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I need an astrophysicist stat!


ArmchairGravy

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I've had a question bugging me for several months now relating to how we have dated the formation of the solar system, and can't find an answer. Hopefully someone here can help.

From what I understand, we have used the proportion of lead/uranium in meteors to determine the solar system formed roughly 4.5 billion years ago. However, the uranium we are measuring was formed in a supernova explosion. Are we therefore not measuring the age of the solar system but instead measuring how long ago the supernova explosion that created the materials the solar system is made from?

It seems there would be a gap in time between the creation of the uranium and the coalescence of our solar system. Is this time gap accounted for and if so, how?

Thanks in advance for your help!

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When rocks form, the chemical and physical processes result in elements separating. Zircon crystals, for example, can incorporate Uranium atoms into their structure in place of the occasional Zirconium atom, but this does NOT happen with Lead atoms. So the Lead you find in that zircon crystal later came from Uranium decaying.

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I did read where the clocks get reset during rock formation, and thought this was the reason we were using meteors to find the date. I didn't realize the same temperatures and pressures were involved during the formation of the solar system. Would it be possible to find some "primordial uranium" in the outer reaches of the solar system that would not have been reset? The linkage between "the solar system is 4.5 billion years old" and "everything heavier than iron comes from supernova" really isn't well explored in popular science media.

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We might not have good enough models to predict isotope composition of supernova fragments. The heavy elements are generated as the shock passes through outer layers of neutron matter in a freshly collapsed core. This is RQFT on steroids. Not only are we limited on models here, but we do not have computing power to use the ones we have.

There might be some general stat mech arguments for rough initial distributions. And it might be worth running some Monte Carlo on these to see what distributions they yield over time. It is conceivable that precise details of initial distribution are irrelevant.

This could be fun to try, as it would, indeed, give us an age of this star system in terms of time elapsed since nova. Provided, of course, that there was just the one contributor. I have always wondered if it would ever be possible to track our system's progress far enough back to find the origin of the nova and, maybe, Sol's sister stars.

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The reason we use meteorites is because Earth is very geologically active, so most of its surface rocks were formed relatively recently, and older rocks get destroyed. But the small sizes of the asteroids mean that they cooled off soon after formation and ceased being geologically active...so when they get bashed apart and the pieces fall on Earth as meteorites, we have rocks that are much more likely to come from a time close to the formation of the solar system.

This isn't the only method we use to determine the age of the solar system. We can also use helioseismology data to tell from the interior structure of the Sun how much of its hydrogen it has turned into helium in its core, and that also gives use an age of around 4.5 billion years (but it's not as precise as radiometric dating).

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I thought we already found some cluster in Virgo that we are going away from directly... ?

Regarding OP's question: you don't need to worry about which SN created us. As matter acretes, they'll differentiate - and this differentiation is what "refresh" the dating. Same goes for radiocarbon - C-14 only inhaled when you're alive. Probably what will be revealing when the SN was is to look for sun's metalicity (with a fair amount of correction I guess).

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I thought we already found some cluster in Virgo that we are going away from directly... ?

If you mean Messier 67, I think that's been ruled out.

http://news.nationalgeographic.com/news/2012/01/120117-sun-solar-system-born-stars-m67-space-science/

@OP As I recall, a group of scientist looking for the origin of the water in our solar system think that a large part of it formed before our Sun did. They did that by looking at concentrations of deuterium in water.

So I assume there are many different ways for astronomers to estimate the solar systems age.

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I did read where the clocks get reset during rock formation, and thought this was the reason we were using meteors to find the date. I didn't realize the same temperatures and pressures were involved during the formation of the solar system. Would it be possible to find some "primordial uranium" in the outer reaches of the solar system that would not have been reset? The linkage between "the solar system is 4.5 billion years old" and "everything heavier than iron comes from supernova" really isn't well explored in popular science media.

It is possible some dust grains are lurking around in the solar system that were never part of a larger body, the difficulty is collecting them. The only way we could conceivably collect them is from a mission like Stardust, however Stardust went through a cometary tail so any dust particles collected are likely contaminated with other elements.

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Hmm... Either faulty source or I read wrongly... M67 in Cancer anyway. Also I'm not aware of any other bright DSO in Virgo bar lots of galaxies...

I think that Sun is a "runaway star" (not HSV though) - that is, sun is among stars that are expelled as soon as it formed (some simulation shows that this is quite numerous). Or probably our cloud was special... are there any discoveries of clusters of only low-mass star or so ?

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Open clusters don't tend to stay together forever. M67 is already considered old, and it's younger than Sol. NGC 188 is apparently one of the oldest known, and it is 5b years old. The only reason it's still together is that it's located above the disk.

It seems likely, from everything I've gathered, that whichever cluster Sol came from, no longer exists as a cluster. Its stars scattered across considerable distance. Sol would have been one of the smaller stars of the cluster, and these tend to end up on the outside. This might be the reason we are having trouble finding Sol's sisters.

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It seems likely, from everything I've gathered, that whichever cluster Sol came from, no longer exists as a cluster. Its stars scattered across considerable distance. Sol would have been one of the smaller stars of the cluster, and these tend to end up on the outside. This might be the reason we are having trouble finding Sol's sisters.

After about twenty-two orbits around the galaxy, it's reasonable to suppose we will never find any of Sol's sisters- not with any kind of certainty, at least. We might find some stars that are similar enough in age and composition and orbit to maybe be related. The stars born with the Sun would be spread out in a huge arc stretching possibly all the way around the galaxy by now.

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