Questions tagged [keplers-laws]

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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 ...
Moiz khokhar's user avatar
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2 answers

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 ...
Jen's user avatar
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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....
Golan's user avatar
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4 votes
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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 ...
Ray61's user avatar
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1 vote
1 answer

Mass of secondary normalized to 1 au

What does Mass of secondary normalized to 1 au in this catalogue mean, please? I tried to multiply that by Jupyter mass and the ...
Anna-Kat's user avatar
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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 ...
WDUK's user avatar
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2 answers

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 ...
Brooks Nelson's user avatar
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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, "...
VansFannel's user avatar
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1 answer

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})\, \...
Particle king's user avatar
2 votes
1 answer

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 $...
WarpPrime's user avatar
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