# 'We are stardust': A few questions, please. **URL:** \ **Category:** Factual Questions\ **Created:** [April 28, 2015, 6:04pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732 "2015-04-28T18:04:01Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [April 28, 2015, 6:04pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/1 "2015-04-28T18:04:01Z")
Despite its meme status, I still think it’s pretty awesome that ‘we are stardust’. I have some questions in this regard and wonder if someone can, please, enlighten me. 1. Would one star going supernova supply enough of the necessary ‘heavy elements’ to form our Solar System (and its denizens, i.e. _us_). Or, has the Solar System formed from the commingled mess of a multitude exploded stars? Simply put, are we stardust or stars’ dust? 2. What type of star(s) would have been the likely suppliers of the stuff that now makes up our Solar System? Are such stars special in any way, or are they common throughout the Universe? 3a. Does it make any sense to consider _which particular_ star’s (or stars’) detritus supplied the raw materials for our Solar System? 3b. Is there any way, even in theory, to identify the specific supernova remnant(s) (or other potential evidence) from which our Solar System formed eons later? Thanks! ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 28, 2015, 8:07pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/2 "2015-04-28T20:07:49Z")
1. Stars’ dust. It took many supernovae to enrich the interstellar medium to Solar metallicity levels. 2. The most massive stars. The more massive, the faster they burn through their fuel and go supernova. 3a. No 3b. No. We can see a number of SN remnants, but they’ve all been produced in the relatively recent past. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 28, 2015, 9:33pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/3 "2015-04-28T21:33:33Z")
I just realized that my answer for 3b might be misleading. to those unfamiliar with the terminology. A supernova remnant is the nebula produced by a supernova. The material given off by the supernova forms a shockwave as it impacts the interstellar medium(ISM). This is only visible for perhaps a few tens of thousands of years after the supernova. The Crab Nebula is perhaps the most famous supernova remnant. The term does not refer to the neutron star or black hole that the supernova produces. Those stay around indefinitely, of course. All of them contributed to enriching the ISM, but it’s impossible to say how much any particular one contributed to the Solar System. Now there may have been one particular supernova that caused the collapse of a gas and dust cloud to form the Solar System. It contributed certain relatively short-lived radioactive elements. In theory, it might be possible to identify this particular neutron star/black hole, but it’s unlikely that will happen. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 28, 2015, 10:03pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/4 "2015-04-28T22:03:21Z")
Especially since it’s really hard to find isolated neutron stars, and even harder to find isolated black holes. We mostly find both of them from either their effects on the orbits of other stars, or from them accreting material from other stars. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 28, 2015, 11:33pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/5 "2015-04-28T23:33:34Z")
> [@dtilque](#): > > 1. Stars’ dust. It took many supernovae to enrich the interstellar medium to Solar metallicity levels. > > 2. The most massive stars. The more massive, the faster they burn through their fuel and go supernova. > > 3a. No > > 3b. No. We can see a number of SN remnants, but they’ve all been produced in the relatively recent past. How long has our solar system been isolated from other interstellar clouds or star systems? We are several light years from the nearest stars, has our solar system been made of interstellar star stuff or has it been one star being born and dying in isolation that gave birth to our current solar system? ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [April 29, 2015, 12:04am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/6 "2015-04-29T00:04:06Z")
> [@dtilque](#): > > The term does not refer to the neutron star or black hole that the supernova produces. Those stay around indefinitely, of course. All of them contributed to enriching the ISM, but it’s impossible to say how much any particular one contributed to the Solar System. Some supernovas leave no remnant at all-the explosion blows the entire star apart. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [April 29, 2015, 12:42am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/7 "2015-04-29T00:42:17Z")
Thanks for all the replies. I hadn’t realized that the ‘halo’ (or however it’s best labeled) formed by a supernova is so short-lived - only thousands of years. Any idea as to how many ‘typical’ supernovae it must have taken to form enough of heavy elements to form the Solar System? Are we talking single digit numbers? Thousands? What is the likely order of magnitude? Thanks! ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 29, 2015, 12:48am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/8 "2015-04-29T00:48:02Z")
> [@John\_DiFool](#): > > Some supernovas leave no remnant at all-the explosion blows the entire star apart. You misunderstood. I was trying to make the point the “supernova remnant” has a specific meaning in astronomy. That meaning is the nebula formed by the rapidly expanding gasses hitting the ISM. It does not refer to the neutron star/black hole. In the cases you’re refering to (type Ia), there is no neutron star or black hole left, but there still will be a remnant. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [April 29, 2015, 12:49am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/9 "2015-04-29T00:49:42Z")
We are billion year old carbon. ---
**Author:** ![flano1](https://avatars.discourse-cdn.com/v4/letter/f/f14d63/32.png) [@flano1](https://boards.straightdope.com/u/flano1)\ **Post date:** [April 29, 2015, 3:38am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/10 "2015-04-29T03:38:07Z")
beat me to it. ---
**Author:** ![Kenm](https://avatars.discourse-cdn.com/v4/letter/k/bc79bd/32.png) [@Kenm](https://boards.straightdope.com/u/Kenm)\ **Post date:** [April 29, 2015, 4:49am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/11 "2015-04-29T04:49:26Z")
I thought I remembered Carl Sagan saying that at least three generations of supernovae were required to produce the heavier elements making up us. So I ran a search and found [**this**](http://www.universetoday.com/117607/how-many-stars-did-it-take-to-make-us/) that includes a video. > [@](#): > > . . . So how many? How many times has this cycle been repeated? We don’t know. Lots. There were the original stars that formed shortly after the Big Bang, and then successive generations of massive stars that formed in various nebulae. Astronomers are pretty sure it was a least 3 generations of supernovae, but there’s no way to know exactly. > > Carl Sagan said you’re made of star-stuff. But actually you’re made up mostly of Big Bang stuff and generations of supernova stuff. Tasty tasty supernova stuff. The first in the list of search results [**was this**](http://www.pbs.org/wgbh/nova/space/star-in-you.html), written by Peter Tyson, editor in chief of NOVA Online. > [@](#): > > . . . You and everything around you, every single natural and man-made thing you can see, every rock, tree, butterfly, and building, comprises atoms that originally arose during the Big Bang or, for all but the lightest two or three elements, from millions of burning and exploding stars far back in the history of the universe. You live because stars died; it’s that simple. . . . ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 29, 2015, 6:59am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/12 "2015-04-29T06:59:08Z")
> [@Leaffan](#): > > We are billion year old carbon. More like 5 to 12 billion year old carbon, if you want to be pedantic rather than poetic. > [@KarlGauss](#): > > I hadn’t realized that the ‘halo’ (or however it’s best labeled) formed by a supernova is so short-lived - only thousands of years. As I indicated above, [**remnant**](http://en.wikipedia.org/wiki/Supernova_remnant) is the technical term. > [@](#): > > Any idea as to how many ‘typical’ supernovae it must have taken to form enough of heavy elements to form the Solar System? Are we talking single digit numbers? Thousands? What is the likely order of magnitude? Consider that the Milky Way is about 10 billion years old and currently there’s a supernova every 50 years somewhere within it. Making a linear extrapolation, that gives 200,000,000 supernovae over the history of the galaxy. The Sun is some 4.6 billion years old, so about half of those happened after the Sun formed. So a very rough order of magnitude is 100 million. That’s over the entire Galaxy, of course, the number that directly contributed to the Sun would be much less. The generations that **Kenm** brought up apply to the amount of metallicity in the stars. The initial generation was made of Big Bang produced elements, meaning no metals (elements heavier than helium are called metals by astrophysicists). Later generations would have progressively more metals. But these generations are kind of nebulous (excuse the pun). The stars that go supernova live for very short times as stars go: between half a million to maybe 10 million years. So if there’s only a few generations, there would be time for many supernovae per generation. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 29, 2015, 1:02pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/13 "2015-04-29T13:02:05Z")
> [@KarlGauss](#): > > … I hadn’t realized that the ‘halo’ (or however it’s best labeled) formed by a supernova is so short-lived - only thousands of years. … AIUI, the halo lasts a lot longer than that, slowly expanding and dissipating all the while. It just doesn’t glow brightly enough to be detected by Earthling astronomers for more than a few thousand years. So we can’t find the older ones. ---
**Author:** ![dasmoocher](https://avatars.discourse-cdn.com/v4/letter/d/dbc845/32.png) [@dasmoocher](https://boards.straightdope.com/u/dasmoocher)\ **Post date:** [April 29, 2015, 2:00pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/14 "2015-04-29T14:00:34Z")
> [@](#): > > . . . You and everything around you, every single natural and man-made thing you can see, every rock, tree, butterfly, and building, comprises atoms that originally arose during the Big Bang or, for all but the lightest two or three elements, from millions of burning and exploding stars far back in the history of the universe. You live because stars died; it’s that simple. . . . As an aside, I once blew my friend’s mind when I told him this back in high school. His question was “Where does it all come from?” The doobie he was smoking probably helped. 🙂 ---
**Author:** ![rsa](https://avatars.discourse-cdn.com/v4/letter/r/839c29/32.png) [@rsa](https://boards.straightdope.com/u/rsa)\ **Post date:** [April 29, 2015, 9:27pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/15 "2015-04-29T21:27:01Z")
The process of producing heavier elements is called nucleosynthesis. Wikipedia has a good [nucleosynthesis article.](http://en.wikipedia.org/wiki/Nucleosynthesis) ---
**Author:** ![Lukeinva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lukeinva/32/17872_2.png) [@Lukeinva](https://boards.straightdope.com/u/Lukeinva)\ **Post date:** [April 30, 2015, 1:20am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/16 "2015-04-30T01:20:51Z")
Don’t forget that, also, we are golden. ---
**Author:** ![dba\_Fred](https://avatars.discourse-cdn.com/v4/letter/d/c37758/32.png) [@dba\_Fred](https://boards.straightdope.com/u/dba_Fred)\ **Post date:** [April 30, 2015, 11:05am UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/17 "2015-04-30T11:05:35Z")
If you believe the Doors, [Out here on the perimeter there are no stars Out here we is stoned - immaculate.](http://www.azlyrics.com/lyrics/doors/thewasptexasradioandthebigbeat.html) ---
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [April 30, 2015, 3:21pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/18 "2015-04-30T15:21:52Z")
My question: when a 1st -generation star explodes, the metals, heavy elements are flung out at enormous speeds. How does the residue “agglomerate” into a new start (and planets). It would seem that such a process would take a long time. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [April 30, 2015, 3:34pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/19 "2015-04-30T15:34:12Z")
> [@ralph124c](#): > > My question: when a 1st -generation star explodes, the metals, heavy elements are flung out at enormous speeds. How does the residue “agglomerate” into a new start (and planets). It would seem that such a process would take a long time. Remember matter likes to clump together. The nebula formed by the explosion does not completely disburse. It travels through space till it runs into some more cosmic dust. Eventually there is enough in one area that stars can start forming out of the gas such as we see in the [Pillars of Creation](http://www.nasa.gov/content/goddard/hubble-goes-high-definition-to-revisit-iconic-pillars-of-creation). And yeah, it takes a really long time for all this to occur although it probably occurred faster in the past with the first stars after the Big Bang. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [April 30, 2015, 4:52pm UTC](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732/20 "2015-04-30T16:52:46Z")
This is a good question. At the heart of the matter is what is the heaviest element naturally found in the human body? Iron may first come to mind, but what about Iodine? Iodine is heavier than iron, and a star’s core cannot continue fusion beyond iron; hence, the death of a star. So, where do the heavier elements come from? (For those unfamiliar, salt is often iodinized to get iodine into people’s diets needed to prevent the onset of problems due to a lack of iodine in the human body.) Also, consider the horseshoe crab who uses copper where we use iron in our blood. Zinc is yet another element used by the body and heavier than iron. FYI: On the Perdiodic Table of Elements: Fe = 25 Cu = 29 Zn = 30 I = 53 [Next page](https://boards.straightdope.com/t/we-are-stardust-a-few-questions-please/718732.md?page=2)