Although perihelion was Sept 28, 2006,[1] the comet flared dramatically from seventh magnitude to fourth magnitude on October 24, 2006, becoming visible with the naked eye.[4]
Comet C/2006 M4 is in a hyperbolic trajectory (with an osculating eccentricity larger than 1)[1] during its passage through the inner Solar System. After leaving the influence of the planets, the eccentricity will drop below 1 and it will remain bound to the Solar System as an Oort cloud comet.
Given the extreme orbital eccentricity of this object, different epochs can generate quite different heliocentric unperturbed two-bodybest-fit solutions to the aphelion distance (maximum distance) of this object. For objects at such high eccentricity, the Suns barycentric coordinates are more stable than heliocentric coordinates. Using JPL Horizons, the barycentric orbital elements for epoch 2013-May-14 generate a semi-major axis of about 1300 AU and a period of about 47,000 years.[2]