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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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150 votes
2 answers
27k views

How much gold is there in our sun?

XKCD 1944 claims that there is "more gold in the sun than water in the oceans". Is this really true?
Jakub Šturc's user avatar
  • 1,379
141 votes
3 answers
23k views

How loud would the Sun be?

Sound can't travel through outer space. But if it could, how loud would the Sun be? Would the sound be dangerous to life on Earth, or would we barely hear it from this distance?
Jamie's user avatar
  • 1,179
108 votes
1 answer
22k views

How can there be 1,000 stellar ancestors before our Sun?

I've heard from a few sources* recently that the Sun is a 1,000th generation star, meaning it had a thousand stars that came before it based on its heavy-element content. I understand that earlier ...
Benjam's user avatar
  • 1,199
93 votes
6 answers
9k views

Does the Sun rotate?

The planets rotate as an after effect of their creation, the dust clouds that compressed span as they did so and the inertia has kept it rotating ever since. It's fairly easy to prove that planetary ...
user avatar
74 votes
2 answers
14k views

Is it dark inside the Sun?

This might sound like a strange question, but something got me thinking about it recently. The opacity of plasma in stellar interiors can get quite high, making for shorter free-paths for photons. In ...
Swike's user avatar
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60 votes
5 answers
13k views

When will the Sun end all human life on Earth?

If nothing else wipes out human existence prior to this, at what point will the Sun make Earth uninhabitable for humans?
Daniel Storm's user avatar
59 votes
2 answers
15k views

Would we have more than 8 minutes of light, if the Sun "went out"?

The common theory is, that if the Sun "shut down", we would see the light for eight more minutes (the time that it takes the photons to reach the Earth). However recently I have read that ...
Murg's user avatar
  • 939
57 votes
4 answers
17k views

How did Astronomers deduce that the Sun was not a ball of fire?

Its common knowledge that people used to think that the sun is a ball of fire or molten metal, but when did science start to prove otherwise?
Krish's user avatar
  • 703
56 votes
2 answers
11k views

Sun constantly converts mass into energy, will this cause its gravity to decrease?

If the sun is constantly converting the mass into energy, then will its gravitational field continue decreasing?
Mohan Mone's user avatar
54 votes
5 answers
20k 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 ...
Andrew Johnson's user avatar
50 votes
6 answers
8k views

Is the Solar core hard?

This may seem like a weird question, but something got me thinking about it just recently. The Sun's core is composed of mainly hydrogen and helium, and is present in the form of a extremely hot ...
Alastor's user avatar
  • 2,659
48 votes
5 answers
9k views

Where does the Solar System end?

The Sun is roughly 4 light-years away from the closest star system, the Alpha Centauri system. The planets in our Solar System, however, aren't even close to that far away from the Sun. Where does our ...
HDE 226868's user avatar
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46 votes
1 answer
6k 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 ...
Allure's user avatar
  • 4,544
46 votes
2 answers
6k views

Does the sun cross other spiral arms in its movement around the galaxy's center?

Today, Ansa.it released an article that states: [...]. In questo suo peregrinare galattico, il Sole ha attraversato anche i due bracci della Via Lattea Perseo e Centauro. "Sono zone di alta ...
Patrick Trentin's user avatar
40 votes
5 answers
6k views

Why can't we see Saturn's phases from earth?

In the Astronomy Picture of the Day from August 8, 2020 ("Crescent Saturn"), the caption states From Earth, Saturn never shows a crescent phase Why is this? We can observe phases on ...
jng224's user avatar
  • 979
37 votes
3 answers
10k views

What happens to the 99.9 % of the sun-rays that do not fall on any planets or any other celestial body?

I assume that about 99.9% of the sun-rays that do not fall on any planet or any other celestial body keep on traveling farther and farther unto infinity. Apparently such rays get lost. Keeping in mind ...
S C Sawhney's user avatar
36 votes
3 answers
7k views

Where did the Sun get hydrogen to work with if it is in the 3rd generation of stars?

As I see here, the Sun belongs to the Population I group of stars, which is the 3rd generation of the stars in our universe. 1st generation stars are Population III, 2nd generation are Population II, ...
Zlelik's user avatar
  • 615
35 votes
10 answers
14k views

Why doesn’t the Sun fill the sky on Mercury?

I’ve seen a lot of photos showing Mercury in front of the Sun when it passes by and you can see just how tiny it is in comparison. Here’s a great example: So I’d expect if I was travelling towards ...
Cameron's user avatar
  • 469
34 votes
4 answers
3k views

Is it odd that our Sun has so many planets?

The internet is abuzz with the new evidence of the possible ninth planet in our Solar System. With those nine objects, the asteroid belt, the Kuiper belt, and everything else in our Solar System - the ...
user10467's user avatar
  • 349
33 votes
6 answers
11k views

Why is the Sun's density less than the inner planets?

The density of the Sun is $1410~\frac{\text{kg}}{\text{m}^{3}}$ and Mercury's is $5430~\frac{\text{kg}}{\text{m}^{3}}$, but shouldn't the Sun be denser? Because when the Solar System was forming, ...
user11830's user avatar
  • 339
32 votes
3 answers
14k views

Can our Sun become a black hole

Does every star become a black hole? Is there any probability that our sun can become a black hole? If yes then is it on its way to become a black hole? what is the current state of sun as per the ...
Strikers's user avatar
  • 1,109
31 votes
3 answers
18k views

How far is the Earth/Sun above/below the galactic plane, and is it heading toward/away from it?

How far is the Earth/Sun above/below the galactic plane, and is it heading toward/away from it? We know the Sun is orbiting the galactic center every 225 million years. But how far are we from the ...
jmarina's user avatar
  • 1,016
29 votes
3 answers
5k views

What is this web on the surface of the Sun?

I was going through my Social Media Feed and found the attached post too frequent. The caption reads this is the best image of our Sun. Just as an example, the Universe Today's This is the Highest ...
Pranay's user avatar
  • 783
29 votes
2 answers
28k views

Why is it okay to watch a sunset but not an eclipse?

People watch sunsets all the time. You don't see people using special "sunset glasses". Yet with an eclipse, warnings are posted everywhere not to view it without special glasses. Why is this?
End Anti-Semitic Hate's user avatar
28 votes
4 answers
10k views

Why there is no smoke around the Sun?

Where there is fire, there is always smoke. So why there isn't any smoke near the Sun?
Pritam's user avatar
  • 461
27 votes
1 answer
5k views

Why is the summer solstice night shorter than the winter solstice day?

I was looking at the sunrise and sunset times where I live (Aberdeen, Scotland) and I noticed something odd: the time between sunrise and sunset in winter is longer than the time between sunset and ...
Nierninwa's user avatar
  • 373
27 votes
3 answers
7k views

Does the Sun have permanent geographical features?

Equivalent formulations of this question: Would it make any sense to draw a map of the Sun? Is the Sun heterogeneous with respect to latitude and longitude? (I know that it is heterogeneous with ...
Joshua Meyers's user avatar
27 votes
2 answers
24k views

Why do sunspots appear dark?

Sunspots, such as this one, appear dark: Why?
user avatar
26 votes
3 answers
5k 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 ...
xenfoulis's user avatar
  • 479
26 votes
3 answers
4k views

Why can't stars be multicolored like gas giants?

Gas giants like Jupiter and Saturn have bands of different colors in their atmosphere. These are due to the rotation of the planets. Stars rotate too, so why do most stars have patches/blotches of ...
harada's user avatar
  • 705
26 votes
2 answers
3k views

How often do stars pass within 1 light year of the Sun?

Interstellar exchange of massive objects is difficult across several light years. But as the stars orbit the galaxy the distances between them change. I don't find data for neighbor star distances ...
LocalFluff's user avatar
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26 votes
2 answers
3k views

Is it a coincidence that both the Sun and the Moon look of same size from the Earth?

The Sun is huge, when compared to the Moon. Despite the huge difference in their size and distance from Earth, is it purely coincidental that they both look almost the same from Earth?
Raj's user avatar
  • 371
25 votes
9 answers
17k views

Simple experimental evidence that Earth revolves around Sun

What are the simplest experiments or calculations that give evidence that the earth revolves around the sun? Can you please explain them and reference the history? Many simple explanations such as ...
user7496's user avatar
  • 351
25 votes
4 answers
3k views

How else can a star form, other than gravitational collapse?

I read this paragraph on the Sun's page on Wikipedia: [The Sun] formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most ...
John's user avatar
  • 251
24 votes
2 answers
4k views

At what distance from Earth would our Sun be the same apparent magnitude as the next brightest star in the sky?

When I stand outside looking at the night sky, to my untrained eye, everything except the moon looks like a star. I know intellectually that some are planets circling our sun, and some are entire ...
James Jenkins's user avatar
24 votes
3 answers
3k views

Did the Sun's light always peak in the green wavelengths?

So, I know the sun is getting brighter over it's lifespan and I'm wondering how that affects its emission spectrum. The reason I'm asking this is because I find it weird that plants reflect green ...
Elhammo's user avatar
  • 1,107
23 votes
2 answers
13k 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?
Max's user avatar
  • 417
23 votes
1 answer
1k views

Why is the Sun's atmosphere (the corona) so hot?

The visible surface of the Sun is 6000 degrees Celsius but the gas in the solar corona is at least 1 million degrees. What heats the solar corona?
ehsteve's user avatar
  • 1,164
22 votes
4 answers
9k views

Would an object shot from earth fall into the sun?

Would an object shot from earth fall into the sun? If an object is shot at 107,000 km/h via rocket or otherwise, in the opposite direction to our orbit about the sun, it will be traveling at 0 km/h ...
Taku's user avatar
  • 331
22 votes
2 answers
5k views

Do we know a star that is similar to the Sun when it would be a red giant?

In about 5 billion years the Sun is predicted to become a red giant and have more than 200 times its current size, reaching a radius of about 5 AU when largest. I wonder what spectral class the Sun ...
user30007's user avatar
  • 1,226
22 votes
4 answers
5k views

Does anything orbit the Sun faster than Mercury?

Mercury's orbital period around the Sun is about 88 days. Comets and other things have gotten closer to the Sun than Mercury does. But has there ever been an asteroid or some other body discovered ...
Connor Garcia's user avatar
  • 16.3k
22 votes
3 answers
5k views

When was it worked out/discovered that our Sun can't go supernova?

As the title says, when did we realise with reasonable confidence that our star is not going to be going out in a supernova blaze of glory? I ask because a while ago I read "The Songs of Distant ...
Wiggo the Wookie's user avatar
22 votes
1 answer
3k views

What's the brightness of Alpha Centauri from Proxima Centauri?

Self-explanatory, but I would like a comparison as well. Is the light enough to see by? How disrupted will the pitch darkness on the spot opposite of the 'solar pole' be?
GoingFTL's user avatar
  • 586
21 votes
5 answers
36k views

Does the Sun belong to a constellation?

Each new star we find is generally considered to be part of the constellation it is nearest to. Our Sun is obviously a star, just much closer. Is our Sun part of any constellation? If so, which ...
user avatar
21 votes
2 answers
3k views

How bright would the sun appear from the hypothetical Planet Nine proposed by Caltech?

Theoretical Planet Nine, proposed by Caltech's Mike Brown and Konstantin Batygin, is said to have a 15-20 thousand year orbit. Approximately how bright would the sun appear from Planet Nine aphelion ...
joseph.hainline's user avatar
21 votes
2 answers
3k views

How hard is it to find the Sun's "sisters?"

As @ProfRob stated in his excellent answer regarding the ejection of the Solar System's fifth gas giant, It is for similar reasons that, even though the Sun was probably born in a cluster of $\sim 10^...
WarpPrime's user avatar
  • 6,673
21 votes
2 answers
2k views

Was the Sun's gravitational lensing observed in other solar eclipses than the one in 1919?

In 1919 the gravitational lensing by the Sun has been observed during a total solar eclipse. Did someone observe the lensing in any other total eclipses? Last year there was a total eclipse in Chile ...
user30007's user avatar
  • 1,226
20 votes
2 answers
5k views

Is there enough matter orbiting the sun to make a second sun?

I read somewhere a long time ago that there is enough matter in our solar system in the form of rocks and dust to create another sun.Is this correct? Was our solar system trying to create a 2 star ...
user avatar
20 votes
5 answers
13k views

Was the Geocentric Model correct at all?

It's easy to find resources stating that the heliocentric model is right and geocentric is wrong. But how wrong was it? Was it correct in any way? It was built on incorrect assumptions, but despite ...
Voy's user avatar
  • 311
20 votes
3 answers
4k views

Is the power output at the core of the sun about the same as a compost pile (about 300 watts)?

I read an article at abc.net.au saying that the power output of the sun is about 276.5 watts per cubic metre, similar to that of a compost pile. A compost pile is not incandescent, while the sun is. ...
Sedumjoy's user avatar
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