All Questions
5 questions
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How rare are nebulae which emit H-Beta/H-Gamma/H-Delta? (Balmer series) [duplicate]
Most of the visible light emission nebulae have a lot H-alpha emissions, and because of that appear red.
But why are other Balmer emissions much rarer? Do they need a hotter environment which is ...
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Star forming regions
Some star forming regions, like Bok globules (which contain stars that still haven't dispersed their molecular hydrogen and cosmic dust shell) appear dark compared to the rest of the H II in which ...
- 716
3
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Hydrogen Frost Line? Where, if anywhere, is it cold enough for Oort Cloud objects or rogue planets to have solid hydrogen on their surfaces?
I like the idea of Oort Cloud objects all being crusted with a thin layer of hydrogen snow, though what little information I've managed to find on the topic seems to imply that that is unlikely, ...
- 241
5
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Why does hydrogen ionization happen in HII regions?
Why does hydrogen ionization happen in HII regions? Why is the hydrogen there ionized?
- 665
3
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What are the implications if the Sun was formed in a warm nebula?
Molecular oxygen O2 has been found on comet 67P/C-G in a ratio of 3.8% to water, which is much higher than expected. An explanation proposed is that the Solar System formed from a molecular cloud ...
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