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Questions tagged [the-sun]

Questions regarding the closest star to Earth, at the centre of the Solar System.

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The reason why the Sun doesn't explode? [duplicate]

I know that the Sun is made up of hydrogen and helium. Also, hydrogen explodes when it touches a flame. But why does the Sun not explode?
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1answer
47 views

What does the Sun look like from the heliopause?

I calculated the angular diameter of the Sun at the heliopause to be 0.004°. If that is correct, would the Sun appear as a disk, or like the pinpoint of light from a star? How bright would the ...
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1answer
84 views

Could the Sun have liquid iron in orbit?

How close of an orbit to the Sun could an iron meteor get before it melts into a ball?
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35 views

Angle between earth's angular momentum and earth's axis

I think this picture is correct because for earth astronomical day is slightly shorter than solar day. (Is it a rule of thumb for planets? Where can I read such data?) Source So the angle between ...
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1answer
63 views

Does the Sun's atmosphere have a scale height?

Much of the Earth's atmosphere has a scale height $h$ of roughly 7 to 8 kilometers such that the local density varies as $\exp(-(r-r_0)/h)$ where r is the radius vector and $r_0$ would be some ...
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Why does the sun have a convection layer and a radiation layer?

Why is the outer section of the sun convective but the inner section stable and only radiative? They are both made up of the same kind of matter, both heated by the core.
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Sunset on [Mountain] from [Viewing Point]

How do I get the days in this year when the sun will set exactly on top of Fuji as viewed from Enoshima. I shamefully admit that I just want to take a nice picture of Fuji.
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1answer
5k views

Why does the Sun have different day lengths, but not the gas giants?

The Sun's rotation period varies from about 25 days at the equator to about 38 days at the poles. As I understand it, this is because the Sun is not solid, and because of the way centripetal force ...
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Why doesn't the fusion process of the sun speed up?

Am I correct in saying that the fusion process of the sun is constant, i.e. X amount of fusion happens per day, more or less? Why does this not speed up, i.e. one fusion event creates energy for two ...
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1answer
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Can the Sun pull an iron asteriods in it's orbit into it? [closed]

Can our Sun's magnetic field strengthen in any way in a short period? Can the Sun pull anything trapped in close orbit around it? What would happen if an object in orbit passes over a sunspot for ...
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Did OSO-3 or any other spacecraft or ground telescope record the solar activity that is likely the cause of the May 1967 aurora?

The question What solar event caused massive aurora borealis in the mid 1960's? reminds me again of a stunningly bright aurora that I saw circa 40°N circa 1967, and after reading the comments and ...
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Definition of the light that is projected by a celestial body/luminary [closed]

I'm creating an application which will simulate the light created by sun or moon on a 3d topographic map of Earth. Something like this: Is there a word or definition for this light/light projection?
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1answer
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Does the Sun twinkle?

Does our solar system have enough bodies in orbit to appear to twinkle to another distant solar system viewed from the side? https://en.wikipedia.org/wiki/List_of_asteroid-discovering_observatories ...
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1answer
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Solar azimuth for celtic fire festivals

I am pretty new to astronomy, and I have fallen down rabbit hole creating a new Metonic calendar in Javascript. As part of this I would like to calculate when the sun is half way between a solstice ...
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First observation that the Sun and Jupiter (and friends) move around a common barycenter?

Answers to the question How did Kepler determine the orbital period of Mars? describing careful observations centuries ago got me thinking. What was the first analysis of observations that directly ...
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1answer
56 views

Historical Distance of Planets to Earth [duplicate]

I'm curious if there is a readily accessible tool available, or simply a reliable way to find out what the distance of the planets in the solar system were on a given date. For example, if I am ...
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3answers
210 views

Why do sun spots appear near the equator of the Sun?

I noticed on many examples sun spots are near the equator of the Sun. Why are there no sun spots closer to the poles of the Sun?
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1answer
67 views

Is there a plausible causal mechanism to explain why the Sun would be heating up faster/ sooner than we thought? Question for a novel [closed]

I am writing a novel about what it will be like on earth 500 or so years before the death of our Sun. The Sun is heating up gradually and one day that will negatively affect life on Earth. I know that ...
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1answer
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How do we know if an object is redshifted?

I have some questions about redshift. I think that the first two hang on the last two, but feel free to point out anything you think I should know. How do we know if an object is actually redshifted,...
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1answer
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Are there any ways in which the light time difference between the center and the edge of the solar disk is noticeable?

In the ABC News video New space discovery has astronomers buzzing at about 02:30 Dr. Hakeem M. Oluseyi explains that the shortness of FRBs (before dispersion) suggests a compact source size and ...
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Did Eudoxus describe the eclipitic on his sun motion model?

In the description of Eudoxus’s model for the sun he says one the three circles which describe solar motion is “the circle which runs along the middle of the zodiac”. Does this refer to the ecliptic ...
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1answer
87 views

Geographical Point of the Sun

I want to draw a Sun in a 3d scene, so I figured the easiest way would be to calculate the latitude and longitude of the point perpendicular to Sun position and then just move it "up". As a starting ...
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1answer
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Do we know if there are asteroids leading or following Earth in Earth's orbit around the Sun?

A search of the Internet is so clouded with discussions about the asteroid belt or asteroids orbiting the planet Earth that I couldn't see an answer to my question. Do we know if there are asteroids ...
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2answers
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How fast will the sun grow when it becomes a red giant?

We all know that our sun will become a red giant in a couple of billion years? But how fast will the process be when it starts? Would it be theoretically possible (disregarding the deadly effects of ...
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Looking for a 3D animation showing the motion of the sun relative to other stars and the Milky Way, any one seen anything like that?

I am looking for an animation that not only shows the inclination of the solar system respective to the plane of the galaxy, but also shows the motion of the sun relative to and in conjunction with (i....
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2answers
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Why is it that night has a almost a bluish tint to it instead of red?

From my understanding/been told, the color red has the ability to travel the farthest in our atmosphere, being the reason why we have red sunsets and such. But with this in mind, why is it that at ...
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2answers
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Would the solar corona be visible from the distance of the outer planets?

If the photosphere was blocked, before the sun rises on an airless moon in the outer solar system, would either the inner or outer corona be visible to the naked eye?
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1answer
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Would one have to be more than halfway to the Oort Cloud for the Sun to appear as bright as the full moon?

Is this correct? If the Sun is 400,000 times brighter than the full moon am I correct in figuring that one would have to be about 632AU from the Sun for it to appear as bright as the full moon. If ...
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0answers
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Can you go blind if you look at the sunrise and sunset? [duplicate]

Everyine knows its dangerous to look directly at the sun, but can you look safely at sunrises and sunsets without going blind? Because the uv radiaton and the light is much weaker. Or is it still very ...
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1answer
47 views

Which side of earth will face toward sun when earth and sun will be get closer and be bonded by Gravitational Force? [duplicate]

We all know that one day the distance between the Earth and the sun will be zero. They will be bonded with gravity. My Question is which side of the earth will face toward the sun? I can't calculate ...
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0answers
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What should be the seperation between sun and moon during a solar and lunar eclipse as viewed from earth?

I saw this code online where a guy calculates the separation between sun and moon and verify the occurrence of eclipses. You can find the codes here. Why does he uses earth's angular size seen from ...
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2answers
135 views

Calculating the sun’s position in ECI

I’m trying to calculate visible ISS passes and I need to calculate if the ISS is behind the earth by “drawing” a line between the ISS and the sun and seeing if it crosses earth. I have the ECI ...
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1answer
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What would the sun look like from aphelion of The Goblin's orbit?

I was amazed to find out about the discovery of The Goblin 2015 TG387 with an orbital period of more than 32 thousand years and a aphelion of more than 1955 AU! That is an astonishing distance. What ...
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What is the great (platonic?) year? How could it be explained in laymen's terms?

How could a great year be explained in laymen's terms? According to the definition in NASA's Aerospace Dictionary it is a complete cycle of the equinoxes around the ecliptic that completes in 26000 ...
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2answers
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What is meant by sun's path through zodiac

I read somewhere that sun's daily course and complete cycle is visible in the ecliptic belt by zodiac constellations. I didn't understand what that means closest I could find online is: https://www....
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3answers
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In which direction is the sun travelling?

Relative to this simple drawing, can someone explain to me, in which direction is the sun and its solar system travelling, which star (irrespective of distance) is closest to that direction, and in ...
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1answer
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How to get the solar zenith from the longitude and latitude?

I have real data of “Direct Normal Irradiation” and “Diffuse Horizontal Irradiation” and I should calculate “Global Horizontal Irradiation”. I have also longitude, latitude and elevation. Could you ...
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2answers
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How does the Sun orbit the Sun-Jupiter Barycenter?

I got the Orbital Elements of Jupiter around the Sun, which describe how it orbits relative to the "fix" Sun. Jupiter Semi Major Axis (AU): 5.20336301 Eccentricity: 0.04839266 Inclination to ...
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2answers
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A few questions regarding the transit of planets

Here we will be concerning ourselves with the transit of a planet with it's parent sun. I have a few questions that I am not sure about: 1) Do all planets transit their parent sun? It would seem to ...
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1answer
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Mars vs Venus: the retention of atmospheres in relationship to Earth

Correct me if I'm wrong, but the factors than enable a planet to retain or lose an atmosphere seem to be: 1. Magnetic Field, 2. Solar Winds, 3.Weight of Gases, 4. Planetary Temperatures. 5. Distance ...
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3answers
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Why does earth's north pole roughly point in the same direction throughout the year?

I know there is a gioscopic explanation but I was under the impression that Earth is traveling in a straight line through space that has been curved by our sun's gravity ,so my question is why doesn't ...
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1answer
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When are the planets occulted by the sun?

There are numerous lists available of past and future planetary transits and occultations, but I can't find any that list transits behind the sun. Do the planets in our solar system ever pass ...
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2answers
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How far can you see in solar plasma at just under 1 solar radius?

I was trying to compose an answer to this question here, about touching the surface of a star, and I was going to mention that the popular depiction of the sun's surface as 'basically lava' (as ...
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How does the geometry for constructing a declining vertical sundial work?

I understand how to construct South-facing vertical an horizontal sundials and the geometry behind their construction by projecting an equatorial sundial into a plane, but I can't quite get how to do ...
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3answers
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Sun's Stellar Class at Birth?

The Sun currently has a stellar class of G2V. However, since its birth, the Sun has brightened significantly. What would the Sun's class have been when it was born ~4.6 gyr ago?
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Sunrise - from earth - sun position or when sun rays reaches earth?

Time for the sun rays to reach earth is approximately 8 mins. If time of the sun rise is 7:30 - which time is this? Time when sun rays reaches earth or time when earth and sun comes into correct ...
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Can one detect from earth that angular momenta of its axial rotation and its orbital rotation are “almost parallel”?

I mean that the angle between these angular momenta is acute as opposed to obtuse (23.5 and not 180-23.5), so that the rotations are "roughly in the same direction". Related but distinct question -- ...
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1answer
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What is a “semester series” for eclipse prediction? - Solar saros series 147 and 152

Yet again, I just stumbled across another baffling eclipse question (actually, two now). I was interested in two eclipses (Saros series 147 and 152) that will both be occurring in 2021. Each of these ...
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2answers
154 views

Remains of the progenitor of the Sun

It has been argued that it is not possible to trace back the remains of the progenitor star of the Sun (sometimes called Coatlicue), which, being estimated in the mass range of 30 $M_{\odot}$, should ...