10 ms·
'Ultramassive' black hole discovered – bigger than the majority of galaxies
- rwaksmunski 4y ago30 billion solar masses, numbers kind of loose the meaning at this scale.
- unnouinceput 4y agoNot masses, size. The article says size.
- nathan_compton 4y agoIn the case of a black hole mass and size (radius) are inextricably and linearly linked. All black holes with a given mass have the same radius (modulo a small effect of angular momentum).
- davorak 4y agoI did a rough calc in: https://news.ycombinator.com/item?id=35361280 https://news.ycombinator.com/item?id=35361280 When it was pointed out TON618 has ~66 billion solar masses. But if it is 30 billion times the size of the sun then I think that means it is ~2354000 billion solar masses.
- runnerup 4y agoI believe for black holes the volumetric size is a known function of mass. If you exclude the rest of any Lyman-alpha blob present around the black hole.
- trilbyglens 4y agoMass is the only really meaningful measure of a blackhole, as they occupy a spacial singularity, which is to say, the have no measurable size. The event horizon has a diameter, but that's not the object itself.
- ioblomov 4y agoGuessing that "size" for black holes can mean mass, volume, or radius. But I'm pretty sure the relationship between those three quantities is well defined and directly proportional, so any way you look at it, this thing is incomprehensibly huge.
- croes 4y ago30B time the mass of the sun is already huge but 30B times the size of the sun would be much much bigger.
- javajosh 4y agoIt is not possible to have an intuition about 1 solar mass, by easily 10 OOM. Adding OOM can't make it less comprehensible.
- seanhunter 4y agoIf they want people to relate to their numbers, they have to use units people understand, and also they need to be accurate about which dimension they are talking about. If it's mass the correct popular science dumb reporting unit is the blue whale. Ie "The mass of this black hole is almost 3 x 10^35 blue whales" If it's size, the correct popular science dumb reporting unit is the football field unless it's specifically length, in which case it's acceptable to either go with football field or switch to double-decker bus or blue whale.
- galaxytachyon 4y agoWell, most people can't properly understand the scientific notation, as in getting a proper scale of how big one order of magnitude is supposed to be. They may see ^35 and say "oh, so it is like less than 100 of something, meh". If you doubt that, remember the quarter pounder ads where they made people think 1/4 is kinda more than 1/2 because 4>2...
- seanhunter 4y agoThe point is how are people ever going to get intuition about the numbers if they don't report them in blue whales/football pitches/double decker busses?
- samus 4y agoAt these scales, it really doesn't make much of a difference, as a sibling commenter pointed out.
- seanhunter 4y agoI was being sarcastic. Pretty sure it's impossible for the vast majority of people (myself definitely included) to gain any kind of intuition for numbers of this scale. I also don't gain any intuition for things by comparing them to a blue whale etc (and I'm not really sure anyone else does either) and find it pretty weird that it seems to be a go-to comparison for science articles in the press.
- jws 4y agoA billion is three groups of three zeroes. So for visualizing I would think of a cubic meter compared to a cubic millimeter. A grain of sand serves for a cubic millimeter. For the cubic meter you can either visualize a cube that size, or four oil drums, or a small hot tub. Now for the 30 out front, That’s about 27 which is 3^3 so let’s just size a smaller grain of sand which is only 1/3mm on a side. Maybe table salt would be good. So a grain of table salt in a small hot tub. If you perform this thought experiment with actual solar masses, use sufficiently long tongs and wear eye protection.
- lttlrck 4y agoThat's really neat. Thank you.
- boringg 4y agoCan anyone confirm the accuracy here? Sounds rather significant however I don't know the theoretical limit of how big a black hole can be - or the implications of that (haven't considered it). Seems like we are in an era of discovery in space - heady times!
- ravi-delia 4y agoThere's no real limit, since you can just keep dumping stuff in forever. There is however a soft limit that the stuff has to be close enough to get dumped in, and this one is extremely old so we aren't sure where it got its mass from!
- taylodl 4y agoAu contraire! There's plenty of mass to feed such a black hole, the real question is "when you run things backward" in the lambda-CDM model why isn't the entire universe a black hole? Or why wouldn't it be the case that there wasn't a primordial mega star that quickly (in universal time) collapsed into a supermassive black hole and the remnants of the supernova is the mass of the remainder of the universe and form the CMB radiation?
- michannne 4y agoThis is a cool idea I've never heard before. The universe we're in is the result of a cosmically massive star going supernova.
- xenadu02 4y agoI don't know the number but the limit is the speed of light and expansion of the universe. In the modern phase of the universe a black hole would only be able to eat its own galactic cluster (or maybe supercluster). Hubble expansion means superclusters experience the expansion of spacetime so certainly any matter beyond a black hole's own supercluster will move away from the black hole faster than light and thus never be able to fall into it. In practice a black hole can't even get near that limit because angular momentum can't just vanish... much of the matter would (over a long time) end up in distant orbit around that super super massive black hole and never fall into it. In the early universe spacetime expansion was happening so quickly that it was difficult for large black holes to form at all. If that were not the case most matter in our universe would have collapsed due to gravity and ended up in black holes but we know it did not. Actually if gravity were that strong or expansion were slower/weaker then the universe would never have formed at all and stayed as a singularity. To get formation of super large black holes very early you'd need a knife-blade balancing act of gravity vs expansion to just barely form super super massive black holes without the "permanent singularity, no universe" scenario. We can see billions of stars, galaxies, etc so we know that scenario did not happen. Super super massive black holes are neat objects though. If this one really is as big as they say then it will be one of the last objects left in the universe. It would take trillions and trillions of years for it to evaporate due to Hawking radiation. I wonder if the last life left in the universe will end up gathered around this black hole, surviving on the Hawking Radiation energy gradient?
- iameli 4y agoThe use of the term "bigger" here is frustrating. Mass or volume?
- jmyeet 4y agoBlack hole volume is entirely a function of mass.
- philipov 4y agoBlack holes don't have a volume, they only have a surface area, and it depends strictly on their mass.
- ravi-delia 4y agoAnd spin/charge, no?
- nathan_compton 4y agoThis isn't true at least in the case of the ordinary black hole solutions in general relativity. These solutions tend to be valid throughout the volume of the black hole (except at the singularity, which takes on different shapes depending on spin or charge but doesn't occupy the whole interior volume of the black hole if you think of the event horizon as bounding the volume).
- tyfon 4y agoI thought they were valid throughout the volume/radius, but that the solution only gives you the surface area for that radius, not the volume. Perhaps I have misunderstood though as I am just a hobbyist :)
- nathan_compton 4y agoThe volume inside the event horizon isn't what you would expect if you consider the black hole as a sphere with its external area, but it has a volume. It might be the case that in quantum gravity there isn't an interior, but in GR the idea of the volume is a little weird, but not problematic.
- PaulHoule 4y agoThe puzzle here is that astronomers have no clear picture of how these ultra massive black holes are formed so early in the evolution of the universe. if you wait long enough galactic black holes can eat stars, gas, and other black holes, but there was no time for that early on. It is conjectured there were huge ‘Population III’ stars that grew rapidly because radiation transport was different when there were tiny amounts of elements heavier than helium (‘metals’ in astronomer lingo.) Pop III stars are a bit less mysterious than dark matter but they could have played important roles in the early universe.
- Arwill 4y agoThe hypothesis is that these black holes were not created from stars, but exists from right after the big bang. https://en.wikipedia.org/wiki/Primordial_black_hole https://en.wikipedia.org/wiki/Primordial_black_hole
- PaulHoule 4y agoOne of the hypotheses. Pop III stars could have gotten pretty big but probably not as big as that one. Hopefully JWST will turn up some direct evidence for them.
- chongli 4y agoYeah, the issue is that when large amounts of matter gathers into the accretion disk of a black hole it creates more and more friction as it falls in. This friction generates a lot of heat (and therefore pressure) which pushes back on the in-falling matter, slowing down the accretion process. If there's an overwhelming amount of matter the accretion will disk will get so jammed up and energetic the black hole will start firing off high-energy relativistic jets from its poles. If you start with a stellar black hole of say 10 solar masses and then throw millions of solar masses of material at it, the above processes will slow things down dramatically, and you won't be able to get a supermassive black hole instantly.
- s0ph0n 4y agowhat if those old giant blackholes were created by all the missing antimatter that we dont see in the CMBR.
- jmyeet 4y agoIt's worth noting that there is a limit to how fast black holes can grow [1] so ultra-massive black holes like this tell a story, namely: 1. It starts placing limits on how young the black hole can be. IIRC black holes like this must've been formed very early in the Universe, which may be earlier than our models otherwise predict, suggest or even say is "possible"; and 2. It is theorized (again, IIRC) that a lot of ultra-massive black holes such as those at the center of many if not most galaxies can only really form by the merger of black holes due to the above limits. These must be unbelievably energetic events. It's possible that such events may actually star formation in nearby nebulae. [1]: https://physics.stackexchange.com/questions/167250/is-there-a-limit-as-to-how-fast-a-black-hole-can-grow https://physics.stackexchange.com/questions/167250/is-there-...
- ftxbro 4y ago[flagged]
- lwansbrough 4y agoGuys please don't deploy LLM bots on HN...
- Shared404 4y agos/ on HN// But also here, yes.
- ftxbro 4y agoI'm not an LLM I was nitpicking the grammar of the BBC caption that is confusing and makes it like a "garden path" sentence like the example I put. Sorry for nitpicking tho, even tho it is the BBC and the article was so short. https://en.wikipedia.org/wiki/Garden-path_sentence https://en.wikipedia.org/wiki/Garden-path_sentence
- leephillips 4y agoEven with its mistake I found the caption easily parseable, and whatever you thought you were doing just annoying.
- antibasilisk 4y agolooks more like a markov chain
- techwiz137 4y agoSo then why is TON618 at 66 billion solar masses? https://en.wikipedia.org/wiki/TON_618 https://en.wikipedia.org/wiki/TON_618
- davorak 4y agoedit the bbc article got it wrong withe 30 billion times the size and it supposed to be 30 billion solar masses see [1] or the arxiv article [2] The bbc article says 30 billion times the size while TON618 is 66 billion times the mass. Wikipedia says TON618 has a Schwarzschild radius of 1,300 AU (390 billion km in diameter) vs teh sun's 1.3927 million km diameter. Which makes TON618 ~280k bigger than the sun. So if my math is right that makes the Ultramassive balck hole in the bbc article ~107k larger than TON618. edit give the R = 3M relation for black holes twice the radius means twice the mass. So 107K times the radius means 107k times the mass. The Ultramassive balck hole in the bbc article would have ~2354000 billion solar masses. edit give the above I want to fact check BBC's 30 billion times the size vs 30 billion solar masses since the later seems more reasonable. edit 30 billion solar masses is what is given directly by durham and arxiv[2] [1] https://www.durham.ac.uk/news-events/latest-news/2023/03/light-bending-gravity-reveals-one-of-the-biggest-black-holes-ever-found--/ https://www.durham.ac.uk/news-events/latest-news/2023/03/lig... [2] https://arxiv.org/abs/2303.15514 https://arxiv.org/abs/2303.15514
- wumms 4y agoMy understanding of the abstract is (I'm not an astronomer): TON 618 is an active SMBH ("hyperluminous, broad-absorption-line, radio-loud quasar" [0]). The SMBH they found has a smaller mass [2], but it is passive (= much darker). From the abstract: "Outside the local Universe, measurements of MBH are usually only possible for SMBHs in an active state: limiting sample size and introducing selection biases. Gravitational lensing makes it possible to measure the mass of non-active SMBHs." [1] [0] https://en.wikipedia.org/wiki/TON_618 https://en.wikipedia.org/wiki/TON_618 [1] https://academic.oup.com/mnras/article-abstract/521/3/3298/7085506 https://academic.oup.com/mnras/article-abstract/521/3/3298/7... [2] "it could be a supermassive black hole equivalent to 13 billion suns: 1.3±0.6)×10^10 M" https://en.wikipedia.org/wiki/Abell_1201_BCG https://en.wikipedia.org/wiki/Abell_1201_BCG
- 4y ago
- artursapek 4y agoIf a black hole is just constantly eating up surrounding matter and growing, why haven't we gotten sucked up by one yet?
- sdfghswe 4y agoBecause space is very big.
- trilbyglens 4y agobecause space is facking huge.
- prottog 4y agoEstimates are an average of six protons per cubic meter of space. A whole lot of nothing!
- daveslash 4y ago"Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."
- phailhaus 4y agoBlack holes don't "suck", they have gravity like anything else. If you replaced the Sun with a black hole of the same mass, all the planets would continue in their orbits.
- Rooster61 4y agoI'd imagine there would be at least some deviance from their current orbits. The sun experiences tidal forces, just like any other body, and the distance between each planet and the closest/furthest atoms of the black hole would be different than that of the sun. Not sure how much different the orbits would be, but they would certainly be different to some degree.
- raydiatian 4y agoFor those wondering, the radius of this black hole (assuming a Milkyway’s worth of mass), based on the Schwarzschild radius, would be anywhere from 10-1000x larger than Sagittarius A, the supermassive blackhole at the center of the Milky Way. I don’t think the article stated this.
- awb 4y agoI think it’s about 7,500x. This one estimated to be 30B solar masses. Sag A is estimated at 4M solar masses.
- raydiatian 4y agoNice, that's probably closer then. I just plugged in the mass of the milky way for the mass.
- dack 4y agoI can't tell how certain we are of its size - it's so big that it makes me wonder whether the easiest explanation is that our methods were incorrect. For example, if we are measuring how light bends - how do we know there aren't many hidden (i.e. not large or bright enough to be noticed from earth) objects causing additional distortion and therefore throwing off our measurements? Do we also observe it over time to get more confidence, or have some other cross-checks that give us more certainty? Either way, every once in a while I find it wild just how much we can deduce about the universe from our tiny fixed vantage point.
- killingtime74 4y agoDon't know the answer to your questions but we are not at a fixed vantage point
- vitiral 4y agoFixed relative to other galaxies...
- naikrovek 4y agowe move on Earth as the planet rotates, Earth moves within its orbit in the Solar system, our Solar system moves within its orbit in the galaxy, and our galaxy moves (we believe) within the universe, though I don't think we know how fast or what direction; generally, everything outside our local group is moving away, though.
- datavirtue 4y agoOur sun moves around the galaxy at about 500,000 mph...and thus so do we.
- acapybara 4y agoThe things aren't moving apart. Space itself is expanding.
- hpb42 4y agoThe article is about the Abell 1201 black hole. The paper referenced in the article is paywalled though[0]. And Wikipedia has a List of most massive black holes[1]. Quite fascinating, although the list is about their masses and not their sizes. I'm not an expert on the subject, but the Abell 1201 black hole and the others in the list are near the theoretical limit of a black hole's mass (5 * 10^10 solar masses). [0] https://academic.oup.com/mnras/article-abstract/521/3/3298/7085506?redirectedFrom=fulltext&login=false https://academic.oup.com/mnras/article-abstract/521/3/3298/7... [1] https://en.wikipedia.org/wiki/List_of_most_massive_black_holes https://en.wikipedia.org/wiki/List_of_most_massive_black_hol...
- croutonwagon 4y agoHere is a copy of the paper https://arxiv.org/pdf/2303.15514.pdf https://arxiv.org/pdf/2303.15514.pdf
- lcnPylGDnU4H9OF 4y ago> their masses and not their sizes Do black holes even differ in density? I would have thought all black holes have a constant and consistent density but I don't think I've ever really considered it before.
- sclarisse 4y agoThey do! Or at least, the volume bounded by the event horizon has variable density. The small ones are much denser, and the large ones are much less dense. (Whatever the degenerate matter at the center is like, that’s another matter.)
- Iwan-Zotow 4y agoSure. Supergiant BHs are less dense than water
- sclarisse 4y agoThe size of a black hole’s event horizon is pretty much directly correlated to its mass; I think the only thing that really modifies it in practice is very fast rotation. (Remember, it’s a phenomenon of gravity, not a physical object. The physical stuff inside is just some really intense matter squeezed together in ways that might be interesting, if they were observable.)
- sacnoradhq 4y ago0. Seems there are a half dozen other SMBHs also close to the theoretical limit. What's novel about this discovery? 1. Is the Great Attractor a SMBH > 1e10 M(.)?
- bashinator 4y agoThe Great Attractor is likely a cluster of galaxies with lots and lots of SMBHs.
- sacnoradhq 4y agoI wonder about inflation vs. gravity of these massive structures. "Locally" in the supercluster scale, I'm wondering to what degree gravity swamps dark energy inflation.
- tyfon 4y agoI think the novelty here is the way of discovery, at least that is how I read the paper.
- sacnoradhq 4y agoAh thanks for the elucidation. I'm too ignorant in this subject area to compare or contrast this paper with the corpus of literature from any point of expertise or reference.
- Drblessing 4y ago[flagged]