237 year & 913 year Orbital Cycles ... (19 May 2023)
There are several important planetary orbital cycles: The 19 year cycle, the 237 year cycle, and the 913 year cycle.
The more commonly observed planetary cycle is 59 years, which corresponds quite closely to 5 orbits of Jupiter and 2 orbits of Saturn. And more famously there is a 19 year cycle which corresponds almost precisely with 254 orbits of the moon. (Vital to comprehending the Antikythera mechanism).
But until this study, there was no evidence of the 237 year cycle, and the 913 year cycle.