With reference to Orbital variables. I may tack on a few more significant digits in places than are really warranted.
To consider also: 4179 Toutatis
![{\displaystyle M_{Sun}=1.989\times 10^{30}{\mbox{kg}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/7e6b0dc623f09009fd8cace255c9d910cbca44d6)
![{\displaystyle \mu \equiv M_{Sun}G=1.327178\times 10^{20}{{\mbox{m}}^{3} \over {\mbox{s}}^{2}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ed137ae7cb9551737ba0ddbea76a0c152ec70d16)
![{\displaystyle 590,000{\mbox{m}}\leq r_{Sedna}\leq 1,180,000{\mbox{m}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/60c618f3add3645c95628b03015be6d44f89b21a)
![{\displaystyle 1,180,000{\mbox{m}}\leq d_{Sedna}\leq 2,360,000{\mbox{m}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/00c223fb39ee909db80d79b9ebe798cb10bf9697)
Assuming density equal to Pluto,
![{\displaystyle 1.76\times 10^{21}{\mbox{kg}}\leq M_{Sedna}\leq 1.41\times 10^{22}{\mbox{kg}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e3fdad272ab503b1a059c6f73b4ef9ddcb53d8ed)
![{\displaystyle a=463{\mbox{AU}}=6.93\times 10^{13}{\mbox{m}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ab09346461bdf2df84f7615814416761f118b4ac)
![{\displaystyle T=10,500{\mbox{yr}}=3.31\times 10^{11}{\mbox{s}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5063e846d4bcbf071b2ed86e56be5a55c6ad5cf4)
![{\displaystyle \left|\mathbf {h} \right|=5.263\times 10^{16}{{\mbox{m}}^{2} \over {\mbox{s}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ecc772c332bb0b358132378bef1b1e98607b0ebc)
![{\displaystyle {\mathcal {E}}_{orbital}=-958,000{{\mbox{m}}^{2} \over {\mbox{s}}^{2}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/1a1f111cfcb99f47af543145d901add0c6260c67)
![{\displaystyle R_{peri}=76\pm 7{\mbox{AU}}=1.137\times 10^{13}\pm 0.105\times 10^{13}{\mbox{m}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e43512e44368870e25bd010ab5956036747723f5)
![{\displaystyle v_{peri}\equiv {\left|\mathbf {h} \right| \over R_{peri}}=4629{{\mbox{m}} \over {\mbox{s}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/81d75143995296022d4aa534971a3401686ab172)
![{\displaystyle {\mathcal {E}}_{grav,peri}=11,700,000{{\mbox{m}}^{2} \over {\mbox{s}}^{2}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/8540f605f7f2d9d395fb49392a950edf86f83bf8)
![{\displaystyle {\mathcal {E}}_{kinetic,peri}=10,700,000{{\mbox{m}}^{2} \over {\mbox{s}}^{2}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/54dcdd063aa4914c79c62f7b364650e48b04672a)
![{\displaystyle R_{ap}=850{\mbox{AU}}=1.27\times 10^{14}{\mbox{m}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/9d83312af151ad69a7f3813cdcaeb1922c650642)
![{\displaystyle v_{ap}\equiv {\left|\mathbf {h} \right| \over R_{ap}}=414{{\mbox{m}} \over {\mbox{s}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/b586e63fdad5a7bce21d72055aacbdeadb217ca1)
![{\displaystyle {\mathcal {E}}_{grav,ap}=1,040,000{{\mbox{m}}^{2} \over {\mbox{s}}^{2}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/b3b7993bc7b0c3707a51cfc0784ab7f005ab1da7)
![{\displaystyle {\mathcal {E}}_{kinetic,ap}=85,700{{\mbox{m}}^{2} \over {\mbox{s}}^{2}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/cd71ecf7ac9e7fea3d264fc0bde98cb45df7c325)
![{\displaystyle R_{now}=90{\mbox{AU}}=1.35\times 10^{13}{\mbox{m}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c4e8ae8636fc5bceef7baf212698d1f6cecb1f90)
![{\displaystyle v_{now}=4,219{{\mbox{m}} \over {\mbox{s}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/fff440f6a92723fb45938550b59bee9d2865bc87)
![{\displaystyle {\mathcal {E}}_{grav,now}=9,857,000{{\mbox{m}}^{2} \over {\mbox{s}}^{2}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/92b335ae6d21210c0932d92ed4f047bb8686e1da)
![{\displaystyle {\mathcal {E}}_{kinetic,now}=8,899,000{{\mbox{m}}^{2} \over {\mbox{s}}^{2}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/75823b75c9e450c2f332af603de0643fa3e11714)
Unrelated, I just need a place to stick it:
(c*dT)^2 = (1-2*G*M/c^2/r)*(c*dt)^2 - (1-2*G*M/c^2/r)^-1*dr^2 - r^2*dtheta^2 - r^2*sin^2(theta)*dphi^2