An extra-solar planet moes in an elliptic orbit around a star of mass M. The max distance between the planet and the star is known to be r2 = 8r1 where r1 is the min distance between the planet and the star. a) What is the eccentricity of the planet's orbit? b) What is the period of the planet's orbit in terms of the distance r1 and the mass of the star? c) Compute the numerical value of the ratio of the planet's max speed to the planet's min speed. a) r min = r1 = a(1-e) r max = r2 = a(1+e) but rmax = 8rmin a(1+e) = 8a(1-e) and continue... e = 7/9 b) I suppose you can use kepler's third law T^2 = (4*pie^2*a^3)/GM a = r1/(1-e) = r1/(2/9) =r1= 9r1/2 T^2 = [4*pie^2 *(9r1/2)^3]/GM T = 27pie sqrt[r1^3/(2GM)] was this the right approach? c) how do I begin with part c?