We use three campaigns of K2 observations to complete the census of rotation in low-mass members of the benchmark, ~=670Myr old open cluster Praesepe. We measure new rotation periods (Prot) for 220 ~95% of the 331 likely single stars with >=2 high-quality observations; the median difference in Prot is 0.3%, with a standard deviation of 2%. Nearly all of the exceptions are stars with discrepant Prot measurements in Campaign 18, K2's last, which was significantly shorter than the earlier two (~=50 days rather than ~=75 days). This suggests that, despite the evident morphological evolution we observe in the light curves of 38% of the stars, Prot measurements for low-mass stars in Praesepe are stable on timescales of several years. A Prot can therefore be taken to be representative even if measured only once.

Cone search capability for table J/ApJ/921/167/table4 (Rotators in Praesepe)

Cone search capability for table J/ApJ/921/167/table3 (Lomb-Scargle outputs for the Praesepe rotators)