Birth of a Solar System Witnessed In Spectacular Scientific First (sciencealert.com) 31
alternative_right shares a report from ScienceAlert: Around a Sun-like star just 1,300 light-years away, a family of planets has been seen in its earliest moments of conception. Astronomers analyzed the infrared flow of dust and detritus left over from the formation of a baby star called HOPS-315, finding tiny concentrations of hot minerals that will eventually form planetesimals -- the 'seeds' around which new planets will grow. It's a system that can tell us about the very first steps of planet formation, and may even contain clues about how our own Solar System formed. The findings have been published in the journal Nature.
Is this a place where a SuperNova once happened? (Score:1)
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As for individual solar systems, accordin
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There's no "other" direction, all 'directions' are just looking back in time because light takes time to arrive from far away places. So you are seeing what happened much earlier. No way to invert that and start seeing what will happen in the future. Neither is looking 'back' like this looking back in time - its just a recorded event that already happened long ago but you are seeing it now. Like an old VHS tape of yours maybe
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We can't see the Big Bang.
We can see the "surface of last scattering", where the radiation component of the universe last interacted with the charged particles of the cooling universe - because they dropped through the temperatures where the free protons and free electrons recombine to make neutral hydrogen, which interacts negligibly with photons with a blackbody temperature less than about 3000K.This event took place about 300,000 years after the Big Bang, and fomr out point of view, at a redshift of abou
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"As for individual solar systems, according to what I just looked up, stars fizzle out and become either a white dwarf, or (for massive stars) a neutron star or black hole - but not again a star in any case."... I think that is interesting but is not intuitive to me. It is like a bunch of dust floating around, mostly hydrogen, just collapses in on itself and becomes a solar system. It seems strange. As for the "Big Crunch" theory, I have lots of thoughts about that, but I think it is still in the running as far as theories go. Apparently space can expand quickly, like at the birth of the universe, maybe it can contract quickly, and we can still have a "big crunch"?? I am also doing mind experiments as to if we look in the opposite direction to the big bang, what should we see? When we look at the big bang, we are seeing back in time, and seeing things that happened 13 Billion or more years ago. What happens when we look in the other direction?
I keep recommending this book, because it's a very humorous look at all the possible ways the universe may end, but you should check out Katie Mac's The End of Everything, Astrophysically Speaking [astrokatie.com]. While the Big Crunch is still a theory, it's not a highly favored one in her view. Far more likely to current thinking, heat death will take us, where everything in the universe becomes so spread out that there's not enough matter in any one place to keep generating energy, in extremely simple terms. But there's
The Big Rip (Score:3)
What happens when we look in the other direction?
All directions look back to the Big Bang because it happened at every point of the universe. The "Big Crunch" is pretty much ruled out by the accelerating expansion but this has introduced a new possible ending to the universe: the "Big Rip". In this scenario nothing stops the accelerating expansion driven by increasing dark energy.
As the expansion accelerates, the causally connected region of the universe shrinks and, if nothing stops this, at some point in the extremely distant future even atoms and t
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"As for individual solar systems, according to what I just looked up, stars fizzle out and become either a white dwarf, or (for massive stars) a neutron star or black hole - but not again a star in any case."... I think that is interesting but is not intuitive to me. It is like a bunch of dust floating around, mostly hydrogen, just collapses in on itself and becomes a solar system. It seems strange.
What really happens is that there are huge clouds of gas and dust that become stellar nurseries (we see one about 800 light years away in the constellation Orion). These huge clouds collapse and start producing density centers that collapse into stars, some of these a very massive, live for a short time, explode with core collapse supernovas and send shock waves and newly formed elements into the huge cloud forcing more collapses into star to form. This process continues for hundreds of millions of years un
Re:Is this a place where a SuperNova once happened (Score:4, Informative)
As for individual solar systems, according to what I just looked up, stars fizzle out and become either a white dwarf, or (for massive stars) a neutron star or black hole - but not again a star in any case.
Well, that's not quite the case. As stars age, a portion of their stellar material gets dispersed in planetary nebulae. If a star becomes a supernova, he huge explosion also disperses a lot of stellar material. Even if a star collapses to a black hole, some stellar material still gets ejected via relativistic jets.
This material, which has already been part of a star, can coalesce again, creating new stars. Supernova explosions create shock waves in the interstellar gas, creating zones of high concentration, who become new star nurseries.
The first stars after the big bang were composed mainly of hydrogen and are called population III [wikipedia.org] stars. During their lifetime, they created heavier elements (in astronomy-speak, "metals"). When population III stars died, they enriched the interstellar medium with those heavier elements, and the second generation of stars (population II stars) started their lives with higher metallicity. When population II stars died, the process repeated, and another generation (population I) came to live, reusing the stellar material of predecessor generations.
The Sun, for example, is a relatively recent population I star, and has comparably high metallicity.
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I am trying to get a sense of how many Billions of years it may take such that a rocky planet can be filled with Oxygen and Carbon, and all of the elements on the table can be produced
Well, I'm not an astronomer, so my opinions aren't in any ways authoritative; however, from what I learned, the lifetime of stars is - interestingly enough - inversely proportional to their size. Very large stars burn through their material in a mere few million [wikipedia.org] years before exploding; the smallest red dwarf are misers and can live for trillions of years.
Given the current estimated age of the universe, there was plenty of time for generations of massive stars to be born, burn brightly for a few million or h
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The carbon content of the Earth is pretty negligible. By volume it is about 50% oxygen, 10% iron, and I'd have to go looking to get a number for silicon and magnesium, but they're fairly comparable to the iron. The rest of the periodic table fits into the remaining 20% or less of volume.
Carbon is not very common on Earth because while the planetesimals which formed it were accreting and turning little mud-balls into bigger mud balls, it was too hot (locall
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As for individual solar systems, according to what I just looked up, stars fizzle out and become either a white dwarf, or (for massive stars) a neutron star or black hole - but not again a star in any case.
Well, that's not quite the case. As stars age, a portion of their stellar material gets dispersed in planetary nebulae. If a star becomes a supernova, he huge explosion also disperses a lot of stellar material. Even if a star collapses to a black hole, some stellar material still gets ejected via relativistic jets.
Additionally some white dwarfs collect enough matter to become unstable and explode throwing their entire mass back out as a mass of new elements, and some neutron star pairs merge and generate kilonovae that pump out the very heaviest elements formed in the universe due the intensely concentrated neutron fluxes produced (the r-process of element formation).
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Quibble, non-trivial :
Approximately 75% hydrogen, 25% (by nucleus count) helium. Tiny (parts per million ; 1ppm = 0.0001%) proportion of primordial lithium, if it survived the early period of rising temperature and pressure in the forming Pop1 star.
But then, yes, the amount of contamination with "metals" (anything heavier than helium) increased. Whether it increased linearly, and how well
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Not really. It had been falling out of favour for years (decades, even) before then.
The question of the long-term future of the universe essentially comes down to the question of what the average density of mass-energy in the universe is. Too high, and the universe Bangs, expands for a bit, then starts to contract and Crunches (Big Bang, Big Crunch) ; too low, and the universe Bangs, then expands in
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We have known this for decades because we can directly observe the products of planetary system formation from a supenova -- they fall to Earth all the time. They are the most abundant type of meteorite -- the chrondrite or stony meteorite.
The term "chondrite" means that is is composed of little spherical grains, or chondrules, which condensed out of the supernova debris. This is the stuff they are seeing in the HOPS-315 system. And we can tell this is "formation in place" because we can tell that the very
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Generally you're correct, but,
No. The melting of the CAIs (which in the early 2000s averaged to the memorable date of 4567 million years ; more have been measured since, but the average is still pretty close to that. And it is a memorable number. Which is why I remember it.) is thought to have been caused by the "turning on" of the early Sun. Maybe by flares as the proto-Sun was having magnetic conniptions as it approached "turn on". But
Re: Is this a place where a SuperNova once happene (Score:2)
Your draft response is insightful and philosophically sharp, but if you're aiming for maximum clarity and impact on Slashdot, where technical and skeptical readers dominate, a slight tightening of tone and structure could help. Here's a refined version that keeps your poetic edge but delivers the point more cleanly in plain ASCII:
"What if your 'feeling' is just a mood â" a passing mental weather pattern â" that seems profound only because it resonates with your current state of mind? Another perso
"Just" (Score:2)
Around a Sun-like star just 1,300 light-years away
If tomorrow someone launched a starship that could go 156 times faster than the fastest spacecraft ever launched, your (366 * great) grandchild could see this, and that's only because the time dilation reduces that by 2 generations.
Around the corner, really.
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Seems like time kind of stops for the traveler. At 0.99c they would experience a year, while the rest of the universe would advance 1,300 years. So it seems... it would not be the great great grandchildren, it could be you.
Time is quite relative to the organic human rotting away at a rate of 0.99c.
Gonna take a lot more than prayers and vitamins for you Vulcamaniacs to make it to whenever you feel 1,300 light years is away from here.
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And they would be as far from you, as you are from the first humans who got most of their calories from farmed rather then hunt/gather foodstuffs.
Arthur “Green Thumb” Dent. (Score:2)
New space exploration is cool and all (don’t forget your towel), but is there a reason we asked the professional gardener to write an article on planet formation and personify the shit out of it?
Planting planet seeds and watching our newfound baby stars take its first steps? Seriously?
Did they see God with his pick axe? (Score:2)
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So what's the use to know this? (Score:2)
Was a new technology invented to observe this?
Can we learn anything about our own solar system from this? If yes, what? Does this translate to any potential discoveries on our own planet?
Paper link (Score:2)
The link to Nature [doi.org] is behind a paywall.
Annoyingly, the paper isn't on Ariv - yet.
Researchgate just feeds you back to Nature.
I'll try to remember to look for it again next week.