There's nothing like looking at the night sky to make you feel small. But when you look at the cosmos, you can also ask yourself, what is the most massively known object in the universe?
In a sense, the question depends on the meaning of the word "object". Astronomers have observed structures like the Great Wall of Hercules-Corona borealis-a colossal filament of gas, dust and dark matter containing billions of galaxies that extend for about 10 billion light-years long-which could compete for Title of the greatest object of all time. But sorting this assembly as a single object is problematic because it's hard to figure out exactly where it starts and ends. "Object" actually has a clear definition in physics or astrophysics, said Scott Chapman, astrophysicist at the Dalhousie University in Halifax, in the Canadian province of Nova Scotia. "This is something connected by its own gravity," he said, like a planet, star or the stars orbiting within a single galaxy. With that in mind, it's a little easier to figure out what's running for the most massive thing in the universe. The award could go to different entities depending on the scale being considered, but each award-winning gave scientists insight into the limits of size and mass in the cosmos.
Largest planet, cluster of stars and galaxies
For our relatively small species, the planet Earth is very large, with about 13 billion pounds. (6 trillion pounds)-or 13 with 24 zeroes later. But it is not even the largest planet in the solar system, being surpassed by the external giants, Neptune, Uranus, Saturn and the mighty Jupiter, which weighs 4.2 million pounds. (1.9 octillion kg), or 4.2 with 27 zeros later. Researchers have discovered thousands of planets orbiting other stars, including many that make our local giants seem insignificant. Discovered in 2016, the HR2562 B is the heaviest exoplanet found so far, with a mass 30 times greater than that of Jupiter. At that size, astronomers are not sure if they classify the giant as a brown dwarf, which would make it a kind of little star instead of a planet. The stars themselves can grow in huge sizes, with the most massive star known, R136A1, being something between 265 and 315 times heavier than our sun, which is unmatched 4.4 billion pounds. (2 nonillion kg), or 4.4 with 30 zeros later. Located 130,000 light-years away in the Great Magellanic Cloud, a companion galaxy orbiting our Milky Way, the R136A1 is so big and bright that the light it emits is actually destroying it., according to a study of 2010 in the Monthly Notices of Ro Yal Astronomical Society. The electromagnetic radiation flowing from the star is powerful enough to carry the material from the surface, causing the star to lose about 16 times the mass of the Earth each year. Astronomers don't know exactly how this self star can form and how long it will hold.
The galaxies are the next objects up to the size scale of the cosmos. The Milky Way galaxy is already massively expansive, extending for 100,000 light-years from end to end, containing approximately 200 billion stars, and weighing about 1.7 trillion times the mass of our sun. But it can't compete with the central galaxy of the Phoenix Cluster, a 2.2 million-light-years-old leviathan that contains about 3 trillion stars, according to NASA… In the center of this animal there is a supermassive black hole-the largest ever seen-with an estimated mass in 20 billion suns. The Phoenix Cluster is a massive accumulation of approximately 1,000 galaxies, all orbiting about 5.7 billion light-years away, with a total mass of about 2 quadrillion of Suns, which is 2 with 15 zeros later, according to a 2012 article from the magazine. Nature. But even this Goliath cannot compete with what is probably the most massive object ever seen–a newly discovered galactic protocluster known as SPT2349, which was described on April 25 in Nature Magazine. "We hit the jackpot with this structure," Chapman, whose team discovered the record, told Live Science. "Over 14 very massive individual galaxies have swarmed into the space of something not much bigger than the Milky Way." Detected when the universe was only one-tenth of its current age, the individual galaxies in this grouping will eventually combine into a gigantic galaxy, the most massive of the universe. And it's just the tip of the iceberg, Chapman said. Other observations have revealed that the total structure contains about 50 additional galaxies that will settle into an object known as a galactic cluster, in which many galaxies orbit each other. The previous most massive recordist, the aptly named El Gordo Cluster, weighs the equivalent of 3 quadrillion (or 3 with 15 zeros after it) Suns, but the SPT2349 probably surpasses at least four to five times. That such an enormous object could form when the universe was only 1.4 billion years was surprising to researchers, since computational simulations suggested that it would normally take much longer for such large objects to appear . "The massive central galaxy forms incredibly early and much more explosive and quickly than we could have imagined," Chapman said. "Just the twinkling of the eyes on the cosmic scales." Given that humans have sought only a fraction of the sky for such things, even more massive objects may be hidden in the universe, he added. Editor's note: This story has been updated to correct the name of the huge cluster of galaxies that is the largest known object. It's SPT2349, not dusty Red Core. Originally published in Live Science.