In the same way that the sunlight's spectrum (or at least the part of it that reaches the Earth's surface) has the most energy of green wavelengths, which are conveniently in the middle of the light spectrum visible by humans.
The barycentre of Sun-Jupiter system is outside of the Sun half the time. It's a really bad metric for determining that, as it depends on the distance between two bodies and not just on their relative masses.
Because he must be feeling pretty blue these last few years