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Questions tagged [metallicity]

In astronomy, metallicity is a measure of how much of an object is made of elements besides hydrogen and helium.

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Why is the Sun made of light elements only?

Since the entire solar system inherits its heavy elements from supernovae unrelated to our star, I fail to understand why, while capturing most of said system's matter, the sun only contain light ...
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Why does the Drake equation never account for the abundance of the elements in the universe?

The Drake equation which is used to describe a rough estimate of possible ET civilizations that is able to communicate with us does not take into account the abundance of the chemical elements in the ...
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How is the primordial abundance of Lithium measured?

I was reading about the "Lithium problem" and I came across this Physics SE post: Discrepancy problem in lithium? The answer mentioned On the other hand, measurements of the $\rm Li$ abundance ...
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When will hydrogen no longer be the most abundant nucleus?

In a recent question, we learned why hydrogen is currently the most abundant nucleon or element in the universe. Here I ask a follow-up: For how long will hydrogen be the most abundant nucleus? It ...
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Age-metallicity-extinction-redshift degeneracy

I'm studying astronomy and astrophysics (particularly Star Formation) and I ran into a problem. There is this mention of the age-metallicity-extinction-redshift degeneracy which I don't quite ...
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Could quasars produce elements heavier than oxygen?

I have read that supernovae are the main producers of elements heavier than oxygen. I just wonder whether quasars, which have been around a long time just like supernovae have, could have had a ...
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Could there be a rocky star, made from silicon, oxygen, etc?

Rocky in terms that it will have mostly silicon and oxygen composition, just like terrestrial planets. But not because it runs out of hydrogen and helium, rather it should start it's life by fusing ...
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Compositions of stars at different stages

So I have been trying to find what stars chemical composition is depending on the stage and I have not found anything beyond the "average star" or our sun. For example out the sun and many others ...
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Can elements heavier than iron be present in a star's core?

My understanding is that elements heavier than iron and nickel are not formed in a star but, can heavy elements such as lead and others be present/found in a star's core ? I ask because the following ...
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Is it possible that there are stars working on fission?

Most/all stars are getting their energy from fusion of small atoms like our sun. But is it possible according to the laws of physics that there are stars getting their energy from fission fe with ...
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Stellar classifiaction and metals

I have recently started to study astronomy and there is a thing with stellar classifications I can't get my head around: The colder the star the more absorption lines from metals are present in its ...
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Why do astronomers call all elements heavier than helium “metals”?

I understand that a scientific term need not be constrained by its etymology. But is there some significant reason why astronomers choose to call all elements heavier than helium "metals"? Are ...
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How much of an asteroid mass can be in platinum or rare metals?

There are many articles about the 2011 UW-158 asteroid which will pass earth tonight. The interesting thing about this asteroid is that it is said to contain $5.4 trillion worth of platinum. Many ...
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Discrepancy problem in lithium?

Why is there a discrepancy between the amount of lithium-7 predicted to be produced in Big Bang nucleosynthesis and the amount observed in very old stars?
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Metal-rich star formation

While discussing star formation on cosmological scales with some classmates, we mentioned the breakdown between the different stellar populations via metallicity: Population III: $Z = [{\rm Fe/H}] \...
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Storing a Planet-sized Chunk of Metal Inside a Star

Would it be physically possible to "store" a planet-size or larger sum of metal, say gold or platinum, inside a star by letting it fall to the core? Would it be possible to detect which stars had ...
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How did all of the heavy elements on earth get here?

I have often read that a first generation star went supernova and seeded our solar system. It is well known that stars that go supernova are the source of elements heavier than iron. I guess I am ...
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How to explain the existence of heavier elements in Population I stars and in Population II stars contain lighter one

Recently I read Astrophysics Notes where I found a statement that young stars are classified as Population I stars and relatively older one as Population II stars. Population I stars contain ...
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Stellar Activity Cycle versus Metallicity

Our Sun exhibits sunspot max/mins on about a 11 year period. It's a G2 spectral class on the HR Diagram. We know that some stars exhibit "starspot" cycles of various intensities and periods. These ...
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How close are humans to creating gold from other elements?

Gold is made in supernovae. How close are humans to doing that? Or is it even possible to do that unless gravity is absurdly high?
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Age of the Earth and the star that preceded the Sun

One of the great unheralded advances made in the history of science was the ability to determine the age of Earth based on the decay of isotopic uranium. Based on the apparent abundance of uranium in ...
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How many times has the matter in our solar system been recycled from previous stars?

I've got a basic understanding of these facts: The Universe is a little over 13 billion years old. Our galaxy is almost that old. Our solar system is roughly 4.6 billion years old. The heavier ...
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Why the distribution of elements on Earth?

I've been wondering exactly why the elements are distributed the way they are on Earth. The heavier elements have their origins in the centers of stars, or in supernovae. After the death of the stars, ...