Questions tagged [sun]
The Sun is an almost perfectly symmetric yellow dwarf star [spectral class G2V] which is at the center of our Solar System.
812 questions
0 votes
1 answer
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Could we, theoretically, force oscillations in the Sun?
Let me preface this by saying that I am aware of the tremendous absurdity that this would be from an engineering and common-sense angle; I am interested only in the theoretical aspect of this question....
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Was switching to space-based UV data the right choice for solar composition analysis?
In my solar spectroscopy project, I first used visible light data but could only identify common elements. When I switched to UV spectra from SOHO (specifically around the H I Ly 5 line at 93.78 nm), ...
1 vote
1 answer
58 views
Shadow from Direct Sunlight Visibly Brighter When Viewed Through Polzarized Lens?
I searched this site for about 10-20 minutes using both Google and its built-in search. Wasn't able to find any question similar to this one. I've taken Physics 1+2 and an introduction to modern ...
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1 vote
0 answers
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Difference between graphing spectral irradiance by frequency versus wavelength [duplicate]
This web page includes two graphs, one of which shows the sun's spectral irradiance as a function of wavelength and the other as a function of frequency. On the first graph, the spectrum "peaks&...
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1 vote
1 answer
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Do solar flares give clues as to how to control hot patches of plasma in nuclear fusion reactors?
In nuclear reactors hot dense plasma regions can rapidly expand and cause the plasma to hit the side of the reactor. Solar flares containing plasma are regularly ejected from the sun. Can nuclear ...
user439184
1 vote
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Gravity from Earth and Sun at noon and midnight [duplicate]
At noon the sun and the earth pull the objects on the earth surface in opposite directions at midnight the sun and the Earth pull these objects in the same direction is the weight of an object as ...
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10 votes
2 answers
2k views
Sun turns blue when seen through a crossed polariser/analyser
It was sunset, and we were looking at the sun through our polariser/analyser setup. When the angle between P and A was zero, the sunset looked normal (albeit with an expected reduction in brightness). ...
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2 votes
3 answers
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Is there a reason that spectral lines are in the range of most Sun's black body radiation peak?
Our star acts as a black body of ~6000K. Conveniently, the range of light that it emits has many transitions of common molecular electron shells, which makes spectroscopy a thing, and also allows us ...
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2 votes
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Normalising spectra
I have a bit of a connundrum concerning some stellar spectra (sun) I obtained from a lab session at my university (with a CMOS camera), where we underwent pixel-wavelength calibration of the spectra ...
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3 votes
1 answer
191 views
Why do pairs of Wavelength and Spectral Irradiance Deviate from Planck Curve?
Below is a graph of spectral irradiance vs. wavelength for NASA SORCE SIM data. I wrote a Python script to create this graph and a corresponding graph of cumulative spectral irradiance vs. wavelength, ...
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2 votes
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How does the radius of a red giant scale with the mass of its envelope?
When the Sun reaches the end of its main sequence lifetime, hydrogen burning in the core will stop. This will make the Sun's radius expand hugely in its red giant phase, as the helium core maintains ...
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The exact formula for calculating solar intensity based on Sun's altitude
I would like the correct, exact formula that will calculate solar intensity for me based on the sun's altitude. The formula proposed in many sources, like for example here: https://en.wikipedia.org/...
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Converting solar irradiance to the visible light spectrum depending on solar altitude
I want to compute the brightness in LUX based on solar irradiance depending on the Sun's altitude above the horizon. I used the formula, which is here: https://www.pveducation.org/pvcdrom/properties-...
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Correct convertion of solar constant to LUX illumination
I became uncertain by converting the solar brightness LUX into the W/m2. My lack of understanding comes from the situation in which the unit of 1W/m2 corresponds to 683 or 685 LUX (under a wavelength ...
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9 votes
1 answer
429 views
Nuclear fusion within a star and escape of light
I understand that light photons travel through the layers of stars from the core, and that they start mainly as highly energetic gamma radiation, I also know that it takes hundreds of thousands of ...
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