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Can a planet move around a star in an exact circle? Does Kepler's laws prevent this from happening. Answers with mathematical base will be accepted.

N.S.JOHN
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    There are no "exact" circles in nature. Can an orbit be essentially circular? Yes. – CuriousOne Jan 23 '16 at 03:49
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    @CuriousOne In classical mechanics there are exact circles, just like there are exact ellipse, taking a circle being as an infinite sided regular polygon. Why isn't any of the planet's in our SS not having circular paths? What are the requirements for a circular path? Can you put it mathematically into an answer? – N.S.JOHN Jan 23 '16 at 03:55
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    Refer. http://physics.stackexchange.com/questions/69997/why-dont-planets-have-circular-orbits?rq=1 – Anubhav Goel Jan 23 '16 at 03:58
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    Classical mechanics is an approximate mathematical description of nature, it's not nature. You were asking if planets can move around stars in exact circles and the answer to that is no, real planets moving around real stars can't do that. There are always other masses that tug on their orbits and circular orbits are singular elements out of a continuously parametrized set of orbits, so hitting just the right combination of orbital energy and angular momentum is practically not possible. I know that is not what you are asking, but we have enough confusion between theory and reality, already. – CuriousOne Jan 23 '16 at 04:00
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    Even in classical mechanics there are only exact circles in the strict two-body case. The universe has more objects than that. Draw your own conclusions. – dmckee --- ex-moderator kitten Jan 23 '16 at 04:07
  • Note that Kepler said planets follow elliptical orbits, and a circle is an special case of an ellipse. So in an ideal case with only two objects yes it could happen but in nature it doesn't. – Suriya Jan 23 '16 at 10:17
  • @Pablo Yes, and the answer I got is yes. – N.S.JOHN Jan 23 '16 at 10:18
  • @N.S.JOHN what do you mean, what answer? – Suriya Jan 23 '16 at 10:19
  • @Pablo, sorry I meant yes. – N.S.JOHN Jan 23 '16 at 10:21
  • @N.S.JOHN - Try rephrasing your question so that you put a limit on the upper bound of the eccentricity to be something like 0.001 or some other small number. The limit will never go to zero for the reasons stated above by others, but it can get small (e.g., Earth's orbital eccentricity is ~0.017). Or you could put a limit on the deviation from unity of the ratio of the semi-major to semi-minor axes lengths. Either way, it would make answering your question possible... – honeste_vivere Feb 08 '16 at 14:44
  • @honest_covers surely but I have cleared the doubt. – N.S.JOHN Feb 08 '16 at 14:46

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