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We announce the detection of recurring sets of recurring starspot occultationevents in the short-cadence K2 lightcurve of Qatar-2, a K dwarf star transitedevery 1.34 d by a hot Jupiter. In total we detect 34 individual starspotoccultation events, caused by five different starspots, occulted in up to fiveconsecutive transits or after a full stellar rotation. The longest recurringset of recurring starspot occultations spans over three stellar rotations,setting a lower limit for the longest starspot lifetime of 58 d. Starspotanalysis provided a robust stellar rotational period measurement of$18.0\pm0.2$ d and indicates that the system is aligned, having a sky-projectedobliquity of $0\pm8^{\circ}$. A pronounced rotational modulation in thelightcurve has a period of $18.2\pm1.6$ d, in agreement with the rotationalperiod derived from the starspot occultations. We tentatively detect anellipsoidal modulation in the phase-curve, with a semi-amplitude of 18 ppm, butcannot exclude the possibility that this is the result of red noise orimperfect removal of the rotational modulation. We detect no transit-timing andtransit-duration variations with upper limits of 15 s and 1 min, respectively.We also reject any additional transiting planets with transit depths above 280ppm in the orbital period region 0.5-30 d.

Recurring sets of recurring starspot occultations on exoplanet-host Qatar-2