Astroboffins peering back in time with Hubble find stars may have been flickering into life even earlier than thought

European astronomers, using data from the veteran Hubble Space Telescope, have suggested the formation of the first stars and galaxies in the early universe happened earlier than thought. The NASA and ESA space telescope is capable of peering back into the early history of the universe and, with the aid of advanced boffinry, …

[Anonymous Coward]

We're special

Our universe is special? All of time and space were made specially for us in a single creation event? Nah that's religion.

Find a shrinking black hole ejecting a spiral galaxy as it turns. The young stars will be near the middle the older stars near the outer edge. You'll find raw matter (quarks and light and monopoles) at the very edge of the event horizon. All of this would be impossible, and yet it will be there. Ask yourself "how can it be ejecting anything"?, "how is it shrinking"?, "how can all this stuff be at the event horizon when it is not sucking stuff in"? You'll be in disbelief.

As the stuff comes out of the black hole, there will be more field lines per resonant-oscillation in this (outer) universe and more apparent 'space' in our universe, the galaxies will be pushed apart. The expansion you attribute to 'big bang'.

Inside the black hole is a universe, like ours, we are also in a black hole. You should already with your existing (stretched space) models be able to predict black holes inside black holes. Can you?

[Anonymous Coward]

Re: We're special

[1]@"You should already with your existing (stretched space) models be able to predict black holes inside black holes. Can you?"

Can you also find this observation:

[2]Matter pulls on matter strongly, Black holes pull on black holes strongly, *but* backholes pull on matter far weaker than expected. As if blackhole to matter gravity is somehow weaker than matter to matter gravity.

Now you can put the two together, take the matter inside a blackhole B1, place half of it inside a black hole B2 that itself is inside black hole B1. Now B1s pull is even weaker, and so its event horizon shrinks. As it shrinks its pull on the matter around it reduces, and some matter escapes.

So you now understand the mechanism by which blackholes shrink. Simply by modelling [1] and observing instances of [2].

Both of these should be possible today to find.

[KittenHuffer]

Re: We're special

You are not even wrong - Wolfgang Pauli

[bombastic bob]

Re: We're special

interesting theory, any 'sauce' to back that one up? A link or two into some research documents might be fun to look at.

Truly we don't really know what happened at (and just after) 'the big bang', and can only guess based on our CURRENT understanding of science, which of course is a moving target as we learn more and tweek our understanding based on the evidence. [not to say our guesses aren't pretty good]

That being said, my guess is _ALSO_ that the 'primordial' stars that are supposed to only have H, He, and Li in them, may be a bad assumption. Because Fe and Ni and Co have the highest binding energy per nucleon, there is still a high likelihood [in my bombastic opinion] that the presence of elements "through Xenon" is STILL likely, even in the "furthest back in time" stars, even those most likely formed right after the big bang. [but I'd expect concentrations to be low, yet not "missing"]

This is because fusion reactions that form these elements are all exothermic. In the presence of sufficient gravity and the hydrogen-hydrogen fusion reaction, you'll quickly see the buildup of elements through Fe, and over time, maybe even through Xenon.

But for the heavier elements, above Fe/Ni/Co on the periodic table, I would expect VERY low concentrations of them as compared to more recently born stars. And probably lower concentrations of the other elements as well, at least as compared to our Sun [this last part has apparently been observed, at least from what I saw in the article].

[I'd still be just as happy if I'm wrong, though, because that's science]

there's a nice wikipedia page that explains the whole binding energy thing, with a chart showing where Fe is on it, right at the top.

https://en.wikipedia.org/wiki/Nuclear_binding_energy

So I'd have to wonder, how long would a star need to be fusing pure hydrogen (or H+He+Li) before it starts to form a detectable level of Fe/Ni/Co???

[Anonymous Coward]

Re: We're special

That being said, my guess is _ALSO_ that the 'primordial' stars that are supposed to only have H, He, and Li in them, may be a bad assumption. Because Fe and Ni and Co have the highest binding energy per nucleon, there is still a high likelihood [in my bombastic opinion] that the presence of elements "through Xenon" is STILL likely, even in the "furthest back in time" stars, even those most likely formed right after the big bang. [but I'd expect concentrations to be low, yet not "missing"]

It's not clear from this whether you are claiming that big-bang neucleosynthesis will produce heavier elements than Li, which would be very unexpected, or whether the earliest stars would synthesize such elements, which would be expected.

Assuming you mean the second thing, then yes, they do of course synthesize heavier elements: stellar nucleosynthesis is presumed to be largely how those elements got here. But stars don't synthesize heavier elements until until very late in their lives: for most of their life they're happily burning H to He. So if we observe first-generation stars (ie Pop III stars) significantly before the ends of their lives then they'll have very low metallicities indeed, because all they'll have is the stuff they inherited from BBN, which, by assumption, does not include anything (or much?) heavier than Li, and the stuff they've created up to then which will not include many heavy elements.

And if you sample a bunch of Pop III stars then statistically you expect to see most of them at times well before the ends of their lives.

But of course we haven't seen any yet.

[bombastic bob]

Re: We're special

"And if you sample a bunch of Pop III stars then statistically you expect to see most of them at times well before the ends of their lives."

"But of course we haven't seen any yet."

I was calling into question whether or not we'd EVER see them if the definition is "only H, He, and Li". I'm suggesting that it wouldn't take long at all for stars to produce elements through Fe/Ni/Co VERY quickly, and possibly other, heavier, elements. If I'm correct, and the earliest stars were mostly super-massive super-bright stars that quickly burned out AND went supernova in a relatively short period of time, you'd see very very few examples of a star with ONLY H, He, and Li in it...

[so one 'big bang' followed by a lot of 'smaller booms' of rapidly burning out massive stars going supernova a LOT, until things stabilize]

One theory of H fusion inside of stars requires the presence of Carbon to work properly. If this is correct, the lack of carbon might get you a VERY unstable star, requiring much higher mass etc. etc. etc.. I should do some personal research on that one, for grins, to see if that theory has changed or been debunked. [in the theory C + H -> N + H -> O + H -> F + H -> He + C so carbon is consumed, then re-created at the end - and the slower reaction cycle would stabilize the star]

As for big bang, we really don't know what really happened, and that was my point, too. We assume only H, and maybe He and Li [both common fusion products from pure H fusion), but this science could be wrong and something we don't currently understand might become known and explain it all... so who knows!

(If we could make a big bang in a lab, or with a mega-collider, these questions would be answered, but I don't know of any way to experiment with the actual event in question so we're stuck guessing)

[Anonymous Coward]

Re: We're special

I think you're right about lifetimes, Pop III stars are expected to be very massive and to have very short lives, and I think the idea is that this is due to lack of carbon.

But if we assume that the big-bang didn't produce anything much heavier than Li (see another comment of mine in reply to someone else on why this is plausible) then we can, I guess, work out based on more recent element abundances how many Pop III stars there must have been. And I'm guessing the answer is 'a lot', so even though they didn't last long there ought to be a lot to see. And as you look back further and further you kind of can't avoid seeing them at some point, even if they didn't last for long.

But obviously I'm not saying 'this must be the case': if what we think is true is true then it should be the case, but if it's not true then something else may be the case, and that would be very cool. And these people have been looking for where I think they expected to be able to see them and haven't, so who knows? As I seem to repeat in almost every comment: this is a golden age for astronomy and astrophysics.

[Denarius]

Re: We're special

A follower of Arp then ? Fine, but still sound a bit confused. Sure you read his papers correctly ?

[Chris G]

"Inside the black hole is a universe, like ours, we are also in a black hole."

Okay! I have just finished my dinner and have nothing else to do.

So you know this how? Papers, citations? Alternatively, I'll have some of whatever you have been taking, I'm out of wine.

[Anonymous Coward]

Citation

Men In Black

[A. Coatsworth]

It is based on the works of Farnsworth, H. J. He propossed a similar model, with boxes instead of black holes, back in 3003, which ended in a huge paradox.

[Doctor Syntax]

Not finding a trace of Population III objects in the 500 million to 1 billion year period after the "Big Bang" is surprising

It sounds like a good time to be an astrophysicist or cosmologist. "That's odd" is one of the best reactions to have in science.

[jvf]

seems backwards

How come the earliest start are labeled PIII and not PI?

[KarMann]

Re: seems backwards

I've pondered that before, and without having gotten around to looking up a definitive answer, I figure it's likely because the nearer stars, which we examined first, were the newer ones around here, so when we started finding other populations, they became Population Ⅰ, and the rest followed from there. Now, let's see how I scored…

Not quite. It looks like the designation of Ⅰ & Ⅱ in 1944 was quite arbitrary, Ⅰ being the youngest, most metallic (in the astronomical anything-heavier-than-helium sense) stars, and Ⅱ the older, less metallic ones. Ⅲ wasn't named until 1978, and I guess it was just luck that they could expand in the even-less-metallic direction without trying to zero-index Roman numerals. I'll give myself half marks, then.

[Anonymous Coward]

Re: seems backwards

I think also there's the problem that we may not have known how many populations there were. So if people had said 'OK, let's call the earliest stars Pop I', then they might have ended up in the awkward situation of discovering that 'oh no, there's an extra generation, so we need to renumber almost all the stars we see from III to IV', rather than 'we'll have to renumber a small number of stars which we can only just see from III to IV'.

Whether anyone actually thought like that or whether it's just a happy coincidence I don't know, but I suspect happy coincidence.

[ThatOne]

Re: seems backwards

> awkward situation of discovering that 'oh no, there's an extra generation

If it's based on metallicity, there is an obvious starting point, stars containing only and exclusively hydrogen and helium. Since there is no way you can find something with even less heavier elements, they could be the starting point, or "Population I".

Unfortunately the "Population" classification was initially not tied to metallicity and is now askew...

[Anonymous Coward]

Re: seems backwards

If it's based on metallicity, there is an obvious starting point, stars containing only and exclusively hydrogen and helium. Since there is no way you can find something with even less heavier elements, they could be the starting point, or "Population I".

Yes, and that leaves you precisely in the awkward solution I described: which population does the Sun, and almost all stars we see, belong to? One day it's III and then, suddenly it's IV (or II!). Whereas if you go backwards you never need to do that: it's always I.

(Not that I think this is how the naming happened, but it's kind of convenient now it has.)

[ThatOne]

Re: seems backwards

> which population does the Sun, and almost all stars we see, belong to? One day it's III and then, suddenly it's IV (or II!).

Why? IMHO it's like with tornadoes (or hurricanes), you start your scale at 0 (no wind) since that's necessarily a dead end, a start, and from there count up by increments. There is no reason you might one day need to insert a tornado force between 2 and 3, but since we don't really know how strong they can get, it's good the scale is open-ended. It finishes at 5 right now, but we might one day need to add category 6 tornadoes (or hurricanes).

As for the Population naming, AFAIK it was initially based on where in the galactic disk specific stars were most abundant (spiral arms, halo, etc.). It initially had nothing to do with metallicity, it's only after naming them they discovered that the stars in the Galaxy's spiral arms (like our sun, which they had named Population I) were younger than the stars in the halo (named Population II), and inferred that there must necessarily exist a type of star even older (which would have to be named Population III).

[Cuddles]

Re: seems backwards

"How come the earliest start are labeled PIII and not PI?"

Because back when the difference was first noticed no-one had any idea why they were different. The classification of the two populations came about because of spetroscopic measurements done around the 1920s, which noticed that stars could mostly be grouped into those that have lots of metals in them and those that don't. These observations were done around the same time as observations indicating that the universe might be expanding, and other observations suggesting that some nebulae might actually be outside our galaxy and could potentially be entire galaxies themselves. The 1910s-1920s were a pretty big time for cosmology.

But obviously, without even knowing that other galaxies existed or that the universe was expanding, let alone how big or old it might be, there wasn't any way to figure out that the different stellar populations were due to the time of their formation. So they were pretty much arbitrarily labelled I and II, and it just happened to turn out that it would later appear more sensible if it had been the other way around. Population III were only added much later, and simply followed on the already established trend.

See also something like electron charge being negative, which was again essentially a 50/50 guess at which direction the charge-carrying particles might be moving when an electric current flows, made before we managed to figure out the actual details.

[HelpfulJohn]

Re: seems backwards

"How come the earliest start are labeled PIII and not PI?"

We thought all stars were like Sol and friends, the ones near us that we can take spectroscopy of quite easily. About a century ago, we found out that stars in Globular Clusters and the cores of what were then called "Spiral Nebulae" are systematically different from Sol-type stars so we then had "Population One" stars like Sol, Rigel, Sirius and the others in the spiral arms of what came to be seen as galaxies and "Population Two" stars that were identifiably different.

At the time, we had no idea what the reason for the differences was all we knew was that the stars near Sol and in the spiral arms of those Nebulae were of one sort and the stars in cores and clusters were of another.

As our Sol is *our* star and as its kind were discovered first, calling them Pop. I seemed sensible. The other lot, core and cluster stars were a *second* Population of stars.

It made sense at the time. It still sort of does. And, no, there will never be a need for a "Pop. Minus Five" when really, really new stars are born in milliards of years from now with exceedingly metal-rich bodies. Those will still just be Population I, like Sol.

So, Pop I: new, young, metal-rich stars, mostly in spiral arms. Pop II : older, metal-poor starts in galactic cores and Globular Clusters. Pop III: primordial stars, almost all hydrogen, helium and a smear of lithium; we have no idea where those will show up, not yet. Theoretically, Pop IV stars: born in the really promordial murk from fluctuations in the opaque chaos before the universe went transparent, not really "stars", more like very large bombs. Pop. IV stars would be extremely metal-poor, too and would help to seed the cosmos with heavier elements when they blew up. They might also produce shockwaves in the medium to initiate the condensation of galaxies, galactic super-massive singularities and Pop III stars.

Pop IV stars are, of course, simply my conjecture, there is no actual Science behind them.

There could be Pop. V stars; stars made from stuff that existed before protons, that fuelled a Civilisation in the very first instants after the Cosmic Expansion and that created ripples in spacetime which allowed for galactic superclusters to form but those are truly SF.

[STOP_FORTH]

Telescope nomenclature

We really need a Super Duper Telescope if we are to make any progress in our endeavour to understand the Universe.

[bombastic bob]

Re: Telescope nomenclature

Super Duper Telescope.

let's do it. I like science!

We could build a nice orbital space station first, assemble the entire thing in space, and send it out to one of the lagrangian points so it can be away from earth-glow and moon-glow.

Also a telescope mounted on the moon might be a really cool thing, too.

[Anonymous Coward]

Re: Telescope nomenclature

You mean, like the JWST, which will sit at the Earth-Sun L2 Lagrange point?

[HelpfulJohn]

Re: Telescope nomenclature

"You mean, like the JWST, which will sit at the Earth-Sun L2 Lagrange point?"

No, it won't. JWST is yet another example of "power too cheap to metre", flying personal vehicles, household robotic servants, Lunar bases, cities in orbit and a whole raft of other stuff that will never happen.

It's vaporware. Sure, there might be a practical model of it sitting in a hangar somewhere but it is going to fly right after the thirteenth human walks on the Moon.

[Anonymous Coward]

Re: Telescope nomenclature

I have no idea on whether it will fly – I think it will, and you're not going to persuade me it won't, but my opinion is worth what you paid for it. The point I was making was merely that ii/when it flies it will sit at Earth-Sun-L2: in other words the idea suggested by the person I was replying to was not some new thing no-one had thought of but rather something for which flight hardware exists.

[STOP_FORTH]

Unhelpful sugestion

Or, just maybe, there never were any Population III stars and loads of "metallic" elements came spewing out of the Big Bang?

[KittenHuffer]

Re: Unhelpful sugestion

That would actually be quite interesting if it is true, as our current understanding of physics is that it would not have been the case. It would mean that there is something new for us to learn.

IIRC currently we believe that by the time (almost) all of the anti-matter had been eliminated, and the energy level had dropped far enough for an atomic nucleus to form, that the density/pressure had dropped to a level that Hydrogen (and a little Helium and Lithium) would be the only atoms to form.

It was only in the heart of the Population III stars that the density/pressure rose high enough to start making heavier elements.

As I say it would be quite interesting as it would require new physics, but is probably very unlikely for the same reason.

[Denarius]

Re: Unhelpful sugestion

Also, no mechanism for Pop 3 starts to form. Simply assuming cooling gas does not work, much as most theorists want it to

[Anonymous Coward]

Re: Unhelpful sugestion

They form the same way all other stars form: gravitational instability. We have pretty good models of that.

[bombastic bob]

Re: Unhelpful sugestion

I think most of the assumptions are that the first stable condensations of matter were as hydrogen, and then it started collecting together from gravity, then fusing into He and Li as unstable proto-stars, and repeatedly blew up in a series of supernovas etc. until we got some stable stars out of it that formed galaxies, etc.. Or something like that.

But hey, your guess is as good as mine, if we can't travel in time to observe it [or make it happen in a lab]. Well, as long as it fits the known science, anyway.

staring back into time with a telescope, though, almost as good as time travel if you can collect enough photons from that far away...

[Anonymous Coward]

Re: Unhelpful sugestion

Obviously that would be a possible conclusion. But we have pretty good models of big-bang neucleosynthesis and they don't predict heavy elements coming out of the big-bang, while making other predictions – notably the amount of helium in the universe and the amount of deuterium: stars actively reduce the amount of deuterium so the main source of it must be something else, which we think is BBN – which seem to be experimentally true.

The reason BBN is not expected to produce heavy elements is really two things.

Firstly there's an awkward gap in stable elements after helium: helium has 4 nucleons (2 protons, 2 neutrons), and there are no stable nuclei with 5 or 8 nucleons, so He + He goes nowhere stable, and He + H goes nowhere stable. You get a little lithium which I think happens from tritium (3 nucleons) & helium (4), and the tritium arrives from deuterium + neutron I think.

Secondly all the other pathways don't have time to happen during the big-bang. For instance consider the triple-alpha process which is how stars make carbon from helium: this is basically 4He + 4He to make 8Be (which is unstable) followed by 8Be & 4He to make an excited 12C, which usually decays back into 3 4Hes again, but occasionally (once in 2000 times or something) spits out 2 photons and turns into 12C. This has two nasty problems: it is very slow (the rate at which carbon is made is very low) and it requires very high temperatures to produce 12C at any significant rate: more than 10^8K. But the temperature of the universe only stays high enough for less than 100 seconds, which just isn't long enough to make any significant amount of carbon. Stars can do it, late in their lives, because they can keep their core temperatures really high for millions of years, but the big bang can't: the time between the point at which it's cool enough for any nucleosynthesis at all and when so cool that nucleosynthesis stops is only a few minutes.

Well, OK, there can be two things which would make this wrong: first of all perhaps the big bang stayed hot for much longer than we think it did. That would mean that basically everything we understand about it is wrong and a lot of other predictions we've done experiments on (the CMB for instance) would need other explanations. Secondly perhaps everything we know about nucleosynthesis is wrong. But this stuff is pretty well-tested: people have spent a lot of time hurling nucleons at each other and looking at what comes out and working out the statistics and making theories which predict those statistics, and those theories work pretty well: we look at stars and can predict how they do nucleosynthesis and the predictions seem to be pretty good.

So it seems pretty unlikely that BBN made a lot of heavy elements. It would obviously be amazingly cool if it did because 'oh, everything we thought was true turns out not to be' is just what physicists want to happen as they get to write lots of cool papers and become famous rather than just more 'we tested GR again, it passed again' papers: everyone wants to live through a scientific revolution, really.

[Anonymous Coward]

Re: Unhelpful sugestion

First, if heavier elements were formed in the big bang there would be no Population III stars since all stars would contain heavier elements.

The study points to a different, and fascinating, hypothesis - that super massive black holes were formed first, drew in primordial Hydrogen, Helium, and Lithium to form a proto-galaxy, reionized the early universe via energy released from their localized accretion disks, and spurred the creation of Population III stars within their proto-galaxies.