# Tag Info

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Differential rotation achieved in global, 3D convection simulations is described by a thermal wind and highly sensitive to the outer thermal boundary condition. . . . The fixed flux (FF) boundary tends to yield more solar-like rotation profiles, while the fixed entropy (FE) boundary yields weaker contrast and negatively tilted contours. Results show that ...

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In a rotating solid body, regions that are adjacent at one point in time will remain adjacent as the body rotates. This means that points further from the rotation centre will travel at greater speeds than those closer in. If the rotating body is not solid, however, regions that are adjacent at one point in time do not necessarily maintain that ...

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The short answer is that the differential rotation is the result of combining convection, viscosity and a global rotation. A ball of honey Imagine you were on the ISS and you had a jar of honey (do not actually try this ;). You take out the honey and make a floating ball of honey. Then you gently star to spin it. You would notice that if at the start you ...

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You basically asked the same question over on Worldbuilding. I'm copying my answer to that question here. This answer does not specifically address the strength of the magnetic pulse because whether or not that strength has any affect is dependent on far too many variables to give you a simple answer (e.g., ground conductivity, ground charge, age of the ...

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The sun is made of plasma, which is a conductive gas. As such, magnetic field lines will get trapped in the plasma and twisted by the differential rotation. Tangles of magnetic field in the sun have produce very powerful magnetic fields. Where these tangles meet the surface of the sun there are active regions that have sunspots and prominences. The breaking ...

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There are several answers to this similar question: https://astronomy.stackexchange.com/questions/42053/what-pulls-the-sun-above-the-galactic-plane-and-pulls-it-below-the-galactic-plan/42054#42054[1] If I remember correctly, it takes tens of millions of years for the Sun to make one full oscellation "above" and "below" the galactic plane, ...

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This is an interesting question! The Sun is a dynamical ball of hot plasma maintaining various types of equilibrium: hydrostatic, thermal, and nuclear. Observations over the last century have improved estimates of chemical abundances in the Sun, but its still an active area of research. The Sun is composed mostly of hydrogen and helium, which has been well ...

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According to Formation of the UV Spectrum of Molecular Hydrogen in the Sun (S. A. Jaeggli et al. 2018 ApJ 855 134, also here) molecular hydrogen in the sun was first spectroscopically discovered in 1977. The model calculation in this reference give a ratio molecular/atomic hydrogen of around $10^{-5}$ at a height of about 650 km (where the $H_2$ emissions ...

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They made star maps. They mapped the posiitons of stars on the imaginary celestial sphere - whch they thought was an actual physical hollow sphere surrounding the Earth at some distance. Because the earth rotates, and they thought that the Earth stood still, they believed that the imaginary celestial sphere rotated around the Earth. They saw that stars ...

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There's nothing wrong with asking a question to which the answer is "nobody knows" -- so long as you are willing to accept that the answer is essentially "nobody knows". The only thing we do know is that the probability you are asking about is non-zero because life does exist on the Earth. Some argue that the probability you are asking ...

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That argument seems correct. A calculation by timeanddate.com would suggest that the day is about 9 seconds longer in Kazan than in Moscow on the 23rd of September, consistent with your prediction

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The answer is, it could be non-zero (some would argue it must be non-zero), but since we don't know what the probability of life emerging on Earth was, it is impossible to quantify. This is why this question is normally turned around - if we find life elsewhere in the Solar System (and it is independently developed), then what is the probability that life ...

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What I am actually after is to answer more scientifically the children's question: "What happens if I throw something in the Sun?" and my answer was always "It burns." but I am now wondering about the "How does it burn?" It doesn't burn. What happens when an object such as an asteroid or comet impacts the Sun is in a sense the ...

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None of the other responses seem to answer the question "What is the name of the thing the solar filter is eliminating?" In fact, the solar filter doesn't eliminate anything. It just makes everything a lot less bright. The reason the white part of the sun looks so big is due to saturation of the film, CCD, or retina that you're using to look at it. ...

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The part of the sun you see (but you shouldn't look at the sun except through a filter) is the photosphere: https://en.wikipedia.org/wiki/Photosphere The scattering effect in your second photo is due to the atmosphere: it can be anywhere from almost nonexistent (say in clear mountain air) to obscuring the solar disk entirely, as when you have a heavy cloud ...

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Yes... in some ways. The "flames" you can are not like flames from a fire on Earth. They are strongly connected to the magnetic field. The flames are called "prominences" and are composed of loops of plasma following magnetic field lines. A prominence is big, it can reach 800,000km from the sun's surface, but since the Earth is 150,000,...

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The "tongues of flame" I think you're referring to are solar prominences: They can reach heights above the Sun's surface (actually, photosphere) of around 100,000 km (Hyperphysics). The distance to the Sun is around 150,000,000 km. No, they can't reach Earth. However, every now and then the Sun does emit much larger, localised bursts of plasma and ...

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I think you're talking about the effect of a "fluffy glowing ball" around the solar disk, shown on the right in this photo: This is called solar aureole, and it's caused by the aerosols in the air, which scatter light with a well-pronounced forward peak in the phase function: (image source)

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What it the outer part of the sun, that we see with our eyes, called? I am not sure there is a single word for this, since the effect is a little complicated. We might call it "the glare of the Sun". But there are (at least) two things that will contribute to this. Optical and perceptual artifacts created by our visual system and by cameras when ...

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Yes, the Solar System barycentre (SSB) is usually outside of the Sun. That is, over the long term, the mean distance from the centre of the Sun to the SSB is greater than the Sun's radius of 695,700 km. (That's the IAU's nominal solar radius). As ProfRob commented, we don't really know the exact location of the SSB, since we can only calculate it based on ...

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Not a direct answer to your question (which others have given already), but maybe still worth considering here: The dynamics of the solar system can to a high degree of accuracy be calculated by assuming the sun and planets as point masses, so whether the barycenter lies inside or outside the defined surface of the Sun is physically not really relevant for ...

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The Sun's motion relative to the Solar System barycenter is dominated by the four planets Jupiter, Saturn, Uranus and Neptune. Neptune is a lot lighter than Jupiter but it's also a lot farther away, and contrary to intuition the farther out it is the larger the induced motion in the Sun around the barycenter. *To first order we can treat the Sun's response ...

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It would exapand and cool. The sun's surface (however that is defined) is a mixture of hydrogen and helium plasma in a ratio of about 3:1. It is plasma because it is hot. If you moved some to somewhere cold it would cool down. There is no magic in this, it is essentially the same as a hot cup of coffee cooling down. As it cools it would return to being gas, ...

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Plasma is extremely hot gas. In the sun it is compressed by the high gravitational forces. Therefore nuclear fusion is possible. If the plasma would be taken out it would expand and cool down. It would definitely not stay plasma as there would not be enough pressure and heat. As the nuclei cool down they would "take back" their electrons and ...

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Note that the Sun here is point-like and there is no refraction. What have I done wrong? Your supposition that the altitude of the Sun is directly related to the length of the day is wrong. Proof with counterexample: observe the altitude of the Sun on the equator and in the Moscow on the equinox; but still, the lengths are the same. And what is the correct ...

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The current solar constant on the frost line is equal to: $$j_c=\frac{\sigma T_c^4 \cdot 4\pi r_c^2}{4\pi R_c^2}=\frac{\sigma T_c^4 r_c^2}{R_c^2}$$ where $T_c$ is the current effective temperature, $r_c$ is the current radius of Sun and $R_c$ is the current distance of frost line. We write the equation for solar constant on the frost line when the Sun is a ...

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Some of the comments here seem to be suggesting that there should not be any residual charge of the Sun at all because of the fact that in a conducting medium no electric fields can exist. This argument ignores the crucial point here, namely that there are unequal numbers of positive and negative charges, because electrons, unlike ions, can easily escape ...

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When all we have is a hammer, sometimes we run the risk of thinking everything is a nail - and sometimes that naivety can lead to new discoveries in lieu of better explanations/theories. In terms of surface activity of the Sun, if solarspots, Ellerman Bombs, solar flares and coronal mass ejections are examples of nails, then magnetic reconnection is the ...

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