All Questions
Tagged with orbital-motion binary-stars
44
questions
2
votes
1
answer
50
views
How to relate a gravitational plane wave to the GW from a binary system?
I have two different forms of gravitational waves that I am trying to reconcile.
A monochromatic GW with angular frequency $\Omega$ propagating in the $\textbf{n}$-direction can be expressed as
$$ ...
- 1,751
1
vote
0
answers
16
views
Where can I find spectra data and light curves of a stereoscopic binary star system?
I am trying to find a suitable source of spectra data and/or a light curve of a binary star (no exact star in particular), with which I would use to find velocity and period, and then find masses etc.....
- 41
0
votes
0
answers
68
views
Impact Parameter as function of orbital parameters
In the case of a binary system (pulsar+companion), the impact parameter $\textbf{b}$ is the projection of the binary separation $\textbf{r}$ on the sky plane:
\begin{equation}\tag{1}
\textbf{b} = \...
- 169
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
4
votes
0
answers
161
views
Confusion about Post-Newtonian orbital motion (Damour-Deruelle)
In their famous paper in 1985 (link), Damour&Deruelle describe the orbital motion for a binary system taking into account first-order post-Newtonian corrections (1PN). The solution is given in ...
- 169
0
votes
1
answer
32
views
Inquiry Regarding Hypothetical Celestial Mechanics Scenario
How would the addition of a second sun, located at the other focus of the planet's elliptical orbit, impact the motion and orbit of the planet? Specifically, how would the gravitational forces from ...
user379270
1
vote
0
answers
62
views
Stress-Energy Tensor for a Two Mass System
I just don't understand this tensor and would like to go through an example with you to somehow make sense of it.
I consider two spheres with masses $m_1$ and $m_2$, densities $\rho_1$ and $\rho_2$ ...
0
votes
1
answer
70
views
Can we correctly invoke energy conservation to explain why binary systems do collapse in GR?
I've learned that binary systems emits gravitational waves, so there is energy leaving the system in the form of waves and so the radius of the binary system must decrease as to maintain the ...
- 159
2
votes
0
answers
48
views
Orbital phase and gravitational wave phase
I am trying to understand the relation between the orbital phase of binary and the phase of the gravitational wave when expressed as spin-weighted spherical harmonics.
The metric perturbation can be ...
- 1,124
0
votes
1
answer
502
views
Methods for calculating the orbital speed of a star in a binary system
As I understand it, to calculate the speed of rotation of a star in a binary system that is receeding, that is in the same plane as us (inclined at 0 degrees) the method is use the Doppler formula: Δλ/...
- 103
1
vote
1
answer
62
views
Problem in an ellipse circumscribed on an auxiliary circle
I was reading the book "an introduction to the evolution of single and binary stars", by Mattew Benacquista, and I couldn't understand a specific step in topic 2.1 (Time-Depedent Orbits), ...
1
vote
1
answer
46
views
Closest possible orbital radius for equal masses
If you have two objects of equal mass, then what’s the closest distance that they can orbit at in terms of their schwarzschild radii? How fast would they be orbiting?
What About stable orbits?
- 2,908
0
votes
1
answer
119
views
Does the Centre of Mass of a binary star system accelerate?
At the COM of a binary star system (where both stars has a different mass), the net force at the centre of mass is non-zero.
Does this mean that the COM will be accelerating? And if so, wouldn't the ...
- 568
0
votes
1
answer
52
views
Can orbiting point masses precess?
In a recent Science News, it mentioned two orbiting black holes (which later combined) were precessing; i.e. their motion did not remain in a stable plane, but rather the plane itself was changing. ...
- 265
1
vote
1
answer
49
views
Pair of binary stars orbiting each other
Suppose we have a pair of binary stars orbiting around each other in their mutual gravitational field. My question is, is the trajectory of the combined system would be an ellipse?
And, if it is an ...
