Questions tagged [metal]

Any element other than hydrogen and helium is considered a metal by astronomers.

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3
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1answer
55 views

Why could Quasi-stars (“black hole stars”) have only existed when everything was hydrogen and helium? (no metal “contamination”)

This informative answer to What was the absolute limit to the possible sizes of the first stars formed from “primordial material with no metals”? led me to Wikipedia's Quasi-star; Formation and ...
26
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1answer
4k views

Is lithium considered a metal in astronomy?

My lecture notes are conflicting on this issue so I seek definitive clarification. In Astronomy, are metals either A: the elements which form within stars (i.e., not Big Bang nucleosynthesis, where ...
3
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2answers
431 views

How do astronomers detect the 'metals' in a star? If the atoms are presumably completely ionized?

Atoms and molecules usually emit their characteristic wavelengths because of the electrons' energy levels.... Do the completely ionized ('naked') nuclei absorb and/or emit EM radiation? If so, at what ...
3
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0answers
38 views

What is the etymology of the astronomical term metal [duplicate]

It's well known that Astronomers use the term "metal" to describe any element heavier than Helium but could anyone tell me why? What is the history of this particularly strange bit of language?
11
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3answers
556 views

Why can't a quasistar exist now?

From my research, I found out that quasistars theoretically existed because of a black hole core whose radiation pressure counteracted gravity within the star. However, a few websites stated that ...
4
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2answers
2k views

Does Gold really come from Supernovas? [duplicate]

Do we really know that the origin of gold was in a supernova explosion? I am talking about the gold we find here on Earth. So then how are we sure that Gold actually came from these explosions. Did ...
5
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2answers
622 views

Why are stars more metallic closer as you move closer to the galactic bulge?

As I see it, most of the stars in the galactic bulge are Population I stars. However, as one moves farther from the galactic bulge, star metallicity decreases. In fact, halo stars are almost entirely ...
8
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1answer
834 views

What are the most valuable meteorites and asteroids in terms of precious metals?

There were some suggestions that asteroids could one day be mined for precious metals. I have found an outdated study that says that some siderites contain as much as 0.001% of gold: http://pubs.usgs....
8
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2answers
2k views

Why you use log to measure metallicity in galaxies?

For example, I saw the next expression for matallicity in a paper: $\log(O/H) + 12$. I understand O/H is the O(Oxygen) to H(Hydrogen) ratio but why is there the number 12? And why the logarithm?
3
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0answers
218 views

If two pieces of the same type of metal touch in outer space, they will bond together permanently? [closed]

Is this true? And if so, why? http://www.snapple.com/real-facts/cap-view/1003
5
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1answer
237 views

Is metallicity low at the central region or nucleus of the Milky Way?

Is metallicity low at the central region or nucleus of the Milky Way? Does metallicity decrease or increase as we move from the center out to the edges of our galaxy?
5
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0answers
63 views

What is the reason for the dispute over the variation of core mass with heavy metal abundance?

In Metal-Poor Stars IV: The Evolution of Red Giants, Rood writes The differences in the results of these papers are large enough to introduce appreciable uncertainties into the study of the ...
6
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3answers
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Metal distribution in our solar system

The sun dominates in our solar system. I wonder whether in every aspect the sun plays the most important role in our system. For example, all kinds of metals are mainly located in the sun instead of ...
1
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1answer
246 views

Where/how are metals distributed in our universe?

For one particular kind of element, what is the distribution in the whole universe? Are most of the metals located in ISM, IGM, or stars? Maybe different metals have different distributions? For ...