Powerful cosmic explosions left abundant stardust in our solar system

[Admin]

Stardust provides the building blocks that form new stars and planets. New research shows a significant proportion of this stellar material may have been left in the solar system by giant stars going supernova.

Powerful cosmic explosions left abundant stardust in our solar system : Read more

 

[Mergatroid]

Articles like this just confuse me.

Perhaps the authors think their readers are more knowledgeable, but for myself, although I read and watch a lot of science articles and videos, this one doesn't make any sense.

I thought ALL matter other than hydrogen and possibly helium or some helium came from super nova explosions?

If it didn't come from that source, where did it come from?

From other science articles and videos, I gather that we are all "star stuff", and in fact we are the universe made manifest, perhaps trying to understand itself.

Where did the other 75% of the "dust" in our solar system come from if it's not from super nova? Even if it came from a planet, that planet came from super nova, so again the question is, if it's not from a super nova, where did it come from?

 

[Catastrophe]

No, you have nucleosynthesis up to iron Fe. then you have to rely on other reactions. Energy is then required, and, for higher members, that comes from sources such as supernovae.

Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang, through nuclear reactions in a process called Big Bang nucleosynthesis. Bold is original.

Nucleosynthesis - Wikipedia

Cat

 

[Unclear Engineer]

Drawing on previous articles here in Space.com, it seems that there are several types of astronomical events that can fuse matter into heavier nuclides than iron. Besides solitary giant stars having collapse events (supernovas), there are also accretion event on white dwarf stars and neutron stars, and collision/mergers of neutron stars with regular stars, as well as collision/mergers between 2 neutron stars.

So, it would have been a lot more educational if this article had provided the fractions of the dust that were previously thought to have come from each source, and the changes to those fractions made on the basis of the recent work on this subject.

 

[rod]

Reporting on the precise quantities of presolar grains and the early, dust assumed to be in the 4.57 Gyr solar nebula is more than a challenge. The model interpretation of presolar grains requires r-process elements to form and then somehow, enter the solar nebula while other dust not from presolar grains is present.

Reference paper, Dust from supernovae and their progenitors in the solar nebula, https://www.nature.com/articles/s41550-022-01737-5, 01-August-2022. "Abstract Pristine stardust grains from the interstellar gas and dust cloud from which our Solar System formed some 4.57 billion years ago are present in small quantities in primitive Solar System materials, such as certain types of meteorite, interplanetary dust particles and cometary matter. As these grains are older than our Solar System, they are known as presolar grains. They can be recognized because they carry large isotopic abundance anomalies that are the result of nucleosynthetic processes in their parent stars, namely, asymptotic giant branch stars, supergiants, supernovae and novae. From astronomical observations and dust-evolution models, it is still not clear to what extent various stellar sources, especially supernovae, contributed dust to the interstellar medium..."

So, even the ISM has contribution of dust issues too (*it is still not clear*). My observation. This model answer for the origin of presolar grains said to be dated older than the solar nebula (4.57 Gyr) found today, relies upon past generations of stars to create the presolar grains via r-process (and perhaps some s-process elements) and deliver the presolar grains into the postulated MMSN and protoplanetary disc of our early solar system. The postulated early, protoplanetary disc in our solar system cannot be observed today and the stars postulated that created the presolar grains said to be in our solar system when it was born, cannot be seen either (past generations). Other stars with discs observed vary immensely in size and mass too, example Catalog of Circumstellar Disks Defining how much dust and gas mass these contain and showing r-process grains in them, looks challenging.

 

[Unclear Engineer]

First, I must say that it seems to me that all of the materials in the dust in our solar system today seems like they must be "older than the solar nebula" because I don't think our sun is producing dust materials up to this point in its evolution. So, the wording seems odd.

I was thinking that the point of the article has more to do with what fraction of the dust material was created by giant star supernovas, and what fraction was created by other processes before our solar nebula formed.

So, when looking for particles in meteorites that have "odd" isotopic compositions, aren't they looking for thing that are abnormal in the dust that formed our solar system, which is all pre solar nebula material? I understand that the solar nebula tended to sort out various materials so that their relative abundances differ in various parts of the solar system. So, are they really saying that they are looking for grains of dust that have not been changed by the solar nebula's processes? That doesn't seem consistent with talking about what fraction of those grains have elements created by supernovas of early giant stars.

 

[rod]

I note that dating dust and presolar grains in the postulated, primordial protoplanetary disc in the solar system requires some juggling The dust we see today in the ecliptic known as zodiacal light is very short lived relative to the time span of 4.57 Gyr used in the space.com report.

Comet fragmentation as a source of the zodiacal cloud, Comet fragmentation as a source of the zodiacal cloud - NASA/ADS (harvard.edu)

"Thus much of the dust seen today was likely deposited as larger grains ~0.1 Myr in the past. The model also finds the dust level to vary stochastically; e.g. every ~50 Myr large (>100 km) comets with long dynamical lifetimes inside Jupiter cause dust spikes with order of magnitude increases in zodiacal light brightness lasting ~1 Myr."

Dating the age of the dust in the solar nebula (whether presolar grains or other dust particles), requires juggling concerning meteorite ages, composition, and various young ages found for dust in the ecliptic today that does not match the 4.57 Gyr age for the solar nebula used.

My observation. 1. The presolar grains are considered older than 4.57 Gyr (how much older I did not see disclosed). 2. The solar nebula dust is dated 4.57 Gyr. 3. The dust seen in the zodiacal light today is dated perhaps 0.1 Myr and increase dust variations that brighten the zodiacal light may last perhaps 1 Myr.

This is quite an age spread, older than 4.57 Gyr, 4.57 Gyr solar nebula, and dust 0.1 Myr or so observable today in the ecliptic.

 

[Unclear Engineer]

My point is that dust that comes in from comets is probably not any different than the dust that was originally in the accretion disk 4.6 billion years ago, and was probably made by the same supernovas.

So, is the point of this story that maybe 25% of the dust in the ecliptic plane now has arrived there "recently" (in cosmic time scales)?

 

[rod]

My point is that dust that comes in from comets is probably not any different than the dust that was originally in the accretion disk 4.6 billion years ago, and was probably made by the same supernovas.

So, is the point of this story that maybe 25% of the dust in the ecliptic plane now has arrived there "recently" (in cosmic time scales)?

Certainly, the dust seen today in the ecliptic and zodiacal light is of a recent origin, that is why we can see it today. The reference paper I cited in #5, Dust from supernovae and their progenitors in the solar nebula, https://www.nature.com/articles/s41550-022-01737-5, 01-August-2022, discusses dust in the ISM using time scales of 1-3 Gyr and even 9 Gyr time scales to mix into the ISM (and somehow gets mixed into the early solar nebula too). The paper uses super-AGB stars in the interpretation to explain r-process and s-process elements observed in some meteorites today. "presolar dust from a single type of stellar source, but suggest contributions from intermediate-mass AGB stars, super-AGB (8–10 M⊙) stars, supergiants and supernovae30,32."

Plenty going on in the model interpretation to explain the observations and reconcile the different age scales used. Comets for example must be resupplied over Gyr periods in the solar system from the Oort Cloud (something we do not see), and we do not see the super-AGB stars either that created the presolar grains in some of the meteorites. When it comes to young dust observations in the ecliptic, this is seen today and with a short lifetime scale. Dust sources and time scale reconciliation methods and interpretations must be applied

 

[Unclear Engineer]

My problem with this article seems to be that it is talking about molecules and I am thinking about atoms. I assume the authors agree that all of the atoms heavier than helium were made in stars by various mechanisms. The point of the article seems to be differentiating between grains of dust of various chemistries, and which were produced directly during the supernovas and which were later assembled in the interstellar space by other mechanisms, such as shock waves (from supernovas). And, then there is the effects of the sun on the accretion disk and later ecliptic dust material. So, the thrust of this article seems to be that there is more dust material that is unaltered by the sun than previously supposed.

But, the article jumps around between talking about the isotopes created in the stars and the grains of dust that contain them in various chemical forms.

So, what I am finally getting out of this is that, looking at the isotopes in some unmodified dust particles, the authors of the study think that there are more made by supernovas of supergiant stars than they previously thought.

As I posted before, this article and the paper itself would be a lot clearer if it contained a list of the sources of the dust particles and gave their fractional contributions to the total, and how that has changed with this new study.

 

[rod]

When it comes to *their fractional contributions to the total*, I would want to see a timeline for the r-process and s-process element creation and presolar grain injection time scales into the solar nebula some 4.57 Gyr ago. Today the Sun completed about 20 galactic years since its birth, How long is a galactic year? | Live Science

Did presolar grains stop entering the solar system after the meteorites formed or is there ongoing formation and entry into the solar system today after some 20 galactic years? Interesting paper though used for the study.

 

[Unclear Engineer]

As the headline, "Powerful cosmic explosions left abundant stardust in our solar system" seems to put the focus on a star type, "supergiant stars", whose supernovas create "unusual isotope patterns not common in the solar system."

Starting from that, and trying to understand the intended message in the article, I am still puzzled.

It seems to imply that no supergiant stars went supernova in our cosmic neighborhood since the sun and our solar system was formed, 4.57 billion years ago. But, is that true? I guess that looking at the isotopic ratios of the "presolar" grains can provide a date for their creation (provided we actually have the initial nucleogenesis figured out correctly). So, "older than the age of the sun" seems to be reasonably supportable.

But, it is strange that these grains have isotopic ratios that are "not common in the solar system." The formation of the sun is not going to change the atomic nuclei of the elements in the dust in the vicinity. So, to get a different isotopic ratio, wouldn't that require that the rest of the elements were created by something other than supernovas of gigantic stars? What were the other processes that created different isotopic ratios? Supernovas of smaller stars? Collisions of neutron stars? Where did the rest come from?

And, if there is something like 25% contribution of those grains from ancient "supernovas of supergiant stars" in our "primitive" accretion disk materials like comets and (maybe) meteorites from asteroids, wouldn't that imply that the intergalactic dust that is in the local vicinity, but did not get sucked into our sun's accretion disk, should still have that ratio of dust grains with the unusual ratios of nuclides? Or, have other nucleosythesis events been going on "nearby" in the last 4.57 billion years to change that ratio since the solar system formed?

If I have understood all of this correctly, then I would think that the average mixture of radionuclides that is in our solar system today should not be any different than the average of the radionuclides in the interstellar dust in the vicinity of our solar system, unless that has changed since the solar system formed. So, the point of this article would seem to be that supergiant star supernovas created about 25% of the "metallic" elements (those that are not hydrogen or helium) in our solar system and the rest were created some other way.

There seems to be some misleading quibbling about the term "star dust" between the scientific and popular media, with the popular media saying "We are all made of 'star dust'" and some scientists quibbling about the term "dust" as opposed to "elements formed in stars" and seeming to say that those elements that were created in stars but did not condense immediately into dust grains and stay unchanged for billions of years is now "dust" but not "star dust".

So, there are just 2 slightly different definitions being conflated and then argued.

 

[Helio]

Interesting article, but it is a bit ambiguous in certain areas.

Here is a link to the article. [Space.com is diligent in giving us the reference article that will always say more, often too much for my brain.]

If I understand from my cursory read of the Nature Astronomy article, the 4.57 billion age is how old from now, not as stated here, "This process was occurring in our region of space over 4.6 billion years before the formation of the sun and its planets."

Thus, the SN (though the NA article suggests that it could be more than one) would have been just prior to the cloud collapse -- not 4.57 billion years prior to it -- and likely (IMO) a major reason for the collapse. SN and supersonic flows within clouds are the main triggers for collapse, IIRC.

Jeff Hester was the first, I think, that discovered evidence of SN activity prior to our system's beginning, though I doubt he had any clue as to how much SN's contributed to the Sun's placental cloud. [Hester's textbook was the earliest one I found that explicitly stated that the Sun is a white star, so, of course IMO, he's a genius!]

Also, note that this isn't just about SN, but also about the progenitor stars' contribution prior to it becoming a SN. This is not mentioned initially in the Space.com article, but it was thereafter.

Nucleosynthesis involves a number of sources. There are about 7 different sources needed to complete the periodic table. Here is a nice version of that table that shows where each element came from.

The > 25% amount (>30% for silicates) is the portion that are isotopes from the sources 4.57 billion years ago, so, I assume, the balance is from older sources. For instance, silicon, apparently, is only formed from SN and WD explosions. So do Si isotopes decay over very long periods, losing their isotope status, or is most Si formed without an unbalance in neutrons? The >30% discovery seems to provide age of formation to this story, perhaps. I'm unclear how these pieces come together in this puzzle. [Reading the NA article might help me, I suppose. ]

 

[Helio]

There seems to be some misleading quibbling about the term "star dust" between the scientific and popular media, with the popular media saying "We are all made of 'star dust'" and some scientists quibbling about the term "dust" as opposed to "elements formed in stars" and seeming to say that those elements that were created in stars but did not condense immediately into dust grains and stay unchanged for billions of years is now "dust" but not "star dust".

"Star dust" is likely deemed redundant in astronomy since only H & He (traces of Li, etc.) were formed without stars. Astronomers seem to prefer the term "metals", which is anything other than H & He.

 

[Unclear Engineer]

Thanks for that link, Helio. I did read the NA article, and some others, trying to get an idea of what the periodic table element origins were, but did not find the link you just provided. The NA article is quite intricate with the analyses for various elements and molecules in grains of various sources, but does not present the big picture in the link that you dug out for us.

 

[Unclear Engineer]

"Star dust" is likely deemed redundant in astronomy since only H & He (traces of Li, etc.) were formed without stars. Astronomers seem to prefer the term "metals", which is anything other than H & He.

Well, calling the inert gases other than helium "metals" seems like a definition problem, too.

People who write stories for popular media need to be mindful that some jargon specific to specialized science niches is misleading to readers outside that niche.

And, some writers get into quibbles, such as arguing that "We aren't really made of 'star dust' like some romantics have said." The general public is not going to draw a distinction between dust made of elements created in stars that became dust "immediately" and dust made of the same elements from the same sources that became dust "later". And, it isn't as if the issue is not recognized - people are getting paid for writing articles that make quibbles about the definitions.

 

[Helio]

Well, I can appreciate why authors don't want tell us we are mostly metals. The aesthetic use of "star dust" isn't unreasonable, IMO, even if it includes some hyperbole. Perhaps Sagan was the first, or the first to popularize it, but this was for public consumption and to get folks to think about our elementary beginnings, furthering support, perhaps, for other science ideas like evolution.

 

[Catastrophe]

Helio,

and likely (IMO) a major reason for the collapse

I certainly do not disagree with this; after all, you do say 'major', but, without meaning to apply 21st century human thinking to the BB, I cannot see, by whatever mechanism, perfect uniformity of 'particles' which would need SN activity to start clumping.

Cat

 

[Catastrophe]

Whilst on the subject of BB, I am not going to miss any opportunity to promote the essential fact that "BB" should not be used to describe both the workings of science and the unknowns around (very close to) t = 0, 'in the same breath'.

Cat

 

[Unclear Engineer]

Helio, I don't even agree that it is "hyperbole" to say that everything (except hydrogen and helium) is made from "star dust" if we understand that "star dust" is the product of stars. It is not an exaggeration or stretching of the truth.

Now, calling neon, xenon, radon and argon "metals" seems unwarranted. Why not make up a new term for everything except hydrogen and helium? Maybe "STONs" for stellar origin nuclides (and please leave off the final "e" from "nuclides", because "stones" is already taken.)

 

[Helio]

Helio,I certainly do not disagree with this; after all, you do say 'major', but, without meaning to apply 21st century human thinking to the BB, I cannot see, by whatever mechanism, perfect uniformity of 'particles' which would need SN activity to start clumping.

As I understand it, giant gas clouds are usually quite comfortable being what they are. If they should compress a little, they will heat-up, then expand back. This allows them to remain clouds for as long as they have, though new clouds will form, no doubt, when things like galaxies pass near or through one another.

So something has to trigger them in order to create fragmentation, whereby many of these fragments will reach a density state that will allow a full collapse to form a star.

Supernovae explosions will blast into a cloud compressing it, which can trigger collapse. See Jeans Instability.

But clouds are not purely homogenous. Events, internal and external, will produce flows within the cloud. Given their low density, these flows can become supersonic, which produces shockwaves that can, in theory, trigger fragmentation and collapse.

 

[Helio]

Whilst on the subject of BB, I am not going to miss any opportunity to promote the essential fact that "BB" should not be used to describe both the workings of science and the unknowns around (very close to) t = 0, 'in the same breath'.

Yes. One big breath, and one meta-breath.

 

[Catastrophe]

Helio,

and likely (IMO) a major reason for the collapse

As I remember it, and it was a very long time ago, I am sure that it was not 100% perfectly regularly spaced out particles with no local concentrations whatsoever.

But I do acknowledge that some form of vibration could well trigger accretion.

Cat

 

[Rusty]

In hopes of not "rocking" the boat, I am extremely curious to know where the information that was contained in the "original" singularity came from?...

From my very minuscule understanding of astronomy to my chagrin, I haven't been able to find a reasonable "scientific" explanation for this question!...

In advance, please forgive my undesired ignorance...I am trying to learn!!!.....

 

[Catastrophe]

Rusty,

I am extremely curious to know where the information that was contained in the "original" singularity came from?...

Welcome. We are all here to learn.

Initial singularity - Wikipedia
https://en.wikipedia.org › wiki › Initial_singularity

The initial singularity is a singularity predicted by some models of the Big Bang theory to have existed before the Big Bang and thought to have contained ...

Yes, I think it came from the backwards extrapolation of "expanding", which, to my mind, is being taken far too far. Personally, I prefer a BH->nexus->BB->nexus-> . . . . . . cycle to a singularity.

I think Lemaître may have had a hand in it, he proposed the "Big Bang theory" involving a primeval atom, which has some commonality with a singularity.

Georges Lemaître - Wikipedia

https://www.amnh.org/learn-teach/curriculum-collections/cosmic-horizons-book/georges-lemaitre-big-bang

Cat