After decades of effort, the solar activity cycle is exceptionally wellcharacterized but it remains poorly understood. Pioneering work at the MountWilson Observatory demonstrated that other sun-like stars also show regularactivity cycles, and suggested two possible relationships between the rotationrate and the length of the cycle. Neither of these relationships correctlydescribe the properties of the Sun, a peculiarity that demands explanation.Recent discoveries have started to shed light on this issue, suggesting thatthe Sun's rotation rate and magnetic field are currently in a transitionalphase that occurs in all middle-aged stars. Motivated by these developments, weidentify the manifestation of this magnetic transition in the best availabledata on stellar cycles. We propose a reinterpretation of previously publishedobservations to suggest that the solar cycle may be growing longer on stellarevolutionary timescales, and that the cycle might disappear sometime in thenext 0.8-2.4 Gyr. Future tests of this hypothesis will come from ground-basedactivity monitoring of Kepler targets that span the magnetic transition, andfrom asteroseismology with the TESS mission to determine precise masses andages for bright stars with known cycles.
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