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.

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Power radiated by the Sun at different locations [closed]

I am wondering can someone help to solve second part which extends first part; The power radiated by the Sun is ${3.9*10^{26}}_{watt}$. The earth orbits the sun in a nearly circular orbit of radius $...
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Coronal heating problem -How deep does it go?

On the top of the list of problems in solar physics we find the coronal heating problem. The Corona is the outer plasma atmosphere of the Sun, with a temperature of 1-5 millions of degrees Kelvin, ...
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What happens to the electron companions of cosmic ray protons?

If primary cosmic rays are made mostly of protons, where are the electrons lost, and does this mean that the Earth is positively charged? Does the sun eject protons and electrons in equal number?
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Why does the moon look bigger at the horizon? [duplicate]

Possible Duplicate: Why does the moon sometimes appear giant and a orange red color near the horizon? Why does the moon look bigger at horizon or skyline than at other times e.g. at moonrise and ...
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How to create unusual sundial?

I am considering small "artsy" project. I would like to create sundial by placing gnomon on the window and painting hour lines on the window facing wall. Since this is to be placed in bedroom I am ...
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Is there any way to anticipate exceptional Aurora Borealis viewing conditions?

I've always wanted to see the Aurora Borealis, but never had the opportunity, since it is so rarely visible in my area (Pennsylvania). However, last week was apparently a rare opportunity of ...
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Is a water world possible, and for how long could it be stable?

I have several questions regarding this topic. First, could a water world be stable for thousands of years with most of its surface remaining covered in water. What would it take for this to be ...
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Force on Earth due to Sun's radiation pressure

I have been asked by my Classical Electrodynamics professor to calculate the force that the Sun exerts in the Earth's surface due to its radiation pressure supposing that all radiation is absorbed and ...
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How far from the Sun is a photovoltaic effective?

Just what the title states. Photovoltaic cells convert incident light to electricity; this probably means they create less electricity when it is dark - as in deep space. How far can a solar cell ...
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Finding radius of Earth through observation of Sun's motion

The question I'm about to pose is from a physics book I had recently bought. Since I am very interested in physics I am quite keen in understanding how this question can be solved. Before I present ...
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Could we survive if the Sun were a black hole? [closed]

Ignoring the impossibility of the sun suddenly collapsing, and the energy release (which would kill us): If the sun suddenly turned into a black hole, could we survive if we had sufficient energy for ...
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Solar neutrino Spectrum - Why are there discrete energies for Be and pep?

What is the reason why some reactions give a continuum for the energy of the released neutrinos and others give only a discrete value ($\ ^7B$ and $pep$ )? Thanks for your help. Please feel free to ...
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What's wrong with this temperature-in-space calculation?

I'm trying to calculate the steady-state temperature of a body in space, but my numbers are coming up much too small. For example, for a 1-meter cube, I'm getting a temperature of 194 K (or -81 C). ...
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Duration of Satellite orbit in the shadow of the Earth

I want to determine how many minutes a satellite is in a circular orbit around the Earth at about $1000 km$ altitude. I assumed that the Sun-Earth vector lies exactly in the orbital plane of the ...
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Steady State Temperature of an Object Orbiting the Earth

This may be irrelevant or stupid to ask but I couldn't come up with a good answer. At least, we could not agree on with my friend the other day. I would like an estimate of the temperature of a human ...
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How to calculate max temperature craft needs to withstand near the Sun

The Solar Probe Plus fact-sheet states that the craft will approach to the distance of 9 solar radii to the surface of the Sun (Approx 6.26e6 km) and its heat shields must withstand 1644K of heat. I ...
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What percentage of sunlight isn't scattered by air molecules?

The sky looks blue because of scattered photons. Our Sun looks often yellow because the photons we receive in ours eyes 'are' yellow. Now is the yellow light we receive in our eyes when looking ...
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Neutrino beam energy

Neutrino is one of the most mysterious particles in todays physics. Even when values of some parameters like for example mass associated with it are not known (or there is great range of possible ...
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Does the sun have angular momentum?

The sun was formed like this: Clouds of dust and gas were moving and so this cloud of gas and dust pulled together its particles by the gravity of these particles. Since this cloud used to move in ...
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Does brown but transparent swimming pool water heat significantly faster than western style highly chlorinated pools?

Eastern European swimming pools are often brown tinted water. i was told it was the color of the chemical to keep the pools clean, but who knows. These pools did not smell unsanitary and may have even ...
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Solar Neutrino Problem [closed]

I am not sure if this has been asked recently, but has there been any headway into solving the solar neutrino problem? I recently completed the Particle Physics for non-Physicists by Professor ...
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How much of Sun's mass is “regular” matter? How precisely do we know Sun's composition?

This is a question which spun of this Can the Sun / Earth have a dark matter core? I have argued that it is possible to pretty accurately estimate how much mass of Sun is in the regular matter, so ...
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Is there any metal or any material that can survive the Sun? [closed]

If we were to send a unmanned spaceship through the Sun. What material can survive?