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Is our solar system considered metal poor?

by vlovich123 3y ago

abainbridge 3y ago
No. I believe a metal poor solar system wouldn't have rocky planets.
- vlovich123 3y ago
  But our sun is quite young afaik (middle aged) and earth is not much younger so it’s weird to hear the reasoning that metal-poor systems implies young system…
  - metafunctor 3y ago
    Here, “young” means measured from the Big Bang. Our sun is made from the stuff of previous stars.
  - codeflo 3y ago
    I’m assuming the poster misspoke and meant that metal-poor stars have formed when the universe was relatively young, not that the stars are young. It’s also my understanding that a planet such as ours could only have formed a bit later, after enough supernovae had formed all the carbon and iron and so on that we need to live.
    - Sharlin 3y ago
      Making matters confusing is the fact that the phrase "a young galaxy" is commonly used to refer to a galaxy formed when the universe was young – if it’s far away (high redshift, z >> 1) and as such we see it the way it was when the universe was young! This specific study, however, looked for more nearby galaxies (z < 1, we see the light that was emitted a few billion years ago) so these galaxies (as we see them) are in fact "old". I think essentially all existing galaxies either formed >10 Gy ago or are the results of galaxy mergers – so in that sense there are no "young", recently-formed galaxies in the universe at all as the raw material was long ago used up. As such in astro-talk "young galaxies" can fairly unambiguously mean "far-away galaxies". But formally they’d be called high-z or high-redshift galaxies.
    - rbanffy 3y ago
      > after enough supernovae had formed all the carbon and iron and so on that we need to live. And let’s not forget some of the atoms we see around us have been through even more violent events than supernovae. Population II systems must be very boring.
pvg 3y ago
'Metallicity' in that sense is used to describe stars and the Sun, being a relatively young star is metal rich. Edit: 'young' is confusing here as pointed out in sibling comments - young compared to the age of the universe rather than young in terms of stage of stellar evolution. To make this even more confusing, this is 'population I' - younger and more metal rich unlike older, metal-poor 'population II' stars. https://en.wikipedia.org/wiki/Stellar_population#Chemical_classification_by_Baade https://en.wikipedia.org/wiki/Stellar_population#Chemical_cl...
- vlovich123 3y ago
  Ah ok. So this is about the composition of just the star and not anything about the broader system.
  - pvg 3y ago
    Yeah although like most things in exoplanetary astronomy, the relationship between metallicity and planetary systems is an area of active research with various not-totally-intuitive findings: https://www.space.com/31456-rocky-planet-found-unlikely-star.html https://www.space.com/31456-rocky-planet-found-unlikely-star... https://www.nature.com/articles/s41467-023-37195-4 https://www.nature.com/articles/s41467-023-37195-4
    - spookie 3y ago
      That Neptune sized planet sure is close to its star. Interesting
      - pvg 3y ago
        Oh they get even bigger and closer and we've seen a bunch of those because they're more readily detectable: https://en.wikipedia.org/wiki/Hot_Jupiter https://en.wikipedia.org/wiki/Hot_Jupiter
  - defrost 3y ago
    Almost pretty much the same thing really. Consider that our sun contains 99.86% of the mass of our Solar System. Bear in mind the headline is about total spectrum of elements in entire galaxies ... eg: as in looking at our galaxy, the entire milky way, from a distance that makes it dwindle to a near point and difficult to estimate how many stars make it up. Of all the many galaxies that we can see, this is a story about a handful that are mostly hydrogen and helium .. more so than what we see as typical for galaxies.
dudeinjapan 3y ago
We have Black Sabbath, Iron Maiden, KISS, Slayer, and Megadeth. I'd say we are doing alright!

Is our solar system considered metal poor?

abainbridge 3y ago

No. I believe a metal poor solar system wouldn't have rocky planets.

vlovich123 3y ago
But our sun is quite young afaik (middle aged) and earth is not much younger so it’s weird to hear the reasoning that metal-poor systems implies young system…
- metafunctor 3y ago
  Here, “young” means measured from the Big Bang. Our sun is made from the stuff of previous stars.
- codeflo 3y ago
  I’m assuming the poster misspoke and meant that metal-poor stars have formed when the universe was relatively young, not that the stars are young. It’s also my understanding that a planet such as ours could only have formed a bit later, after enough supernovae had formed all the carbon and iron and so on that we need to live.
  - Sharlin 3y ago
    Making matters confusing is the fact that the phrase "a young galaxy" is commonly used to refer to a galaxy formed when the universe was young – if it’s far away (high redshift, z >> 1) and as such we see it the way it was when the universe was young! This specific study, however, looked for more nearby galaxies (z < 1, we see the light that was emitted a few billion years ago) so these galaxies (as we see them) are in fact "old". I think essentially all existing galaxies either formed >10 Gy ago or are the results of galaxy mergers – so in that sense there are no "young", recently-formed galaxies in the universe at all as the raw material was long ago used up. As such in astro-talk "young galaxies" can fairly unambiguously mean "far-away galaxies". But formally they’d be called high-z or high-redshift galaxies.
  - rbanffy 3y ago
    > after enough supernovae had formed all the carbon and iron and so on that we need to live. And let’s not forget some of the atoms we see around us have been through even more violent events than supernovae. Population II systems must be very boring.

pvg 3y ago

'Metallicity' in that sense is used to describe stars and the Sun, being a relatively young star is metal rich. Edit: 'young' is confusing here as pointed out in sibling comments - young compared to the age of the universe rather than young in terms of stage of stellar evolution. To make this even more confusing, this is 'population I' - younger and more metal rich unlike older, metal-poor 'population II' stars. https://en.wikipedia.org/wiki/Stellar_population#Chemical_classification_by_Baade https://en.wikipedia.org/wiki/Stellar_population#Chemical_cl...

vlovich123 3y ago
Ah ok. So this is about the composition of just the star and not anything about the broader system.
- pvg 3y ago
  Yeah although like most things in exoplanetary astronomy, the relationship between metallicity and planetary systems is an area of active research with various not-totally-intuitive findings: https://www.space.com/31456-rocky-planet-found-unlikely-star.html https://www.space.com/31456-rocky-planet-found-unlikely-star... https://www.nature.com/articles/s41467-023-37195-4 https://www.nature.com/articles/s41467-023-37195-4
  - spookie 3y ago
    That Neptune sized planet sure is close to its star. Interesting
    - pvg 3y ago
      Oh they get even bigger and closer and we've seen a bunch of those because they're more readily detectable: https://en.wikipedia.org/wiki/Hot_Jupiter https://en.wikipedia.org/wiki/Hot_Jupiter
- defrost 3y ago
  Almost pretty much the same thing really. Consider that our sun contains 99.86% of the mass of our Solar System. Bear in mind the headline is about total spectrum of elements in entire galaxies ... eg: as in looking at our galaxy, the entire milky way, from a distance that makes it dwindle to a near point and difficult to estimate how many stars make it up. Of all the many galaxies that we can see, this is a story about a handful that are mostly hydrogen and helium .. more so than what we see as typical for galaxies.

dudeinjapan 3y ago

We have Black Sabbath, Iron Maiden, KISS, Slayer, and Megadeth. I'd say we are doing alright!