# Summary of K2 Program GO7043

Title: A search for exoplanets and close stellar/substellar companions in the local
halo population for K2 campaigns 6-7

PI: Lepine, Sebastien (Georgia State University)
CoIs: Jao, Wei-Chun

We propose to expand the scope of the original Kepler mission by conducting a systematic search for exoplanets orbiting the very old stars of the Galactic halo, a population of stars that was not targeted to any significant degree in the original Kepler mission. Following the recent discovery of exoplanets orbiting Kapteyn's star, a known local halo M subdwarf, and the determination of a very old age (~10Gyr) for the exoplanet bearing star Kepler-10, it is now suspected that stars of the Galactic halo population also harbor exoplanets in significant numbers. However, very little is know about the prevalence and properties of exoplanets orbiting old metal-poor stars because this population has been largely overlooked by most exoplanet surveys. However, our astrometric and photometric analysis of the fields to be observed in campaigns 6-7 of the Kepler K2 mission identifies 2,709 high-velocity subdwarfs that are unambiguous members of the local Galactic halo. We propose to monitor these halo stars with Kepler, to identify and characterize the first generation of exoplanets in our Galaxy. Light curves of the targeted halo stars will be searched for eclipses or transits, following the methodologies developed in the first Kepler mission. Candidates will be targeted for ground-based, follow-up observations to confirm the existence of the transit, and determine if it is from a planet of from a stellar companion. The detection of eclipsing stellar companions would also be of high interest for stellar astrophysics, as it would provide natural calibrators of the mass-radius relationship; while this relationship is critical to constrain models of stellar structure, such calibrators currently do not exist for low-mass, metal-poor stars. Relevance: this program will directly expand on the original goal of Kepler to find exoplanets orbiting main sequence stars in the Galactic disk. The data collected on local Galactic halo stars will be complement existing result from the Kepler mission by providing statistics and/or properties of exoplanets orbiting old, metal-poor stars.

# Targets requested by this program that have been observed (154)
EPIC ID, RA (J2000) [deg], Dec (J2000) [deg], magnitude, Investigation IDs
213422772, 289.1530151, -29.4786987, 16.282, GO7071_LC|GO7043_LC
213424483, 289.1477966, -29.4725494, 14.869, GO7071_LC|GO7043_LC
213425035, 289.1327209, -29.4705296, 16.214, GO7071_LC|GO7043_LC
213478883, 290.721405, -29.2806873, 14.506, GO7071_LC|GO7043_LC
213800086, 289.6065674, -28.2393608, 13.978, GO7032_LC|GO7043_LC
213823705, 282.2116089, -28.1687946, 16.255, GO7071_LC|GO7043_LC
213910447, 290.8534241, -27.9123974, 14.909, GO7071_LC|GO7043_LC
214216164, 293.532959, -27.0652008, 16.71, GO7071_LC|GO7043_LC
214343312, 286.3728943, -26.7314816, 16.165, GO7071_LC|GO7043_LC
214352487, 289.1789551, -26.7078686, 15.276, GO7043_LC
214354780, 283.3051758, -26.7021828, 17.836, GO7043_LC
214360548, 287.8882751, -26.6872978, 17.712, GO7043_LC
214362400, 281.1270752, -26.6825905, 16.763, GO7008_LC|GO7043_LC
214367898, 288.5713501, -26.6685658, 16.664, GO7043_LC
214374349, 288.5525818, -26.6520519, 13.821, GO7043_LC
214391149, 283.1760254, -26.6098042, 16.641, GO7043_LC
214395241, 286.2346802, -26.5993156, 17.425, GO7043_LC
214397294, 290.3965454, -26.5940132, 14.122, GO7043_LC
214436018, 290.3863525, -26.4975739, 17.741, GO7043_LC
214445345, 288.2976379, -26.4742832, 14.328, GO7043_LC
214446028, 290.0808411, -26.4725857, 15.461, GO7043_LC
214457260, 293.3104858, -26.4447536, 18.173, GO7043_LC
214479230, 285.8322144, -26.3902912, 18.588, GO7043_LC
214483213, 293.2927551, -26.3804798, 18.022, GO7043_LC
214513408, 287.6834717, -26.3071995, 16.692, GO7043_LC
214521201, 289.6157227, -26.2878551, 17.825, GO7043_LC
214530567, 282.0705872, -26.2647629, 17.412, GO7043_LC
214547615, 285.2932739, -26.2227726, 17.371, GO7043_LC
214606056, 286.5700684, -26.0796356, 15.305, GO7071_LC|GO7043_LC
214615132, 282.3833008, -26.0574989, 16.279, GO7043_LC
214624698, 286.6183167, -26.0343399, 17.913, GO7043_LC
214648242, 281.644165, -25.977129, 16.042, GO7043_LC
214666243, 286.2190247, -25.9330559, 17.758, GO7043_LC
214727286, 290.2521973, -25.7861328, 16.857, GO7043_LC
214733184, 288.5874939, -25.772028, 18.178, GO7043_LC
214747292, 289.0410461, -25.7388897, 17.485, GO7043_LC
214768237, 287.9286499, -25.6897449, 18.188, GO7043_LC
214784432, 281.0560303, -25.6516228, 18.148, GO7043_LC
214797252, 289.8855286, -25.6212521, 18.874, GO7043_LC
214801578, 282.3042603, -25.6113377, 18.189, GO7043_LC
214822977, 288.0706482, -25.5617619, 17.862, GO7043_LC
214828099, 286.7471313, -25.5498104, 17.829, GO7043_LC
214930516, 288.8922729, -25.3144932, 15.076, GO7043_LC
214952645, 288.22995, -25.2642746, 18.603, GO7043_LC
214998343, 284.6984253, -25.1624794, 17.544, GO7043_LC
215057490, 294.2960815, -25.0325127, 18.269, GO7043_LC
215061257, 288.5934753, -25.0240383, 17.285, GO7043_LC
215085103, 283.8608093, -24.9713306, 16.749, GO7043_LC
215093340, 285.6038818, -24.9530296, 17.029, GO7043_LC
215106360, 285.0137024, -24.924696, 18.443, GO7043_LC
215154381, 295.0320435, -24.8206921, 18.606, GO7043_LC
215158311, 295.4739075, -24.8120937, 17.172, GO7043_LC
215202178, 282.8133545, -24.7178345, 16.283, GO7043_LC
215238087, 285.8829041, -24.6406174, 18.001, GO7043_LC
215244055, 296.1980591, -24.6278858, 17.935, GO7043_LC
215245088, 294.2778015, -24.6257954, 18.177, GO7043_LC
215246147, 294.3825684, -24.6235123, 16.956, GO7043_LC
215248271, 285.1202698, -24.6188755, 18.207, GO7043_LC
215250036, 281.0787354, -24.6152897, 13.523, GO7043_LC
215317224, 294.5774536, -24.4726086, 17.694, GO7043_LC
215344447, 296.3197937, -24.4154625, 18.489, GO7043_LC
215351657, 296.0169373, -24.4002838, 16.894, GO7071_LC|GO7043_LC
215352353, 296.0142212, -24.3988552, 15.869, GO7071_LC|GO7043_LC
215356384, 287.6422729, -24.3905239, 17.682, GO7043_LC
215361160, 294.0914307, -24.3804569, 17.788, GO7043_LC
215368175, 285.9735718, -24.3656521, 17.203, GO7043_LC
215376966, 282.1641846, -24.347023, 17.815, GO7043_LC
215380297, 296.1678162, -24.3401165, 17.64, GO7043_LC
215386011, 285.1077881, -24.3283672, 16.501, GO7043_LC
215407686, 294.6994324, -24.2832127, 17.672, GO7043_LC
215458173, 295.7504883, -24.1772804, 18.256, GO7043_LC
215516224, 285.1400146, -24.0557404, 17.489, GO7043_LC
215529739, 289.3144531, -24.0274906, 17.759, GO7043_LC
215536137, 293.5293274, -24.0139999, 17.338, GO7043_LC
215536879, 295.818634, -24.012434, 15.878, GO7043_LC
215586659, 289.2844849, -23.9192505, 18.242, GO7043_LC
215637241, 289.0583801, -23.8262959, 17.642, GO7043_LC
215649254, 289.3037109, -23.8031197, 17.023, GO7043_LC
215670169, 290.0237732, -23.7628155, 17.401, GO7043_LC
215685244, 288.0921936, -23.7342396, 18.084, GO7043_LC
215690395, 293.83078, -23.7245216, 17.275, GO7043_LC
215697028, 284.7671814, -23.7119236, 17.699, GO7043_LC
215705658, 295.1997681, -23.6957741, 17.916, GO7043_LC
215719239, 293.3720093, -23.6701851, 16.398, GO7043_LC
215726783, 294.5101013, -23.6558952, 18.561, GO7043_LC
215736884, 284.7007751, -23.6366367, 18.183, GO7043_LC
215758296, 294.7628174, -23.596365, 17.863, GO7043_LC
215771197, 293.3777771, -23.5719891, 18.419, GO7043_LC
215782557, 288.617981, -23.5506859, 16.858, GO7043_LC
215882647, 286.4701538, -23.3632488, 18.433, GO7043_LC
215924339, 295.7697449, -23.285944, 18.023, GO7043_LC
215926621, 294.1891785, -23.2818069, 18.122, GO7043_LC
215981793, 282.2902222, -23.1797142, 16.595, GO7043_LC
215987096, 285.6967468, -23.1698875, 17.96, GO7043_LC
215987662, 285.1449585, -23.1688557, 16.403, GO7043_LC
215994637, 295.7613525, -23.156044, 16.8, GO7043_LC
216003253, 285.4077454, -23.1400394, 17.923, GO7043_LC
216045083, 293.992981, -23.0628071, 17.027, GO7043_LC
216068006, 287.9067688, -23.0207233, 17.877, GO7043_LC
216069920, 286.6851196, -23.0170441, 18.864, GO7043_LC
216074467, 282.0253296, -23.0087547, 16.494, GO7043_LC
216113395, 289.9828796, -22.9374142, 18.259, GO7043_LC
216136486, 283.8411255, -22.8953075, 18.308, GO7043_LC
216150440, 291.6832886, -22.8701973, 18.248, GO7043_LC
216154753, 295.1464539, -22.8623295, 17.902, GO7043_LC
216158095, 290.374176, -22.8562851, 14.699, GO7071_LC|GO7043_LC
216174927, 288.4184875, -22.8257313, 17.85, GO7043_LC
216181910, 290.6127014, -22.8132038, 17.709, GO7043_LC
216215114, 281.7267456, -22.7524433, 18.105, GO7043_LC
216267448, 289.5140686, -22.6555996, 18.349, GO7043_LC
216271904, 289.5975952, -22.6473522, 17.971, GO7043_LC
216282436, 290.4891663, -22.6281986, 17.869, GO7043_LC
216336373, 291.0286865, -22.5306091, 17.732, GO7043_LC
216346454, 287.2584534, -22.5124378, 17.814, GO7043_LC
216364162, 287.7263184, -22.4809303, 18.007, GO7043_LC
216368635, 291.3533325, -22.4729691, 15.88, GO7071_LC|GO7043_LC
216372931, 281.5060425, -22.4652958, 17.99, GO7043_LC
216376465, 291.7613525, -22.4588795, 16.054, GO7043_LC
216381554, 287.0235291, -22.4499054, 18.561, GO7043_LC
216397428, 295.2390747, -22.4211693, 17.961, GO7043_LC
216458696, 283.2754517, -22.3112183, 17.472, GO7043_LC
216458934, 287.5046082, -22.3107815, 17.39, GO7043_LC
216502394, 291.0725708, -22.2329941, 17.938, GO7043_LC
216503866, 292.0343628, -22.2303791, 19.005, GO7043_LC
216507447, 290.2851868, -22.2240334, 18.367, GO7043_LC
216525185, 284.9906311, -22.1923542, 17.163, GO7043_LC
216541229, 289.7585144, -22.1637154, 18.366, GO7043_LC
216573011, 288.3172913, -22.1068687, 17.879, GO7043_LC
216630925, 290.6596985, -22.0035572, 17.045, GO7043_LC
216653697, 291.5415955, -21.9633827, 16.528, GO7043_LC
216696408, 291.1896973, -21.8878841, 16.7, GO7043_LC
216698737, 291.696167, -21.8836765, 17.393, GO7043_LC
216716926, 286.4262085, -21.8512726, 16.107, GO7043_LC
216752128, 291.3050232, -21.7886696, 17.936, GO7043_LC
216756275, 285.1826782, -21.7812881, 17.989, GO7043_LC
216800363, 290.7652588, -21.7023792, 18.138, GO7043_LC
216818519, 284.8344421, -21.6698647, 18.135, GO7043_LC
216826445, 286.2807007, -21.6557865, 16.892, GO7043_LC
216878161, 290.9095764, -21.5638142, 17.146, GO7043_LC
216887314, 286.1516418, -21.5475464, 17.847, GO7043_LC
217095075, 290.5336304, -21.180727, 17.758, GO7043_LC
217183010, 289.1305542, -21.0253448, 18.522, GO7043_LC
217235443, 288.8528748, -20.9319115, 18.347, GO7043_LC
217643368, 284.6090698, -20.2154808, 13.853, GO7071_LC|GO7043_LC
217742774, 289.2821045, -20.0408955, 16.506, GO7071_LC|GO7043_LC
217748677, 289.2895203, -20.0304203, 16.321, GO7071_LC|GO7043_LC
217943233, 288.4342041, -19.688036, 12.752, GO7086_LC|GO7030_LC|GO7071_LC|GO7043_LC
218419198, 291.8948975, -18.8366699, 17.151, GO7071_LC|GO7043_LC
218924275, 292.8641357, -17.8970127, 12.356, GO7086_LC|GO7030_LC|GO7043_LC
219083231, 287.5665588, -17.5624695, 17.258, GO7071_LC|GO7043_LC
229228153, , , , GO7043_LC
229228308, , , , GO7043_LC
229228312, , , , GO7043_LC
229228357, , , , GO7043_LC