Questions tagged [the-sun]

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

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2
votes
1answer
51 views

How is magnetic field is generated over the sun?

Dynamo theory suggest how magnetic field generated on Earth. Due to flowing magma which contains molten iron generates magnetic field on earth. But how magnetic field is generated over sun?
0
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2answers
152 views

Is Limb Darkening because at centre we are directly looking core, whereas at limbs we are seeing only photospheric part?

Is limb darkening of the Sun because at centre we are directly looking the core and different zones, whereas at limbs we are seeing only the photospheric part (and less beneath photospheric part)? Or ...
51
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5answers
11k views

Why is moon light not the same color as sunlight?

The light from the moon is light being reflected from the sun. The sun, in space, is white. But on Earth, when the light is filtered through an atmosphere, the light appears yellow. So then, why is ...
3
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3answers
222 views

Will the Sun's solar wind push a permanent magnet out of our solar system?

If you were place a strong permanent magnet into the solar wind, like a 1 inch cube neodymium magnet, would the charged particles of the solar wind colliding with the magnet's magnetic field push the ...
22
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2answers
8k views

Is our sun in a star cluster?

Sorry for the absolute begginer question here, but is our sun a part of some globular cluster? It is something related to Virgo supercluster?
3
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2answers
107 views

Will stars live longer if they consume more hydrogen?

I heard that stars would live longer if they consumed more hydrogen and material from their 'environment'. Is that true? For example, if the sun consumed all of the gas giants, would it live a little ...
-1
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1answer
76 views

Where will the atmosphere of our Earth go if our sun blows it away completely?

What will happen?Will our atmosphere head to the next gravity dominant body?Will our moon hold a part of our atmosphere or is too weak to hold it?Where all those gases are supposed to go?
1
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1answer
118 views

What types of star do we know are hostile to life (like ours)?

Certainly all stars have enough energy for a planet to host life. But a more magnetically active star is not preferred because solar ejection could strip planets of their atmosphere. What's the right ...
6
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1answer
336 views

Why does the Sun's surface contain lithium?

As far as I was aware, stars don't usually have lithium, but it has been observed that there is plenty of lithium on our star's surface. In addition, a team lead by Garik Israelian took a census of ...
1
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1answer
535 views

How was the distance from the Earth to the Sun determined

How was the Earth to sun distance measured. How do we know how far from the Earth the Sun actually is.
3
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1answer
66 views

Apart from Io, will any Galilean moons have oceans and land if their ice melts

When our sun expands earthlings, if still alive, will have to leave. The Galilean moons offer a lot of water but we would also need land. As far as I can tell there will be no land for earthlings to ...
2
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1answer
43 views

Ancient greeks know about leap day? [closed]

I'm reading about Antikythera machine and its functions. So I read about solar cycle and moon cycle and how they used 19 solar years to compare with 235 lunar cycles. So this is my question: They ...
3
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1answer
151 views

Given sunrise, noon, sunset, longitude and latitude can I calculate the “hight” or “ascension” of the sun?

I'm trying to make a simple app for my own use to be able to check which of my favorit restaurants have outdoor seating sun and for how long etc. Given the data in the title (sunrise, noon, sunset, ...
2
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2answers
355 views

Computation of mean sidereal time at Greenwich using solar position algorithm

Using Equation 28 in Section 3.8.1 of Solar Position Algorithm (Reda, I. and A. Andreas, Jan. 2008), I computed the mean sidereal time at Greenwich for 2003 October 17 for four different times (UT), ...
4
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1answer
139 views

What makes an exoplanet to orbit around its star backwards?And why did we consider our orbital movement to be forward?

I read somewhere that an exoplanet in the name of HAT-P-7B orbits its star backwards.Why? And why did we consider our orbital movement to be forward?Is there some scientific reason to consider the ...
2
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6answers
223 views

Would things be exactly the same if the Sun was orbiting the Earth and the Earth was in the center of the Solar System?

Would things be the same if the Sun was orbiting Earth and the Earth was in the center of the Solar System, or would there be any big difference? It seems like why people before thought the Earth was ...
4
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3answers
156 views

Why do we use solar filters instead of simply reducing aperture of the telescope?

Everywhere I read that to view the Sun in the telescope, one has to use a solar filter. The filter must be handled carefully to avoid any holes in it and even mustn't be stretched so as to avoid ...
3
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2answers
3k views

Fate of Jupiter when our sun dies

Five billion years from now, the sun will have grown into a red giant star, more than a hundred times larger than its current size. While this metamorphosis into the giant star will change the solar ...
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2answers
329 views

Why isn't the Sun hollow? [closed]

[Edited to remove incorrect geological assumptions] The sun is self-rotating, i.e. it spins on its axis. When something spins, there's an apparent force away from the centre, and matter gets flung ...
3
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1answer
59 views

Is it possible for a solar flare in one star to influence the chances of a solar flare in another star?

Can a solar flare reach far enough to travel from one ordinary star to another? If so, how can that solar flare affect the following star?
5
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1answer
149 views

Sun's spectrum red shift

Does Sun's spectrum expose any red shift at all? Namely, the center of it's visible area (not due to limb effect). If it does, how much is it and does it comply with relativity theory or is it higher/...
3
votes
3answers
400 views

angle to the equator of the Sun on sky at a given time

Is there an easy way to tell at what angle the solar equator is wrt the horizon at any given time of the day? I would think that it rotates 180 degrees from sunrise to sunset, but not in a linear ...
1
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3answers
220 views

Axial wobble or binary star system

Is our solar system affected by a body unobserved as of yet that causes our solar system to curve through space in an orbit? Is this idea outlandish or us there any evidence to support it? Consider ...
2
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2answers
143 views

absorption line from the chromosphere

If I understand correctly, the H-alpha and Ca II K lines are absorption lines of the sun and allow to see the chromosphere. Following the Kirchhoff-Bunsen law, an absorption line is produced by a gas ...
3
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1answer
196 views

How to calculate the position to be to see ISS passing in front of the moon or the sun?

I would like to know how to calculate the time/date of the ISS passing in front of the moon (between the observer and the moon) or the sun, or to calculate the position in which the observer have to ...
0
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2answers
197 views

When does a star rise with the sun?

Problem: Suppose an observer's latitude is 45 S and a star's RA/DEC is 3h15min/41S. On what date will the sun set with the star. I have been stuck on this problem for a while. I found out that the ...
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1answer
502 views

How to calculate declination of the Sun if its right ascension is known? [closed]

How to calculate declination of the Sun if its right ascension is known? I am BSc (NS) student.
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1answer
300 views

What is the difference between luminosity and absolute magnitude?

I am writing a one page essay front and back about the H-R diagram, I am supposed to describe what is on it and how we use them. But I don't know the difference between luminosity and absolute ...
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2answers
1k views

Sunlight intensity during a day

What simple mathematical function would reasonably well simulate sunlight intensity (disregarding weather) from dawn till dusk in relative numbers, 0-100 %. Are there significant differences (apart ...
6
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1answer
713 views

Effect of the obliquity of the ecliptic / tilt of the Earth on the equation of time

In an attempting to answer the question “why aren’t changes in sunset and sunrise times symmetrical around the solstices ?” I’ve got stuck on being able to explain the effect of the obliquity of the ...
19
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1answer
4k views

How far do we have to go to leave the galaxy?

How far is the sun from the edge of the galaxy in the following directions? Moving along the shortest path parallel to the galactic plane (outward radially) Moving along the longest path parallel to ...
3
votes
3answers
1k views

How close would the sun have to get to Earth for there to be severe consequences?

According to earthsky.org the Earth gets 3 million miles closer to the Sun than its usual distance of about 93 million miles on average. My question is, how close would the earth have to be to the ...
1
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2answers
384 views

Why are the planets moving? [duplicate]

My question isn't why it doesn't have a circular orbit, and why an elliptical, my question is why do they move at all? What caused the debris in space to apply such a force on the planets that it has ...
4
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0answers
193 views

How is Phosphorus made in in stars? [duplicate]

What elements are required to fuse into phosphorus in a star. Can someone give me a step by step process please e.g 4 hydrogen nuclei fuse into one helium nuclei and then 3 helium nuclei fuse ...
2
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2answers
363 views

Do other planets affect the Earth?

Let say Mercury, Venus, the Moon were all in alignment between the Earth and Sun. They are all closest to each other in respective elliptical orbit. On the other side of the Sun you have the rest of ...
5
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3answers
241 views

Can I slice off a piece of the Sun?

Bear with me. I want to explain this to my 6 and half year old. If, all things being equal, we could reach out to the Sun with a suitable implement, a gigantic space knife, could we cut a piece off ...
1
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1answer
86 views

What are the lines in this Solar Cycle graph?

What do the lines in this NASA graphic represent? Why does Solar cycle 22 have a peak of nearly 300 (assuming that peak represents the maximum observations at the same time) and this link says the ...
3
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5answers
537 views

Why is sun's photosphere a million times less dense than air at the surface of the Earth?

Sun's photosphere is about 19 times as hot as Earth's surface. (Source: http://solar-center.stanford.edu/vitalstats.html) But Solar surface gravity is about 28 times terrestrial surface gravity. So,...
1
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1answer
322 views

Path of sun calculation using java

if I am not using very odd programming language for Astrophysicists, here is my code for calculating path of sun. I am following this reference I want to calculate the local time as a function of ...
4
votes
1answer
657 views

How would latitude affect day/night lengths on a planet with no axial tilt?

How would the length of day and night change with changes in latitude on a planet with no axial tilt? Would the poles of the planet be in constant sunlight?
4
votes
1answer
215 views

How do sunspots move seen from the side?

Sunspots rise vertically? Do they float on the surface like oil? Do they flow up or down vertically from the Sun's core like a lava lamp?
8
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1answer
4k views

Why do stars twinkle but the Sun doesn't (I'm asking this because the Sun is also a star) [duplicate]

My friend asked me "Sun is also a star then why doesn't it twinkle like other stars" I brought this question here so that I have (and have more) infomation on this topic.
3
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1answer
222 views

Jupiter vs brown dwarf star

What would happen to Jupiter if a brown dwarf star collided with it, and vice versa what would happen to the brown dwarf star?
2
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1answer
157 views

What is the inclination of Mercury's orbit w.r.t. the Sun's equatorial plane?

What is the inclination of Mercury's orbit w.r.t. the Sun's equatorial plane? Additionally, what is the orientation of Mercury's orbit (long axis) w.r.t. the Milky Way?
7
votes
1answer
255 views

Temperature of Earth if tidal locked with the Sun?

Assume the Earth somehow stopped spinning once every ~24 hours, and instead started rotating at ~365 days per rotation, so it effectively would end up being tidal locked with the Sun. In this ...
2
votes
0answers
36 views

Aaditya L1 mission ISRO

ISRO's next mission to the Sun is Aditya-L1, (also here), which will be placed at the Sun-Earth Lagrangian point L-1. Why it is not placed near L-4 or L-5, since these are stable equilibrium point ...
9
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2answers
526 views

What star is directly north of the suns north pole?

If Polaris is Earth's North Star as it is directly pointed at by our North pole, what would be the North Star of the Sun?
4
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1answer
277 views

Sun Zenith angle and location on earth

Let suppose you are at +3 degrees latitude (3 degrees north of Equator ... for example at Cali in Colombia). At what periods of the year will the sun be at your vertical (at your zenith) at noon? I ...
3
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1answer
381 views

How do I adjust the sunrise equation to account for elevation?

I have been working with the sunrise and sunset formula, using the equations from Wikipedia. The problem is that, in my usage thereof, it seems that it only works for sea level; if I start with ...
3
votes
2answers
1k views

How to calculate the maximum and minimum solar azimuth at a given location?

Every Azimuth equation I have been able to locate so far depends on inputting a time, and I do not want to have to brute force the solution by simply trying all of the times. (See below for standard ...