Questions tagged [the-sun]

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

Filter by
Sorted by
Tagged with
2
votes
1answer
64 views

Is the equinox absolutely true east everywhere?

I've read that only only in the equinoxes do you get to see the sun rise in the exact east regardless where you might happen to be. However I think this is not absolutely true everywhere, but only in ...
10
votes
1answer
1k views

Replenishing hydrogen in the core of the sun

How is hydrogen supplied to the core of the sun? Shouldn't the radiative zone prevent this? Shouldn't heavier helium fill the core? How much of the hydrogen can the sun fuse?
3
votes
2answers
1k views

Can you provide a visual description of the sun rise?

The Sun rises in the east only two times a year. The other days, the Sun rises in the east, but a little bit to the north, or to the south. How can you know the degree of how much north or south it is?...
3
votes
0answers
69 views

Information on Planetary nebula formed from the death of our star the 'Sun'!

I want to know the expansion rate, composition, mass and density of hydrogen present of a Planetary nebula similar to that which will be formed after the death of our star the sun. Knowing these ...
2
votes
1answer
48 views

How close would the sun have to get to a supermassive black hole to have Jupiter stripped and slingshot into interstellar space?

Please make whatever assumptions are needed. Assume sun approaches black hole on some sort of hyperbolic trajectory. Assume size of supermassive black hole is same as the one at center of our galaxy....
0
votes
0answers
21 views

Why were solar constant measurements before TSIS-1 all about 0.3% high?

Phys.org's Solar energy tracker powers down after 17 years says: "The big surprise with TSI was that the amount of irradiance it measured was 4.6 watts per square meter less than what was expected,"...
1
vote
0answers
64 views

What is the dielectric constant of a star?

1) What is the dielectric constant of a star, especially its corona? Is it of order 1 or is it quite large? 2) How much do "impurities" (elements other than H and He) affect the dielectric constant?
-1
votes
0answers
105 views

Earth circles Sun or opposite? [duplicate]

I've been talking with a friend about our galaxy and mentioned that our planet (earth) circles the sun. He said that it is not necessary to say so, and added that this claim is not stronger than the ...
61
votes
2answers
11k 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 ...
2
votes
0answers
65 views

Calculating the position angle of the moon (the rolling back and forth)

I have been watching the the NASA Moon Phases Video of the year 2020. Pretty much everything makes sense and I know how to calculate it including the moon phases, declination, azimuth, apogee and ...
7
votes
1answer
2k views

Our sun becoming a red giant

If our sun was already in the process of becoming a red giant, would the gradual rise in luminosity be noticeable to our eyes at some point in human existence?
3
votes
1answer
639 views

Why does the Sun move slower during the solstices?

A comment under this answer states that the apparent angular speed of the Sun is 8% slower during the solstices. This is rather counter-intuitive, since the rotation speed of the Earth is constant (or ...
1
vote
2answers
129 views

How does energy (from fusion reactions still inside the sun) still have gravitational attraction?

In this answer they say: While the conversion of mass matter† to energy in the Sun's core now represents a loss of mass proper matter, it turns out that that energy (trapped in the Sun and slowly ...
11
votes
1answer
363 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 ...
53
votes
2answers
10k 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?
0
votes
1answer
45 views

Earth-sun distance [duplicate]

I understand that the moon - Earth distance is increasing as the friction of tidal action causes energy loss. Does this mechanism happen with the Earth and other planets, is the Earth - Sun distance ...
1
vote
2answers
52 views

Is it possible to affect Earth's orbit so that, say, aphelion happens sooner?

As part of its natural cycle, the sun is currently drifting away from the Earth, it's predicted to reach its farthest point by July 4th in 2020, at which point the distance between the Sun and Earth ...
5
votes
1answer
137 views

Was the Earth-Sun distance ever calculated based on the time difference between night and day?

If we define sunrise and sunset as the time when the center of the Sun goes over the horizon then day time is a little bit shorter than night time because from a single point one cannot see a complete ...
3
votes
1answer
89 views

Are Sun-Earth L1 & L2 points generally considered outside the Earth's Hill Sphere?

This image from Wikipedia of the SE Lagrange points and the Hill Spheres suggests that the SEL points are outside the Earth's Hill Sphere. (The Hill spheres are the circular regions surrounding the ...
1
vote
1answer
75 views

Are there celestial bodies that are about as far away as the Sun?

Just curious. The Sun is 500 light seconds away from the Earth depending on time of the year. The orbit of Mars is about 50% as far as the Sun, the orbit of Vesta about 150%. Is there / Are there ...
0
votes
1answer
65 views

How is the Sun tilted to its orbit around the Milky Way's center?

We know how the Sun is tilted in reference to its planets but how is it tilted to Sagittarius A or its orbit around it? Or isn't it tilted at all?
4
votes
1answer
227 views

How much more life could the Sun acquire via star lifting?

It has been proposed before that we could use this technique to remove hydrogen from the Sun to lower it's rate of fusion and extend it's life, so it doesn't fry our planet. I am wondering how much ...
20
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 ...
0
votes
0answers
72 views

Could the Sun's planetary nebula be dangerous for the planets?

Since the Sun's mass isn't high enough it won't go supernova being a red giant but instead release a planetary nebula. So that seems to be kind of a substitute for a supernova. Would ejecting the ...
2
votes
0answers
39 views

How do I calculate moon phase orientation at any Coordinates given all the necessary data?

I'm having a problem for a couple of days where I'm trying to accurately calculate the phase angle of the moon at any given Coordinates (lon,lat).If I know my current Coordinates, Moon and sun ...
4
votes
0answers
48 views

What is happening with these solar particles detected near the Sun that is so newsworthy?

Phys.org's Team identifies low-energy solar particles from beyond Earth near the Sun links to the open access ApJ article Properties of Suprathermal-through-energetic He Ions Associated with Stream ...
5
votes
1answer
990 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 ...
6
votes
1answer
313 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 ...
30
votes
3answers
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 ...
18
votes
1answer
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 ...
22
votes
3answers
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 ...
4
votes
2answers
100 views

Moonrise after sunrise but moonset before sunset?

Today (1/24/2020) for Boston MA timeanddate.com lists the following four times: Sunrise 7:05 AM Moonrise 7:06 AM Moonset <...
2
votes
1answer
199 views

Why we can't see our Sun as it was a few years ago?

Our Sun is orbiting the center of the Milky Way galaxy. So many years ago, it was at a different location from where it is now. In addition, we are observing stars and exoplanets as they were many ...
2
votes
1answer
79 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. ...
0
votes
0answers
26 views

The sun networks [duplicate]

For my research about the sun activity I need to edit pictures of the sun. I want the pictures to show three stages the quiet, enhanced and active/plage network. I couldn't find any information in the ...
1
vote
1answer
30 views

Difference between quiet, enhanced and active networks

For my research about the sun activity I need to process pictures of the sun. I want the pictures to show 3 stages the quiet, enhanced and active network. I couldn't find any information in the ...
6
votes
1answer
95 views

Is there a verification of the solar system barycenter as it is theoretically determined?

The barycenter of our solar system is not the sun, but a changeable location outside of the center point of the sun. A often used diagram of that relation is shown below, originated from the Wikipedia ...
0
votes
0answers
17 views

X-rays, Solar wind and Sun's corona

I was reading that Solar corona emits the solar wind however also X-rays. What is the difference during the creation of these effects and impacts on our atmosphere? Thank you!
0
votes
0answers
37 views

Calculating angle between the sun and a perpendicular to earth given lon/lat & time

If you had your longitude/latitude, and the time/date, how could I go about working out the angle between your normal and the sun? At first I was doing a simplistic approach of assuming elliptical ...
0
votes
0answers
40 views

Astronomical events and Celebrations

In the past people celebrated important astronomical events and some of those events are still celebrated in some cultures and traditions. For example: March/September equinox, New Moon, Winter/...
0
votes
0answers
32 views

Stellar interior structures

im really confused on how i relate mass to radius of a star with a non constant density. more specifically i cannot seem to find an equation that states how density varies throughout a main sequence ...
2
votes
1answer
44 views

Does Earth's magnetic field become stronger when a solar flare hits?

This curiosity arises as follows: when ejecta from a strong solar flare hits Earth, will the Earth somehow counter its impact with a stronger magnetic field. Or, earth's magnetic field as limited ...
3
votes
0answers
38 views

Why do CME's “zig-zag” on their way to Earth?

This answer states: A single CME will impact a spacecraft from only one direction, but that direction might not be directly from the sun because a CME may zigzag en route. Looking at that link, ...
2
votes
1answer
91 views

Latitude of given altitude of Sun

From Question #6 of USAAAO First Round 2018 (1 point) For the following problem find the range in which the answer lies: on the day of summer solstice, on which geographic latitude is the sun ...
2
votes
1answer
147 views

Why do the magnetic field lines of the earth go from south pole to north pole?

I saw these figures and could not get why the magnetic field lines are not pointing from the north pole towards the south pole but they do the opposite. Or also this picture which is about magnetic ...
1
vote
1answer
92 views

Sun and moon's orbit in ecliptic coordinates using skyfield

I am new to using skyfield, is there any doc or help file that can show me on how to get the orbit of Sun and moon in ecliptic coordinate for a particular date and ...
0
votes
0answers
80 views

how is it possible to see the sun and the moon at the same time? [duplicate]

I once saw the sun and the moon at the same time once. How is this possible? Im from london england U.K and this probably some time in 2017 autumn time at around 6pm any Ideas.
2
votes
2answers
131 views

Is the sun flipped on the other side of the world?

As the orientation of the moon is different in the northern and the southern hemisphere, is the orientation of the sun different in both hemisphere? Does a sunspot appearing in the Sun northern ...
1
vote
2answers
68 views

Can I use the Tokyo Skytree as clock?

After my observation today at the Skytree in Tokyo, I am wondering if this building could be used as a giant sundial? As an aside, it would be interesting to consider how the Skytree might be used ...
44
votes
2answers
4k 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 ...

1
2 3 4 5
12