Questions tagged [the-sun]

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

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28 views

Solution of stellar structure equation for Sun in Convective Zone

Consider the following problem: Sun has a convection zone from $0.7 R_\odot$ to the solar surface, when $R_\odot$ is the radius of Sun. If the matter is marginally convectively unstable and the ...
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Is Jupiter warming the Earth? (Earth, Sun Jupiter system)

If Sun-Jupiter baricentre is outside the Sun, does that mean the Sun is orbiting around that point too right? Then the Sun shouldn't be nearer to the Earth at some point during the Sun-Jupiter orbit (...
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47 views

Path of sun in the sky on a planet with no axial tilt

Some sources online (e.g. this, see section "Effect of Earth’s Eccentricity") claim that if the earth's axis was not tilted, then the analemma would have the shape of an ellipse/oval. I ...
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50 views

What would be the effect of a large solar flare on motor vehicles?

With the solar cycle now leading to an increase in flare activity, one naturally starts to think the effects of a large solar flare heading this way. While major flares like the Carrington Event are ...
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1answer
27 views

What online tools are available to investigate and classify solar eruptions?

I was just casually browsing when I came across a link about at recent solar flare. So I went to investigate at SpaceWeather. There it was stated: Looking further down the page it seem to say that ...
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1answer
150 views

Is the claim that the star Sirius does not precess like other stars true?

There is this popular claim on Internet that the star Sirius does not precess like other stars. The idea comes from mainly Greeks and Egyptians using Sirius to track seasons, as part of the Sothic ...
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2answers
146 views

What was the day of the week for the total lunar eclipse (saros 61) that occurred on April 14, 32 AD?

I am interested to know if there is convincing "astronomical" evidence/data to pin down the exact day of the week for the total lunar eclipse of April 14, 32 CE. I am hoping that perhaps ...
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1answer
50 views

When could solar eclipse happen in a way that Sun's disk is diminishing from below?

I'm trying to solve this task: During a solar eclipse, an observer noticed that the diminishment of the Sun's disk began directly from below. Where and when could this be? Concerning "where&...
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1answer
143 views

What would happen if the Sun, Moon and Earth were isolated?

I am curious to know what would happen to Earth and life on Earth if all other heavenly bodies outside of our Sun, Moon and our planet Earth ceased to exist in some non-destructive way? (this includes ...
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What is the exact reason for the Sun's differential rotation to occur?

The following is an excerpt from the Wikipedia article for "Differential Rotation": Differential rotation is seen when different parts of a rotating object move with different angular ...
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1answer
37 views

Solar Rotation Varies with Latitude. Effects?

From the Wikipedia article of "Solar Rotation": Solar rotation varies with latitude. The Sun is not a solid body, but is composed of a gaseous plasma. Different latitudes rotate at ...
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1answer
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What would be the effects of a -400 nanotesla geomagnetic storm on modern electronics? [closed]

After reading the Wikipedia article on geomagnetic storms, I'm curious about what the effects of a -400-nanotesla-minimum geomagnetic storm would be on modern military and consumer electronics. The ...
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1answer
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The Sun's motion around the galaxy [duplicate]

As the Sun orbits the Milky Way, I understand that it also moves up and down through the plane of the Galaxy. How long does this movement take and can we tell where we are in the current cycle.
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219 views

Is there molecular hydrogen in the Sun's atmosphere? If so, how much, and how was that first determined and measured?

I don't have a license to practice chemistry, but I'll convert Wikipedia's bond dissociation energy of 435.7 kJ/mol to eV by dividing it by $C / N_A$ where $C$ is 1 Coulomb and $N_A$ is Avogadro's ...
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1answer
123 views

What is the percentage of ortho- vs. parahelium in the sun?

Parahelium (P) has its 2 electrons with opposite spins and S=0. Orthohelium (O) has parallel spins and S=1. The energy levels of P are a little bit higher than O. Maybe this leads to easier building ...
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1answer
105 views

How did the ancients know the constellation in which the sun is located?

The zodiac constellations lie along the plane of the ecliptic. In Spring equinox, sun lies in Pisces constellations. So Pisces is not visible during the day (because the sun light) and not visible in ...
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1answer
95 views

In which town is the length of the day bigger on 23 of September?

I'm trying to solve this task: Moscow and Kazan are located on the same parallel. In which of them the length of the day is bigger on 23 of September? In Kazan the sun will rise earlier, because it'...
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What is the probability of life having developed or going to develop in our solar system another time?

I'm sorry I am not quite sure this question satisfies this point: Questions that are purely hypothetical, for example a question such as 'Could a black hole destroy the universe' or 'What if our ...
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1answer
86 views

Spectral lines of the Sun?

If I remember correctly, the pp chain and (partially) the CNO cycle are the dominating set of reactions in our Sun. On the other hand, the composition of the Sun has many more elements/isotopes than ...
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2answers
85 views

Is it possible for the Sun to lick the Earth with its flames?

The Sun ejects bursts of high-velocity matter, like fiery tongues reaching out. The Sun's magnetic field is able to deliver these bursts at different spots. Sometimes the flames are pulled back in by ...
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4answers
5k views

What it the outer part of the sun, that we see with our eyes, called?

When we look at the sun with our eyes it seems much larger than it actually is. When we use a solar filter we are seeing what the sun actually is. So, what is the name of the thing the solar filter is ...
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What is the size of the universe? [duplicate]

Will as a result of the continuation of technological progress in the twenty-first century more perfect telescopes or other astronomical instruments that will allow to know what is on the surface of ...
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116 views

If a 1x1x1 Cube from the Sun's surface were scooped , and taken to a sufficiently cold point, say near Jupiter, what would happen to the cube?

Let's assume for the sake of this question that the 1x1x1 cube was scooped by unknown methods, and is instantly brought to somewhere close to Jupiter's orbit without any harm or any change to nearby ...
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3answers
260 views

Is the barycenter of the solar system usually outside of the sun?

I came across this picture on wikipedia: Note: From a quick search I gathered that although there are slight differences between the limb of the sun and the accepted radius of the sun, these ...
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1answer
68 views

Where will the frost line be when the Sun becomes a red giant and what effect will it have on the solar system?

I understand the frost line is currently about 5.2 AU and earlier in the solar systems formation was 2.7 AU. But when the Sun becomes a red giant the frost line should move outward. I understand the ...
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1answer
130 views

Confusion when calculating the length of the day

I'm trying to solve this task: Tula and Moscow are located on the same meridian. In which city length of the day is bigger on 22 of June? 22 of December? I was thinking like that: we need to ...
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1answer
29 views

Strength of the relationship between very large solar flares, coronal mass ejections, and solar proton events?

In the years 774-775 and 993-994, there were large peaks in Earth's atmospheric radiocarbon (14C) concentration. While the cause was initially disputed, Mekhaldi et al.'s 2015 study of annually ...
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1answer
84 views

How big is the Lorentz force on the Sun?

The LOFAR observations have made an estimate of the magnetic field of the Milky Way. The value in our region is very small. About 1/1000 of the Earth magnetic field. The Earth and the Sun move at a ...
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1answer
133 views

What are Ellerman bombs and how can we identify them?

Have you ever heard about Ellerman bombs? Spaceweather.com talks about them on their news page. You could see some of them around sunspot AR2835: Ellerman bombs are magnetic explosions about one-...
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Why doesn't the Sun wobble towards Jupiter instead of away from Jupiter?

This is the page I am referring to. It seems counterintuitive to me that the Sun should be on the opposite side of the barycenter's wobble. I realize I am wrong, but I cannot see why I am wrong. Can ...
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1answer
40 views

Sun right ascension and declination at date with different values on different calculators and also with my implementation

I'm reading the book "Practical Astronomy with your Calculator or Spreadsheet 4th Edition" implementing its formulas with C++. Now, I have implemented formula 47 "Calculating orbits ...
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1answer
82 views

If the sun would be two times as big and with the same power output would temperature on Earth change? [duplicate]

Suppose the suns radius is increased by two. And suppose its emitted power doesn't change. Will we notice this on Earth? It will seem twice as big but apart from that what will we notice(if anything). ...
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322 views

Calculating the position of the Sun

I'm reading the book "Practical Astronomy with your Calculator or Spreadsheet 4th Edition" implementing its formulas with C++. Now, I'm implementing formula 46 "Calculating the position ...
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1answer
400 views

How big is the galactic magnetic field in the solar system and how can we measure it?

The Milky Way has an associated magnetic field. But how big is it influence in the solar system and can we measure it? I mean, when measuring, how can we make the distinction between the field of the ...
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0answers
45 views

What is the sun's maximum influence on a magnetic object?

How much magnetic repulsion could the sun's magnetic field produce on an magnetic object? Consider the object is ideal: It could be flat, to create more resistance, balanced, to stay on the opposing ...
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2answers
91 views

Angle the Sun makes with the horizon during sunset

Let's say it is the day of the summer solstice and the Sun is setting at 23.5 degrees declination. I am at let's say, 10 degrees latitude. How would I go about calculating the angle of the Sun below ...
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1answer
3k views

Why do sunspot rise in number "precisely" every eleven years?

Every eleven years (more or less precisely) sunspots are seen to rise in numbers. The magnetic field of the sun changes polarity over eleven years and this is the reason the number of spots can vary. ...
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Is it safe to look at an annular eclipse during sunrise using a medium

will looking at annular eclipse reflection through a bowl of water damage your sight? i already tried viewing it reflection through a bowl of water.
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1answer
38 views

What is Lawrence Krause's theory of total energies?

Does Lawrence Krauss theory say that the total energy in the universe is equal to zero or that the energy in the entire universe remains constant and the mass in the entire universe also remains ...
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1answer
87 views

Is it safe to look at an annular eclipse during sunrise? [duplicate]

I'm lucky enough to be where an annular eclipse will happen at the same time as sunrise. Usually, it's dangerous to look at an eclipse directly. However, the sun appears much less bright at sunrise. ...
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1answer
60 views

Does the sun have a notable frame-dragging effect on the planets?

Frame-dragging is a general relativistic effect that can be imagined as the effect that the momentum of mass-energy has (the stress elements in the stress-energy tensor) on mass-energy in the ...
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1answer
109 views

Why is the 11 yr sunspot cycle less predictable recently?

I quoted from a similar question on solar minima and maxima. "...I guess the jury is still out, but this is quite "fringe" material. The solar cycle is certainly thought to be a product ...
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3answers
4k views

Is the sun's volume shrinking currently?

The Sun loses about 5.5 million tonnes of mass every second, does this mean Sun's volume is also going down? If so can we tell by how much every year? E: "by how much" I mean can we tell if ...
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1answer
72 views

I made a graph trying to show the Sun's movement relative to the Galactic Plane. It doesn't seem to be correct

I made a Desmos Graph following the most voted answer of this question, but I'm not sure if it is correct, because it suggest that the formation of the Sun happened shortly after it would have crossed ...
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1answer
158 views

Wilson effect: How "deep" are sunspots?

I recently learned about the Wilson effect of the Sun's atmosphere. The 2009 Saas Fee Advanced Course 39 states: Near the solar limb, the umbra [the circular dark region of a sunspot] and the centre-...
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Are sunspots named or individually tracked?

This is a follow-up question to How are the solar flares from May 23, 2021 extraordinary? which is about news of spaceweather.org. In the present question, I am curious solely about sun-spots and why ...
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1answer
42 views

Orbital parameters of the Sun [duplicate]

What are the orbital parameters of the Sun such as orbit velocity etc in it's orbit around the Solar System's center of mass? Consider the Sun pointlike or alternatively when talkin about the Sun's ...
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3answers
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How are the solar flares from May 23, 2021 extraordinary?

The Space Weather News for May 23, 2021 reads (with some highlighting by me) Yesterday, the sun produced a sequence of solar flares unlike anything we've seen in years movie. Earth-orbiting ...
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1answer
191 views

What is meant by "revolution of Sun's apogee"?

While reading Translation of the Surya Siddhanta and of the Siddhanta Siromani(1861) - Bapu Deva Shastri, I stuck in the follwing. Chapter I, verse 41 & 42 In a KALPA (4.32 billion years), there ...
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1answer
94 views

What is the lower limit of a coronal mass ejection?

Reading an 2005 article by Fraser Cain called Smallest Ever Coronal Mass Ejection I became interested in the exact definition of CME. It seems like a simple question - but I did not manage to find ...

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