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TFM
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[SOLVED] Extra-Solar Planets and their stars wobble
An extra-solar planet is detected by observing that its parent star had a radial velocity 'wobble' of amplitude 40 m/s. If the parent star has a mass of one Solar Mass, and the period of the 'wobble' is four days, find a lower limit for the mass of the planet in solar masses.
[tex] F = \frac{GMm}{r^2} [/tex]
Kepler [tex] T^2 \propto R^3 [/tex]
I have calculated the radius of the planet using Keplers third law, assuming that the wobble's period will be the same as the planets period, since thewobble is due to the star/planet system orbiting a common centre of mass, but I am not sure how to fine the Mass, I think I need Netwtons Gravitational law, as stated above, but I am not sure how to find the gravitational force, F, exerted?
Any ideas?
TFM
Homework Statement
An extra-solar planet is detected by observing that its parent star had a radial velocity 'wobble' of amplitude 40 m/s. If the parent star has a mass of one Solar Mass, and the period of the 'wobble' is four days, find a lower limit for the mass of the planet in solar masses.
Homework Equations
[tex] F = \frac{GMm}{r^2} [/tex]
Kepler [tex] T^2 \propto R^3 [/tex]
The Attempt at a Solution
I have calculated the radius of the planet using Keplers third law, assuming that the wobble's period will be the same as the planets period, since thewobble is due to the star/planet system orbiting a common centre of mass, but I am not sure how to fine the Mass, I think I need Netwtons Gravitational law, as stated above, but I am not sure how to find the gravitational force, F, exerted?
Any ideas?
TFM