Questions tagged [the-sun]
Questions regarding the closest star to Earth, at the centre of the Solar System.
486 questions
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63 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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28 views
Field rotation / Parallactic angle question
edit: I am assisting a heliostat practical where students take spectra of a solar projection and calculate the rotational velocity of the Sun and the angle under which it is rotating. One of the ...
1
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1answer
62 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 ...
11
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1answer
1k views
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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0answers
51 views
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 ...
3
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0answers
45 views
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 ...
2
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1answer
79 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 ...
1
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1answer
45 views
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 ...
8
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2answers
136 views
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 ...
1
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0answers
38 views
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....
1
vote
2answers
56 views
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 ...
2
votes
2answers
54 views
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?
3
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1answer
47 views
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 ...
1
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0answers
43 views
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 ...
1
vote
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
28 views
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 ...
0
votes
2answers
68 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 ...
9
votes
1answer
936 views
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 ...
1
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0answers
37 views
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 ...
1
vote
2answers
59 views
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....
15
votes
3answers
2k views
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 ...
2
votes
1answer
60 views
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 ...
5
votes
2answers
143 views
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 ...
3
votes
2answers
84 views
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 ...
6
votes
1answer
82 views
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 ...
6
votes
1answer
80 views
22° Sun halo today in Zimbabwe. But there's a moon like thing inside the halo beneath the sun that cannot be seen with the naked eye, what is that? [closed]
Guys what is that moon like thing inside the halo?
3
votes
3answers
71 views
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 ...
4
votes
1answer
82 views
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 ...
6
votes
2answers
73 views
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 ...
3
votes
0answers
35 views
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 ...
4
votes
3answers
1k views
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?
0
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1answer
63 views
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 ...
8
votes
1answer
670 views
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 -- ...
0
votes
1answer
57 views
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 ...
0
votes
2answers
142 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 ...
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2answers
153 views
From what distance would our sun have an angular diameter of 7 arc seconds?
If an observer travels away from our sun, at what distance would our sun occupy 7 arc seconds of space?
2
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1answer
139 views
What is the orbital period of our sun around its barycenter?
In years, what is the time it takes our sun to orbit around our solar system's barycenter?
3
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1answer
69 views
What does it mean that the Sun`s rotation axis is: RA 286.13° , Dekl: 63.87°?
first post here.
I found 1 related Question, which has not solved my Problem.
SHORT QUESTIONs VERSION:
Suns axis is 7,25° tilted from the ecliptic. But in which direction?
LONG QUESTION:
Nasa ...
2
votes
1answer
106 views
What is the planet relative to earth that shows the greatest change in apparent brightness?
What is the planet relative to earth that shows the greatest change in apparent brightness?
I think the answer is Mars, and a quick google search reveals it is Mars.
I have my reasoning here, but I ...
2
votes
2answers
136 views
Calculate position of the Sun in ECEF
I'm making a very basic orbit simulator in C# using the Helix Toolkit.
I want to position the Helix lighting object at the sun, but also be able to calculate solar eclipse by the moon and earth for a ...
4
votes
0answers
62 views
“Pluto Time” for any solar system body
A while back NASA made a site called Pluto Time, where you can enter your address and find that "...moment near dawn and dusk each day, where the illumination on Earth matches that of high noon on ...
2
votes
1answer
86 views
How much more atmosphere is the sun passing through at sunset as opposed to at its peak in the sky?
I was looking at the sun during a sunset earlier today and wondered how much atmosphere you need to be able to look directly at the sun without damaging your eyes. The thought crossed my mind because ...
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3answers
64 views
Hypothetically, if our sun was yellow would we still see “white” colours?
Hypothetically,if our sun was yellow would we still be able to see white colour on objects like snow,cotton etc.? Would we have the phenomenon of rainbow?
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2answers
148 views
How do astronomers know when the Sun will die?
How it is possible for astronomers to find out when the end of the Sun's life will be?
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1answer
70 views
What phenomena was this video from SOHO actually showing?
My friend showed me a video of a CME that looked as if it was swirling into a gigantic circular "spaceship" or "UFO" and he explained it as "an alien ship potentially refueling". I did a bit of ...
3
votes
1answer
74 views
Why does the adiabatic exponent decrease at the ionization zones?
The context is the ionization zones in stellar atmospheres or interiors, the Sun, for instance.
The adiabatic exponent is the heat capacity ratio:
$$\gamma = \frac{c_P}{c_V} = \frac{C_P}{C_V}$$
And,...
3
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0answers
55 views
Erratic Sundial
My sundial shows real time until 11am when it will drop behind an hour until sunset. This is in keeping with daylight saving but why does it show real time before 11am? Am I missing something ...
1
vote
2answers
68 views
Movement of the Sun in space
Does the Sun undergo any cycles or revolutions approximately every 24,000 years or 8.6 million years? In Hinduism it is believed that the Sun revolves in an elliptical orbit around a large mass at ...
1
vote
0answers
32 views
What's the time in which the sun rises? [duplicate]
What's the time the sun takes in order to rise? (The time in which the solar disk crosses the horizon)
How does this time depend on local latitude and the sun's declination?
Assume that we're at sea ...
3
votes
0answers
73 views
+50
How much magnetic attraction is there between the Sun and Earth?
How much magnetism is there between the Earth and Sun? Would the distance from the Sun differ for not the Earth iron core and how much?
