Questions tagged [the-sun]

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

Filter by
Sorted by
Tagged with
3
votes
2answers
208 views

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.
2
votes
3answers
675 views

Brown Dwarf transcending past the sun with the naked eye [closed]

I seen with my naked eye in mid 2014 from Ca. right after sunrise a black spot in front of the Sun.I observed it for about a hour with my naked eye. Here is a picture that closely resembles what I ...
1
vote
1answer
134 views

What is the exact time of sun stay in each zodiac every year on sidereal year duration?

I tried to reverse engineer from astro-chart times at which sun stays in a zodiac. Here is the list. ...
-1
votes
2answers
179 views

Does the sun itself present the problem of global warming is it the main cause? [closed]

the sun itself is not responsible for global warming, it must be that the temperature is changing due to climate changes. Anyone?
-1
votes
2answers
2k views

Does the Sun move? [duplicate]

I'm curious; does the Sun actually move? The concept behind the question is that if you wear a shirt and you move, does the shirt actually move? The Solar System orbits around the Milky Way, but does ...
122
votes
3answers
18k 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?
86
votes
6answers
7k 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 ...
49
votes
4answers
14k 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?
22
votes
1answer
594 views

How stable are Lissajous orbits?

Now that the Gaia Space Telescope is on it's way to the Sun-Earth L2 Lagrangian point (SEL2), I start wondering about the stability of Gaia's orbit there. The Planck Telescope is already there, as was ...
19
votes
1answer
12k views

How many sun-like stars are there in the universe?

After yesterday's announcement of the Kepler telescope finding a huge amount of newly observed exoplanets, i saw a headline claiming that as much as 22% of sun like stars in the universe have planets ...
31
votes
6answers
10k 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, ...
19
votes
1answer
8k views

Why isn't the asteroid belt affected by Jupiter's gravitational field?

Jupiter's mass is just about a 1000th of the sun's and the asteroid belt is slightly closer to Jupiter than it is to the sun. If the heavier the object, the more curvy space is around it, why isn't ...
17
votes
6answers
8k views

Why do stars become red giants?

Disclaimer: I’m not a career astronomer. I don’t own a telescope. I have no professional credentials. But I do find this stuff fascinating, and I consume all the astronomy documentaries I can. ...
20
votes
2answers
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 ...
16
votes
1answer
409 views

How do large solar flares compare to flares on other stars?

Solar are violent releases of solar magnetic energy. Other stars are also known to have magnetic fields, in some cases much stronger than the Sun. How do the largest stellar flares compare to the ...
14
votes
3answers
4k views

Is the Jupiter-Sun system considered a binary system of some type?

Since Jupiter is very massive, it is the only planet (in our solar system) that has a center of mass with the Sun that lies outside the volume of the Sun. (Source) If Jupiter was a star, they would ...
9
votes
1answer
2k views

Solar Noon: meridian crossing time versus time of maximum elevation

According to the first paragraph of the Noon Wikipedia page, solar noon is the moment when the Sun crosses the meridian and is at its highest elevation in the sky. The wording there suggests that ...
4
votes
1answer
1k views

What's the rationale behind the false colours in solar observation photographs?

Images from SOHO, SDO and other sun observatories are often coloured differently for different wavelengths or temperatures: http://www.nasa.gov/mission_pages/sunearth/science/Sun-Wavelength-Chart....
28
votes
3answers
6k 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, ...
26
votes
3answers
2k 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 ...
19
votes
2answers
3k views

Do other planets in our solar system experience eclipses or is this unique to Earth?

Here on Earth we get to experience lunar and solar eclipses. Is this pure coincidence that everything happens to line up? Do other planets in the solar system experience this phenomenon or is this ...
15
votes
1answer
401 views

What are some theories that explain the 11 year solar cycle?

The Sun exhibits a periodic cycle for solar activity as manifested by solar activity (e.g. sunspots, solar flares). This activity is related to magnetic fields which emerge from the interior of the ...
12
votes
3answers
7k views

Why is twilight longer in summer than winter and shortest at the equinox

I recently decided to set my alarm clock to wake me up when it is "dark" out. In the end, I decided to set my clock to the earliest time that nautical sunrise is in my state (Illinois) and stick with ...
11
votes
1answer
418 views

How much mass does the Sun lose as light, neutrinos, and solar wind?

In this answer I estimate the loss of gravitational mass of the Sun to be about 1.3E+17 kilograms per year using $E = m c^2$ and 1360 W/m^2 at 1 AU. While writing that answer I realized that solar ...
8
votes
2answers
415 views

What does this “web on the surface of the Sun” image reflect? What does 789 nm show us?

What is this web on the surface of the Sun? has got me thinking. This is probably not a normal color photo. The cooler areas are really dark! update: Comments point out The NSO press release says ...
7
votes
1answer
294 views

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 ...
5
votes
3answers
219 views

Pinhole Projector: Can I use a specific solar optical eye piece to focus the Transit of Mercury?

The title pretty much explains this one. Can I use a specific solar optical eye piece, or other optical device, in conjunction with the pinhole projector method to focus the Transit of Mercury? ...
5
votes
1answer
1k views

What does the Sun look like from Eris at its aphelion?

At its aphelion (most distant location from the Sun) the outermost-known planet Eris is about 100 times as far from the Sun as Earth. What does the Sun look like from Eris' surface? Is there still a ...
4
votes
2answers
382 views

Are there good animations of the movement of proximate stars over long time periods?

After reading about Barnard's Star and how it's approaching us 140 km/sec, I'm curious if there are any visualizations of how the nearest stars to Sol will be moving over the next 100k years or so. ...
4
votes
1answer
280 views

Finding Latitude and Longitude of a person or of where a picture was taken

this is my first post on the Astronomy stack exchange site. Please let me know how this question is based on y'all's generally accepted criteria for a good question as well as possible improvements. ...
4
votes
2answers
482 views

Sun's orbital elements

I have the orbital elements of an asteroid's heliocentric motion (the orbit has non-zero inclination and is elliptical). But I want to simulate the motion of the sun around the asteroid. So without ...
3
votes
1answer
142 views

Source of high energy cosmic particles

Earth receives shower of both solar and cosmic radiations every seconds. The Sun put up a heliosphere around the solar system and thus foreign high energy charged particles could not penetrate easily. ...
3
votes
2answers
3k views

Revolution of the sun

It is believed that there is a black hole at the centre of the Milky Way galaxy. And the sun revolves around the centre of the milky way. So does it mean our sun is revolving around the centre of the ...
3
votes
1answer
220 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,...
22
votes
3answers
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 Earth ...
20
votes
3answers
4k 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 ...
19
votes
4answers
4k views

Did the earth form outside the solar system?

Why isn't it possible that the earth formed outside the solar system and got attracted later by the Sun? I just need arguments to defeat this hypothesis.
15
votes
1answer
973 views

What would the Sun be like if nuclear reactions could not proceed via quantum tunneling?

Without quantum tunneling our Sun wouldn't be hot or massive enough to produce the energy it does at the moment. So what would have been the temperature or mass of our Sun without quantum tunneling of ...
12
votes
4answers
839 views

Using the Sun as a Gravitational Lens

Can the Sun be used as a gravitational lens to achieve better telescopic viewing? Can this effect be practically used to view celestial objects?
12
votes
5answers
894 views

How do you define the diameter of the Sun

That is, it's twice the radius where the radius is from the centre of the sun to some edge. But what is that edge?
12
votes
1answer
252 views

How can only 1 magnetic pole of the Sun change at a time?

I read some news stories about the current Solar maximum and the flipping of the magnetic poles. They say that one of the magnetic poles has switched polarity and the other will switch in about a ...
12
votes
3answers
4k views

Will just a glimpse (less than a second) of sun during partial solar eclipse damage eyes?

This doubt arised when I thought that on normal days, at least I have observed bright sun while going outside, going to office, in park etc. for less than a second. It happens almost daily. Not ...
10
votes
3answers
913 views

Should this photo of the sun's surface actually be white?

If I'm told correctly (eg. What Color is the Sun?) that the sun is actually white, should the photo on that page actually be white too? Is it just doctored to meet peoples expectations?: Likewise for ...
9
votes
1answer
868 views

Why does the Sun deviate from a typical blackbody spectrum in the S band?

This is sort of a follow-up to this question, and my answer to it. The graph I see here details the radio (and other frequencies) emission of the sun. What's most notable and interesting to me is the ...
8
votes
1answer
116 views

Is the gravitational field of the sun uniform?

I understand that rocky bodies in the solar system all exhibit gravitational anomalies. Does the sun exhibit any gravitational anomalies? If so are they distinct enough that it effects the orbit of ...
8
votes
2answers
659 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 ...
7
votes
3answers
1k views

Can the Sun become a big ball of gold atoms?

The atoms inside the core of sun are continuously fusing and forming other atoms. Can this continuous fusing make gold atoms?
7
votes
1answer
294 views

At what distance would it be safe for humans to stare at the sun?

Let's say we could travel anywhere in the solar system, at what distance would it be safe for a human to stare at the sun (without eye protection) and not get eye/retina damage? (Not sure where this ...
7
votes
1answer
613 views

Does Eddington's variable polytropic index better fit data from the Standard Solar Model?

I came across a 1938 paper by Arthur Eddington1 in which he discusses stellar polytropic models where the polytropic index $n$ varies inside the star, decreasing from a value $n_2$ at the surface to a ...
7
votes
1answer
165 views

Are sunspots vertically displaced from the surrounding photospheric plasma?

While reading a paper on the helioseismology of sunspots (Cameron, et al.), very brief reference is made to the "vertical displacement of a blob of plasma." This caused me to wonder if the emissive ...