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Questions tagged [keplers-laws]

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3 votes
1 answer
84 views

Orbit equation solver giving wrong orbits

Recently I've become interested in simulating orbital mechanics using Kepler's equations, and in Unity I created my own equation solver by following this paper I found. However, inputting Earth's ...
2 votes
0 answers
59 views

T Coronae Borealis

As it will explode this year or so, I became interested in the binary T Coronae Borealis. According to wikipedia, https://en.wikipedia.org/wiki/T_Coronae_Borealis R Cor Bor the binary masses are 1.34 ...
4 votes
3 answers
226 views

Keplers laws and this question

A planet (mass m) is orbiting a star (mass M) at a distance a. The distance of the star from the centre of gravity of the system is a' . Show that $$ MP^2 = a^2(a-a') $$ So first we can assume that $M ...
4 votes
2 answers
1k views

What's the simplest evidence for Kepler's first law?

What is the simplest explanation that provides enough evidence for the first Kepler law? i.e. that planets around the Sun travel on ellipses with the Sun at one of the two foci. Are the three Kepler ...
2 votes
1 answer
41 views

How can I determine a planet's orbital size if it is moving around an oscillating star?

I'd like to know how to calculate the size of the planet's orbit, given that it is the only one orbiting around a star, and that this star is oscillating with an amplitud of 0.026'' in 25 year periods....
4 votes
2 answers
1k views

Calculating the separation of binary stars

I'm struggling with the following problem: An eclipsing binary has period 0.10 years and each component has speed in its orbit of 19AU per year (or 90km/s) Assuming both stars have the same mass and ...
1 vote
1 answer
104 views

Mass of secondary normalized to 1 au

What does Mass of secondary normalized to 1 au in this catalogue https://vizier.cfa.harvard.edu/viz-bin/VizieR?-source=J/A+A/623/A72 mean, please? I tried to multiply that by Jupyter mass and the ...
4 votes
1 answer
743 views

What is a Keplerian frequency, why do we specifically say Keplerian?

I am assuming that it means the frequency of a planet on its orbit. But why do we specifically say Keplerian? Is there some other kind of definition of frequency we use for astronomical bodies in ...
2 votes
2 answers
202 views

At what distance does MOND Modified Newtonian Dynamics take effect?

At what distance does MOND Modified Newtonian Dynamics take effect? I understand MOND is described in relation to very slow accelerations, which is related to distance. It is mentioned it has an ...
2 votes
1 answer
413 views

Calculate eccentric anomaly using Kepler's equation

I'm developing a C++ computer library with the formulas in the book "Practical Astronomy with your Calculator or Spreadsheet 4th Edition" but I have a problem with the formula 56, "...
4 votes
1 answer
245 views

Scaling Relations

In this picture , Keplers third law is written in a scaling relationship with solar mass. $$a^3=\frac{G(m_1+m_2)}{4\pi^2}P^2 \rightarrow m_1+m_2 = \frac{4\pi^2a^3}{GP^2}$$ $$m_1+m_2=(1 M_{\odot})\, \...
2 votes
1 answer
136 views

Why is there a deviation between the ratio of $a^3$ and $T^2$ for the outer planets?

The Wikipedia article about Kepler's third law includes a nice table about the ratio between $a^3$ and $T^2$. However, for Mars, Jupiter, Saturn, Uranus, and Neptune, the ratio $\frac{a^3}{T^2}$ in $...