Four ‘Peculiar’ RRd stars observed by K2

Four stars pulsating simultaneously with a dominant period $P_D$$\in$(0.28,0.39) d and an {\it additional} $P_A$$\in$(0.20,0.27) have been identified from among the more than 3000 RR Lyrae observed by Kepler space telescope during NASA's K2 Mission. All four are located in direction of Galactic Bulge ratios, $P_A$/$P_D$, significantly smaller those most double-mode (RRd) stars: $P_A$/$P_D$$\in$(0.694,0.710) vs. $P_1$/$P_0$$\in$(0.726,0.748). Three faint ($<$$V$$>$=18--20 mag) distant `peculiar' RRd (pRRd) discovered Prudil et al. (2017); fourth star, EPIC 216764000 (=V1125 Sgr), is newly pRRd star several magnitudes brighter other three stars. In this paper high-precision long-cadence photometry analyzed detail used to study cycle-to-cycle light variations. The pulsational characteristics compared `classical' `anomalous' (cRRd, aRRd) conclusion that form separate group pulsators not simply very-short-period cRRd confirmed. V1127 Aql AH Cam as probable members class