All Questions
Tagged with orbital-motion astrophysics
86
questions
0
votes
1
answer
44
views
The magnetic force between the earth and the sun
There is a magnetic field around the earth and a stronger one around the sun. I guess there should be a magnetic force between the sun and earth. Now, shouldn't we take the magnetic force into account ...
- 11
1
vote
0
answers
12
views
How close does a dwarf star have to be to remove the corona from its neighbour in an elliptic binary system?
It is possible for a larger (wider, but less massive) star to mutually orbit a heavy dwarf companion star in a binary system. If the dwarf star gets close enough it can attract the corona of the ...
- 5,148
1
vote
2
answers
68
views
Is Each Day the Same Duration?
Since Earth's orbit is elliptical surely each day does not have the same duration. My understanding is that at the perigee the Earth would have to rotate more than at the apogee due to its larger ...
- 25
1
vote
1
answer
74
views
Tidal effects of galaxies orbiting one another in presence of dark energy?
I recently asked this question about whether there was a "distance" between two galaxies where both the gravitational force and the influence of dark energy would be balanced. The answers ...
- 2,462
1
vote
1
answer
50
views
Would there be any way to avoid gravitational waves emission in some orbital configurations?
In principle every object orbiting another (e.g. a planet revolving around a star) would emit gravitational waves, relaxing the orbit over time.
However, this would not happen if the orbits had a ...
- 2,462
3
votes
1
answer
94
views
In a binary black hole system, can one of the black holes get ejected before merging in some contexts?
As it is said here (https://physicsworld.com/a/couple-emerges-from-trio-of-supermassive-black-holes/) a system of two orbiting black holes could disrupt the gas and stars at the center of the galaxy ...
- 2,462
0
votes
1
answer
37
views
Do only gas planets have discs or even rocky planets may have them orbiting around?
Do only gas planets have discs or even rocky planets may have them orbiting around? If rocky planets are great in volume is then a higher chance for an orbiting disc to exist in the planetary orbit?
- 2,255
-2
votes
2
answers
51
views
Sling-Shooting Around a Star to Catch a Solar Flare
How much thrust could a solar sail receive from sling shooting around the Sun and riding the wave of a solar flare during the escape?
I found this link https://ww4.fmovies.co/film/the-ark-season-1-...
user265090
1
vote
0
answers
57
views
Is sun orbiting the center of the Milky Way? [closed]
Are all the celestial bodies in our galaxy (along with the Sun) orbiting the center of the Milky Way Galaxy?
- 11
0
votes
3
answers
366
views
Are moons always smaller than the planets they orbit?
I'm not a physicist, asking for knowledge. Is there any moon orbiting a planet, but bigger than that planet? If not, is it mathematically possible for a bigger object to orbit around a smaller object ...
- 113
0
votes
1
answer
115
views
Orbit of a planet around a black hole
If we observe from Earth a planet in very close orbit around a supermassive black hole (as close as possible to the black hole without the planet being swallowed up or destroyed by tidal forces), ...
0
votes
1
answer
123
views
What's the derivation of an orbiting object's energy in Kerr Spacetime
If in Schwarzschild spacetime, the energy per unit mass ε of an object is given by the following equation in timelike geodesics (derived from the squared magnitude of timelike tangent vectors at θ=π/2)...
- 103
0
votes
1
answer
95
views
Does the RA and DEC of the sun change with time?
I'm almost certainly misreading this, but it's said that "one of the great advantages of the equatorial system is that the RA and Dec of a star do not change with time, at least over short ...
user332426
-3
votes
1
answer
201
views
If barycenter true, then how general relativity explain it?
I found that earth actually doesn't orbit sun. Sun and other planets both orbit the barycenter(Their central of mass).Then, what about Einstein's theory ? That heavy mass(sun) wrap space-time, thus ...
- 7
2
votes
1
answer
392
views
How many full orbits around the galactic center our Earth has done so far since its creation?
I have read that the estimated age of our Milky Way galaxy is 13.61 billion years which is by using our current size and status of our galaxy about 59.17 Galactic years which each galactic year ...
- 4,170