened again, and again, and again. Over the next 1,000 days, scientists observed five peaks in brightness, each equivalent to the formation of five different supernovae. What's even more baffling is that when they checked historical data, they found that the star had already exploded exactly 60 years earlier. How could such a thing even be possible? Scientists still don't have a definitive answer. One hypothesis suggests that the star's core may have formed antimatter. Every time this antimatter came into contact with regular matter, it would annihilate, causing an explosion similar to a supernova. Perhaps future discoveries will shed more light on this enigma. But one thing is certain, the more cosmic discoveries we make, the more new records among stars we'll uncover. And one of them might just be the largest Daruma doll in the entire universe. You see, scientists speculate that at the core of some red giants, there might not just be compressed helium, but a full-blown neutron star. Such a Daruma star could form when these two celestial objects collide, for example, in the overcrowded environment of a globular cluster. This hypothesis about the existence of these stars was first introduced back in 1977 by theoretical physicist Kip Thorne and astrophysicist Anna Zitkoff. Then in 2014, the Magellan Clay Telescope in Chile discovered the first potential Thorne-Zitkoff object, a star called HV2112. However, four years later, new research dismissed the presence of a neutron star inside that red giant. The thing is, objects like these would need to contain lithium, molybdenum, and rubidium in high concentrations. However, a fresh look at this candidate failed to find the required levels of these elements. But don't be discouraged. That same year, scientists found a new candidate for the first-ever Daruma star in the universe, HV11417. And once its status is confirmed, we'll have a new entry in our cosmic record book right alongside the brightest dark matter star. In 2023, the James Webb Space Telescope found several candidates for this category. They are JADESGSZ130, 120, and 110. They are so far away that the light we're seeing now was emitted almost 14 billion years ago, just 200,000 years after the Big Bang. And if scientists can prove these are not distant galaxies, but actual stars, it'll be the breakthrough of the millennium. After all, the existence of dark matter is still unproven. According to theory, dark matter stars would have formed from collapsing clouds of hydrogen and helium at the centers of proto-galaxies in the early universe. There, dark matter particles, which also behave as antimatter, would collide, annihilate, and trigger chain reactions in the gas cloud. These processes heated the hydrogen-helium clusters, giving birth to stars. The temperature of a dark matter star could be as high as the sun's, but its mass is a million times greater, and its brightness is a billion times more intense than our sun's. At the end of its life cycle, this kind of star, theoretically, should collapse into a supermassive black hole. For now, scientists need just one more clue to confirm that these three objects are, indeed, dark stars. Scientists need just one more breakthrough in the electromagnetic spectrum, which could come from a specific helium isotope. That isotope would prove to scientists, and to the world, that what we are seeing is truly a dark matter star, not a galaxy. But while the scientific community awaits a breakthrough, the universe may see the emergence of a new class of record holders, black dwarfs. They represent the final evolutionary stage for stars like our sun. The only reason black dwarfs don't exist yet is that the universe is still too young. When the nuclear reactions inside the sun stop, and it sheds its outer layers to form a nebula, all that will remain is a white dwarf, small, incredibly dense star with a temperature of between 4,000 and 150,000 kelvins. But because this star would be dead inside, it can no longer maintain that temperature, so the former sun will slowly cool down until it becomes a black dwarf, a dense, cold, dark sphere. However, this transformation will take about one quadrillion years, and our universe is only about 14 billion years old. That's why black dwarfs just don't exist yet. But in the distant future, these stars might compete for records in several categories. Besides their extreme density, which could even trigger explosions and cause some massive black dwarfs to turn into supernovae, they might also earn the title of coldest stars. Their surface temperature could hypothetically drop to just shy of absolute zero. No star has ever set such records before, but considering everything I've told you in this video, which star is the ultimate record holder? I won't keep you in suspense any longer. The title of the universe's greatest record holder goes to the star we see most often in the sky, the sun. Even though it's far from the largest, or the most massive, or even the strangest object in space, the sun is the only known star around which life has emerged. Life intelligent enough to evaluate other stars and hand out imaginary cosmic records. So who would you crown the ultimate champion of the stars?