Questions tagged [opacity]

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5
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1answer
98 views

What class of elements are providing the many electrons needed to make the H- ion?

Continuous absorption by the H- ion reaches its maximum in the cool atmospheric layers of G stars. At these temperatures, most of the hydrogen atoms are neutral; but what class of elements is ...
60
votes
2answers
11k views

Is it dark inside the Sun?

This might sound like a strange question, but something got me thinking about it recently. The opacity of plasma in stellar interiors can get quite high, making for shorter free-paths for photons. In ...
6
votes
2answers
85 views

How far can you see in solar plasma at just under 1 solar radius?

I was trying to compose an answer to this question here, about touching the surface of a star, and I was going to mention that the popular depiction of the sun's surface as 'basically lava' (as ...
2
votes
1answer
152 views

What leads to increase in opacity in kappa mechanism?

I understand that the kappa mechanism (that leads to star variability) causes an increase of opacity with increasing temperature in partial ionization zones. However, I'm not sure I understand what ...
3
votes
1answer
154 views

What is the main source of opacity in sunspots?

In the first version of my answer to Are sunspots vertically displaced from the surrounding photospheric plasma?, I naively used Kramer's law to attempt to show an inverse relationship between opacity ...