the sun - Are we sure solar cycle is not related to the orbit of Jupiter?

The barycenter of the Solar System is the effect which should be considered physically. Although dominated by Jupiter other planets have substantial effect too, moving the Sun, with 99+% of all mass in the Solar System, around by entire Solar radii (700,000 km). Illustrated here

The diagram below I happened to stumble upon here. It shows the distance of the barycenter of the Solar System from the center of the Sun over time, with years on the circle. For some reason it spans from year 1773 to 1851. The peaks in the clover curve are regularly separated by about a sunspot cycle, or rather a bit longer. I suppose that the pattern of 2 big and 1 small sequential bulbs there reflects that Jupiter's and Saturn's orbital periods are about 3:1.

As StephenG says, that is just a numerological hint or coincidence, not an explanation. Another example is that the rotational period of the Sun is roughly similar to the orbital period of the Moon around Earth, with a similar error, but no one imagines any connection there.

It is however known that hot Jupiters, giant planets near stars, cause large starspots which rotate along with the planet's orbit. And the relatively tiny moons of Jupiter cause visible spots in the planetary aurora. Actually, the Sun causes an auroral "Jupiter spot"! So there are physics around which under certain conditions create sunspot-like effects.

Diagram: Barycenter distance from the Sun's center over time

Hubble image:The aurora on a pole of Jupiter in UV