Questions tagged [eccentricity]
The eccentricity tag has no usage guidance.
9
questions
10
votes
2answers
1k views
What is the difference between the two terms named “Eccentricity” and “Ellipticity”?
I don't get the difference between the two terms named "Eccentricity" and "Ellipticity", especially, in astronomy. I understand eccentricity as a measure of the curvature of a ...
2
votes
0answers
21 views
Relation between inner and outer eccentricities in a hierarchical triple star system
According to Table 3 of Sterzik & Tokovinin (2002), the inner eccentricity of a triple star system (i.e. the eccentricity of the inner binary) is, most of the times (70%), larger than the outer ...
6
votes
1answer
318 views
Cannot identify mistake in calculating orbital eccentricity vector; magnitude equals one instead of zero (with python code)
I have a gravitational nbody simulation, for which I would like to determine various orbital parameters. For each body, I have 3-D vectors (x,y,z -space) for position, velocity, and acceleration. I am ...
3
votes
0answers
52 views
Does gravitational radiation change the eccentricity of binary orbits?
Do the eccentricity of a binary orbit change with change in the semimajor axis due to loss of orbital angular momentum by gravitational radiation?
3
votes
1answer
79 views
What kind of effects can maintain Uranus' rings' eccentricities?
The recent paper Thermal Emission from the Uranian Ring System has been in the news recently. The introduction mentions:
The ε ring, the brightest and most massive of the narrow rings, was shown to ...
2
votes
1answer
262 views
How close to circular is the Earth's equator
Earth's orbit is about 99% circular. How circular is Earth around the equator? I know it bulges around the equator and is a spheroid. I also know it is not smooth and has oceans and mountains and all ...
1
vote
2answers
2k views
Calculation of Eccentricity of orbit from velocity and radius
For a school project I am making a gravitational computer model. As I want to Milankovitch cycles, I need to calculate the eccentricity of an orbit after the model has completed its simulation.
I ...
9
votes
1answer
328 views
Why has the orbit of Venus such a low eccentricity?
The eccentricity of Venus is almost 14 times smaller than that of Mars, and 2.5 times smaller than that of Earth, and 30 times smaller than that of Mercury. Is it just a pure fluke? Or is there some “...
1
vote
1answer
127 views
Eccentricity and Inclination of a Star
I understand Planetary Eccentricity and Inclination. However when it applies to a star, does the centre or ecliptic plane refer to the Sun or the Galactic Centre?
The star Sirius for example, 136....
