What is the Orbital Period of Eris, the Tenth Planet?

[leonne]

Homework Statement

We will compute the orbit of Eris, the infamous \tenth planet" that caused Pluto
to be demoted to \dwarf planet" status. Eris (also called 2003 UB313 in the
textbook) has a semimajor axis a = 68:048 AU and eccentricity e = 0:4336 based
on the best current observations. Calculate the orbital period P of Eris (in years).

Homework Equations

P^2=4pie^2)/G(m1+m2)) (a1+a2)^3

The Attempt at a Solution

would i just use this formula? I know it would work but not sure if i am suppose to use something else cause i was given eccentricity, but could not find any formula that uses it to find orbital period

 

[zhermes]

The period does not depend on the eccentricity (kepler's third law).

 

[leonne]

yea i figured that out thxs, eccentricity was for the other part of the problem