# Summary of K2 Program GO13111 Title: The grand K2 RR Lyrae survey PI: Molnar, Laszlo (Konkoly Observatory) CoIs: Kollmeier, Juna A; Plachy, Emese; Szabo, Robert; Netzel, Henryka; Magnier, Eugene A; Smolec, Radoslaw; Pal, Andras; Flewelling, Heather A; Kolenberg, Katrien RR Lyrae stars play a crucial role in astrophysics as standard candles, tracers of galactic history, and touchstones for modeling stellar pulsations. Space data of these crucial objects have led to a giant leap forward in our understanding of their structure and evolution through the discovery of new dynamical phenomena. Moreover, insight into these stars dynamics is of crucial importance to advance our knowledge of galaxy formation and evolution in the Local Group of galaxies and beyond. Throughout the K2 Mission we have been building up a unique database of high precision RR Lyrae light curves from field to field, covering different parts of our Galaxy, and beyond. Our strategy assures that galactic structure studies and statistical analysis of pulsation properties (double-mode pulsation, Blazhko modulation, period doubling, low-dimensional chaos, non-radial modes) based on K2 data will be possible. Besides the ensemble studies, the boutique analysis of individual stars will be equally interesting and important. Targets --------- Field 11 covers parts of the bulge where tens of thousands of RR Lyrae stars reside. For this proposal we selected about 1200 stars based on the OGLE-IV survey and an additional 400 stars from other sources covering the rest of the field of view. The OGLE survey discovered many stars with peculiar pulsation and modulation properties. Low-amplitude additional modes have been observed in all RR Lyrae subtypes, but their origins and occurrence rates are still largely unknown. We also included modulated RRc stars in the list. While the Blazhko effect in fundamental-mode stars has been studied extensively from space, the sample of modulated RRc stars is still scarce. In Field 12 we selected about 200 stars. 8 RR Lyrae stars were previously observed during the K2-E2 Engineering Test run, including a fundamental-mode star where we tentatively identified a frequency component as a g-mode signal. Re-observation of these targets present a unique opportunity to reassess our earlier findings that were based on only 9 days of data. It will also show us how did the accuracy of Kepler evolve since the early tests. For a number of RR Lyrae stars extensive multicolor photometry is available from the Pan-STARRS Medium Deep Field survey. The detailed color information will be a valuable addition to the K2 light curves. Beside the RR Lyrae stars, we also found an additional 30 variables belonging to various classes that we also include in this proposal. Field 13, towards the Galactic anticenter direction, contains 103 known RR Lyrae stars. One priority target here is BR Tau that has a short modulation period of only ~19 days. Methods and planned community resources --------------------------------------------------- Standard time-frequency analysis (by e.g. Period04) and study of time-dependent features are envisaged. Metallicities will be derived from empirical relations calibrated with high-resolution spectra. State-of-the-art numerical hydrocodes (Florida-Budapest, Warsaw) will be used to interpret the results. Synthetic galactic models (TRILEGAL) will be used to compare the galactic location and number of the observed sample with simulations. Photometry of large-amplitude pulsators require special treatment, and general-purpose pipelines may provide RR Lyrae light curves with sub-optimal quality. We already released tailor-made photometry from some Kepler data sets. We intend to create custom light curves for the stars listed in this proposal too, and plan to employ special methods like differential-image photometry for the bulge field. As a value-added community resource we envisage a searchable database containing the light curves, frequency solutions and other parameters (Blazhko periods, additional modes, etc.) of the RR Lyrae stars observed by K2. # Targets requested by this program that have been observed (90) EPIC ID, RA (J2000) [deg], Dec (J2000) [deg], magnitude, Investigation IDs 210648816, 66.331496, 17.652293, 18.579, GO13111_LC 210654899, 66.810294, 17.736759, 18.963, GO13111_LC 210676540, 66.204739, 18.033227, 18.721, GO13111_LC 210739713, 66.577806, 18.95301, 15.757, GO13111_LC|GO13902_LC|GO13904_LC 210754711, 66.567775, 19.182075, 16.663, GO13111_LC|GO13902_LC|GO13904_LC 210766289, 65.66354, 19.357075, 16.398, GO13111_LC|GO13902_LC|GO13904_LC 210799616, 67.216501, 19.8624, 18.071, GO13111_LC 210831853, 65.87982, 20.353701, 17.153, GO13111_LC 210862813, 65.759455, 20.820553, 16.312, GO13111_LC 210872065, 66.288593, 20.959254, 16.016, GO13111_LC 210908689, 65.650881, 21.526576, 19.035, GO13111_LC 210934522, 66.9177, 21.936791, 15.477, GO13111_LC 220115973, 66.3701782, 19.5589905, 19.73, GO13111_LC 246623633, 71.820234, 13.54665, 17.847, GO13111_LC 246691697, 74.295212, 14.467372, 19.603, GO13111_LC 246785473, 78.466359, 15.583502, 13.367, GO13049_LC|GO13122_LC|GO13111_LC 246786436, 78.235588, 15.593631, 18.066, GO13111_LC 246789347, 78.813919, 15.625519, 17.326, GO13111_LC 246820469, 79.061005, 15.957747, 11.845, GO13071_LC|GO13122_LC|GO13111_LC 246851302, 78.490542, 16.274752, 14.774, GO13111_LC 246872772, 75.303577, 16.488167, 17.71, GO13111_LC 246912519, 76.601616, 16.873901, 17.926, GO13111_LC 246917989, 76.607229, 16.927691, 15.866, GO13111_LC 246932763, 76.932607, 17.071406, 15.703, GO13111_LC 247033375, 73.357129, 18.03476, 17.984, GO13111_LC 247050596, 74.970874, 18.200516, 14.742, GO13111_LC 247056872, 74.128851, 18.259985, 15.54, GO13111_LC|GO13019_LC 247061553, 74.200207, 18.304445, 11.408, GO13071_LC|GO13122_LC|GO13024_LC|GO13111_LC 247070019, 74.43139, 18.384221, 14.558, GO13111_LC 247162240, 71.033103, 19.263632, 16.526, GO13111_LC 247163350, 69.078885, 19.274584, 18.08, GO13111_LC 247230439, 71.060449, 19.913078, 17.234, GO13111_LC 247269360, 73.952225, 20.275068, 17.803, GO13111_LC 247271295, 69.622642, 20.29246, 19.879, GO13111_LC 247334376, 78.638139, 20.852724, 17.569, GO13111_LC 247359184, 68.526546, 21.063087, 19.184, GO13111_LC 247374553, 73.712337, 21.189704, 15.654, GO13111_LC 247398225, 71.398565, 21.38224, 17.99, GO13111_LC 247436262, 74.596495, 21.691088, 13.638, GO13122_LC|GO13111_LC 247446215, 68.678819, 21.772699, 12.931, GO13071_LC|GO13111_LC 247504420, 68.08357, 22.229076, 19.934, GO13111_LC 247520086, 74.535403, 22.349961, 13.671, GO13122_LC|GO13111_LC|GO13070_LC 247535910, 72.412914, 22.470014, 19.717, GO13111_LC 247554980, 71.102847, 22.617196, 12.739, GO13071_LC|GO13122_LC|GO13002_LC|GO13111_LC 247672771, 70.718492, 23.513281, 16.157, GO13111_LC 247715790, 75.500595, 23.824521, 16.091, GO13111_LC 247724949, 73.571991, 23.888307, 15.06, GO13111_LC 247755596, 72.5761, 24.101698, 17.301, GO13111_LC 247763502, 70.821603, 24.156761, 16.453, GO13111_LC 247776031, 75.855812, 24.243093, 16.917, GO13111_LC 247811730, 72.117885, 24.490116, 17.824, GO13111_LC 247853291, 72.041069, 24.774831, 19.474, GO13111_LC 247945902, 68.400811, 25.414495, 16.933, GO13111_LC 248152409, 70.284708, 27.041889, 18.098, GO13111_LC 251456989, , , , GO13111_LC 251456990, , , , GO13111_LC 251456991, , , , GO13111_LC 251456992, , , , GO13111_LC 251456993, , , , GO13111_LC 251456994, , , , GO13111_LC 251456995, , , , GO13111_LC 251456996, , , , GO13111_LC 251456997, , , , GO13111_LC 251456998, , , , GO13111_LC 251456999, , , , GO13111_LC 251457000, , , , GO13111_LC 251457001, , , , GO13111_LC 251457002, , , , GO13111_LC 251457003, , , , GO13111_LC 251457005, , , , GO13111_LC 251457006, , , , GO13111_LC 251457007, , , , GO13111_LC 251457008, , , , GO13111_LC 251457009, , , , GO13111_LC 251457010, , , , GO13111_LC 251457011, , , , GO13111_LC 251457012, , , , GO13111_LC 251457013, , , , GO13111_LC 251457014, , , , GO13111_LC 251457015, , , , GO13111_LC 251457016, , , , GO13111_LC 251457017, , , , GO13111_LC 251457018, , , , GO13111_LC 251457019, , , , GO13111_LC 251457020, , , , GO13111_LC 251457021, , , , GO13111_LC 251457022, , , , GO13111_LC 251457023, , , , GO13111_LC 251457024, , , , GO13111_LC 251457025, , , , GO13111_LC