New answers tagged star
2
votes
Is there a easy way to read a star map and discover when and where it was seen and recorded?
Not an "easy" way.
The stars don't move relative to each other enough to make their relative positions useful for finding the date. And the absolute positions of the stars repeat each year, ...
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0
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Confusion over habitable zone
You should take the inner and outer edges of the habitable zone of the Sun as your model. You say your star has luminosity of 20. If that is 20 times the luminosity of the Sun, there is a ...
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13
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Confusion over habitable zone
The reason you get a too cold temperature for Earth is of course because you ignored the greenhouse effect. The atmospheric composition strongly affects the actual temperature of planets, which ...
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2
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Does most of the Sun's energy and light come from its black-body temperature, due to its massive size alone? Constant crashing of particles?
If you calculate the total thermal energy of the Sun now - i.e. the sum of the thermal (kinetic energy) of its constituent particles - then it could be used to supply it's current luminosity for 40 ...
- 141k
2
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Does most of the Sun's energy and light come from its black-body temperature, due to its massive size alone? Constant crashing of particles?
A collapsing cloud of gas will generate heat from the release of gravitational potential energy, and it's core temperature will continue to rise. Indeed this is the mechanism that Kelvin and Helmholz ...
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7
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Did the Sun's light always peak in the green wavelengths?
One more reference for why plants are green is Quieting a noisy antenna reproduces photosynthetic light harvesting spectra (2020). They compute the optimal absorption frequencies for a noise-...
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12
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Did the Sun's light always peak in the green wavelengths?
No, but that's not why plants reflect green light
The Sun, as well as the light of nearly all stars in the universe, had their peak wavelengths shift at some point during their life.
In the case of ...
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13
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Did the Sun's light always peak in the green wavelengths?
Nice question! Sun's spectral peak wavelength is currently 483 nm which falls under the category of green.
Sun's wavelength changing
In it's early days, the Sun was a lot cooler than it is today. So ...
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2
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Laser pointers spotter
This is poor dark sky etiquette. Even when you're "by yourself", the laser is visible from a long way away (miles away sometimes). And you can't possibly know who's doing what in the ...
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2
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Laser pointers spotter
It depends on national, state/provincial/territorial, regional, or local jurisdiction. Not knowing where you live (though from your name, I would guess Eastern Europe), I would stay on the safe side ...
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