<p>Some stars do form from supernova remnants. But the relative amount of heavey elements is still very small compared to hydrogen and helium. Many 2nd generation stars have more elements than the 1st generation stars.  But the percentage of these elements is still very small compared to the hydrogen in the star.</p>

CC BY-SA 4.0
2021-02-07T02:40:11.893Z
2021-02-07T02:40:11.893Z
Natsfan
<p>Supernovae are extremely energetic events. The remnants left behind by a supernova are ejected at much greater than escape velocity. Instead of coalescing due to self-gravitation, the remnants disperse and eventually spread throughout vast regions of the galaxy.</p>

CC BY-SA 4.0
2021-02-06T18:34:01.350Z
2021-02-06T18:34:01.350Z
David Hammen
<p>May be a beginner's question but I couldn't find the answer anywhere.</p>
<p>Given a supernova event and the cloud left by it, why does a new star coalesce with a disproportionally higher hydrogen(and helium) content compared to the matter left on it's vicinity?</p>
<p>Shouldn't gravity form bodies(maybe stars still) with all, or most of, the heavier elements and leave the hydrogen and helium in the vicinity instead?</p>
<p>I would also appreciate any book indications on that matter.</p>

CC BY-SA 4.0
2021-02-06T17:50:29.280Z
See https://astronomy.stackexchange.com/questions/16311/how-can-there-be-1-000-stellar-ancestors-before-our-sun/16313#16313 and https://astronomy.stackexchange.com/questions/30103/how-could-a-supernova-seed-solar-nebula?rq=1
ProfRob
<star><supernova><star-formation><planetary-formation>
After a supernova, why don't new stars coalesce with higher heavier element content?
Matheus Simon
# After a supernova, why don't new stars coalesce with higher heavier element content?

(Asked by: username_0 on 2021-02-06)

May be a beginner's question but I couldn't find the answer anywhere.

Given a supernova event and the cloud left by it, why does a new star coalesce with a disproportionally higher hydrogen(and helium) content compared to the matter left on it's vicinity?

Shouldn't gravity form bodies(maybe stars still) with all, or most of, the heavier elements and leave the hydrogen and helium in the vicinity instead?

I would also appreciate any book indications on that matter.

**Tags:** star, supernova, star-formation, planetary-formation

> **Comments:**
> **username_1**: See https://astronomy.stackexchange.com/questions/16311/how-can-there-be-1-000-stellar-ancestors-before-our-sun/16313#16313 and https://astronomy.stackexchange.com/questions/30103/how-could-a-supernova-seed-solar-nebula?rq=1  

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## 2 answers

### Answer by username_3 on 2021-02-06. Score: 5 | Accepted answer

Supernovae are extremely energetic events. The remnants left behind by a supernova are ejected at much greater than escape velocity. Instead of coalescing due to self-gravitation, the remnants disperse and eventually spread throughout vast regions of the galaxy.


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### Answer by username_2 on 2021-02-07. Score: 2

Some stars do form from supernova remnants. But the relative amount of heavey elements is still very small compared to hydrogen and helium. Many 2nd generation stars have more elements than the 1st generation stars. But the percentage of these elements is still very small compared to the hydrogen in the star.


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