# Summary of K2 Program GO7084

Title: Giants Orbiting Giants: A Search for Transiting Planets around Oscillating Red-Giant Branch Stars with K2

PI: Huber, Daniel (SETI Institute)
CoIs: Pinsonneault, Marc Howard; Johnson, John Asher; Gaidos, Eric; Lopez, Eric David; Mann, Andrew Withycombe; Chaplin, William J; Fortney, Jonathan J

Science Goals and Objectives: While exoplanet transit surveys are increasingly focused on cool dwarfs, transiting planets orbiting red-giant branch (RGB) stars are largely unexplored. Due to their diversity in fundamental properties (masses, luminosities, chemical compositions), RGB stars are ideal targets to tackle two key unsolved questions in exoplanet science: the occurrence rate of gas-giant planets as a function of host star mass, and the role of stellar incident flux on the radius inflation of gas-giant planets. We propose a survey of ~2000 low-luminosity RGB stars (with radii between ~3.5-8 solar radii) using long-cadence data to detect transiting gas-giant planets with K2 and address the above science questions by combining exoplanet transits and asteroseismology.

Methodology: Targets will be selected using colors and reduced proper motions. Planet candidates will be detected using a Box-Fitting Least Squares (BLS) algorithm coupled with a correlated noise model to account for stellar granulation. Since RGB stars oscillate with periods accessible with long-cadence data, we will use asteroseismology to precisely characterize both the host stars and the detected planet candidates. Follow-up ground-based radial velocity observations will be used to confirm the planet candidates. 

Relevance to Solicitation: The proposal addresses two main K2 science goals: exoplanet detection and stellar astrophysics. Due to the low number of K2 short-cadence slots, our survey is the only K2 program allowing a systematic combination of asteroseismology and transits to characterize exoplanets. Kepler was not optimized towards observing bright low-luminosity RGB stars, and hence new K2 observations are required to address the key science questions of this project.

# Targets requested by this program that have been observed (134)
EPIC ID, RA (J2000) [deg], Dec (J2000) [deg], magnitude, Investigation IDs
213364266, 290.2137756, -29.6927452, 13.459, GO7032_LC|GO7084_LC
213432065, 289.8056335, -29.4453659, 12.812, GO7032_LC|GO7084_LC
213435847, 290.6700134, -29.4317818, 13.73, GO7032_LC|GO7084_LC
213439627, 290.2325134, -29.4184761, 13.31, GO7032_LC|GO7084_LC
213473755, 290.4387207, -29.2985363, 13.307, GO7032_LC|GO7084_LC
213485121, 290.968811, -29.2590027, 13.728, GO7032_LC|GO7084_LC
213486289, 290.0019226, -29.2550964, 13.803, GO7032_LC|GO7084_LC
213488531, 289.5035095, -29.2469196, 13.638, GO7032_LC|GO7084_LC
213496028, 289.4302979, -29.2208385, 12.88, GO7032_LC|GO7084_LC
213496974, 289.971283, -29.2176132, 13.947, GO7032_LC|GO7084_LC
213497176, 290.5491333, -29.2170277, 13.027, GO7032_LC|GO7084_LC
213498382, 289.5569458, -29.213026, 13.676, GO7032_LC|GO7084_LC
213508255, 289.5599365, -29.1788387, 13.293, GO7032_LC|GO7084_LC
213508504, 289.0777283, -29.1779652, 13.707, GO7032_LC|GO7084_LC
213515239, 290.5452271, -29.1548004, 12.906, GO7032_LC|GO7084_LC
213518459, 289.4274292, -29.1435814, 12.688, GO7032_LC|GO7084_LC
213523476, 289.6933899, -29.1266708, 12.418, GO7032_LC|GO7084_LC
213527551, 290.0243835, -29.1126289, 12.14, GO7032_LC|GO7084_LC
213528908, 290.03125, -29.1079178, 12.57, GO7032_LC|GO7084_LC
213533540, 289.8024597, -29.0922108, 13.144, GO7032_LC|GO7084_LC
213539392, 290.7563782, -29.0724449, 12.502, GO7032_LC|GO7084_LC
213539932, 289.7539673, -29.0707226, 13.317, GO7032_LC|GO7084_LC
213541862, 291.1037598, -29.0642967, 13.926, GO7032_LC|GO7084_LC
213548228, 289.2728882, -29.0427132, 13.291, GO7032_LC|GO7084_LC
213575519, 289.0979919, -28.9516487, 13.26, GO7032_LC|GO7084_LC
213583885, 290.5850525, -28.9235554, 13.938, GO7032_LC|GO7084_LC
213591969, 289.1915588, -28.8973312, 13.094, GO7032_LC|GO7084_LC
213601209, 289.366394, -28.8667412, 13.838, GO7032_LC|GO7084_LC
213614021, 290.337677, -28.8243904, 11.848, GO7032_LC|GO7084_LC|GO7016_LC
213614882, 289.5538025, -28.8215809, 12.453, GO7032_LC|GO7084_LC
213617569, 291.103363, -28.8130264, 11.701, GO7032_LC|GO7084_LC
213628417, 289.2660828, -28.7773876, 12.667, GO7032_LC|GO7084_LC
213638949, 289.6952209, -28.7433662, 13.098, GO7032_LC|GO7084_LC
213639687, 287.2344055, -28.7410431, 7.826, GO7041_LC|GO7084_LC
213649499, 290.2824402, -28.7094421, 13.277, GO7032_LC|GO7084_LC
213654342, 289.0845337, -28.6939259, 12.233, GO7032_LC|GO7084_LC
213670870, 290.8442383, -28.6399879, 12.48, GO7032_LC|GO7084_LC
213675614, 290.769165, -28.6245823, 13.213, GO7032_LC|GO7084_LC
213689099, 289.6651001, -28.5818539, 13.115, GO7032_LC|GO7084_LC
213698261, 290.8161011, -28.5529785, 13.4, GO7032_LC|GO7084_LC
213707868, 289.3595276, -28.5231133, 13.38, GO7032_LC|GO7084_LC
213708436, 289.2144165, -28.5213108, 12.921, GO7032_LC|GO7084_LC
213710499, 290.87854, -28.5147667, 10.62, GO7032_LC|GO7084_LC
213716898, 289.3567505, -28.4943008, 13.4, GO7032_LC|GO7084_LC
213717948, 289.8432617, -28.4911366, 12.309, GO7032_LC|GO7084_LC
213728931, 289.9243774, -28.4569702, 13.196, GO7032_LC|GO7084_LC
213729739, 289.2173767, -28.4545879, 12.142, GO7032_LC|GO7084_LC
213729836, 289.7378235, -28.4542847, 13.588, GO7032_LC|GO7084_LC
213732624, 291.1226196, -28.4455967, 13.89, GO7032_LC|GO7084_LC
213736396, 290.6870422, -28.4336033, 13.518, GO7032_LC|GO7084_LC
213738801, 289.4594727, -28.4261513, 13.527, GO7032_LC|GO7084_LC
213778492, 290.2479248, -28.3047619, 13.715, GO7032_LC|GO7084_LC
213779688, 290.2041321, -28.3010254, 13.442, GO7032_LC|GO7084_LC
213793703, 289.221405, -28.2588024, 13.727, GO7032_LC|GO7084_LC
213801001, 289.81604, -28.2366104, 12.195, GO7032_LC|GO7084_LC
213809000, 289.5964355, -28.2127857, 13.063, GO7032_LC|GO7084_LC
213812150, 290.3846436, -28.2033653, 13.623, GO7032_LC|GO7084_LC
213819943, 290.4655151, -28.179987, 13.972, GO7032_LC|GO7084_LC
213828212, 290.9529114, -28.1550903, 12.965, GO7032_LC|GO7084_LC
213840079, 289.2970276, -28.1201153, 13.964, GO7032_LC|GO7084_LC
213853964, 290.3207397, -28.0783234, 13.01, GO7032_LC|GO7084_LC
213871864, 290.8161926, -28.0252476, 13.319, GO7032_LC|GO7084_LC
213879320, 289.6815796, -28.0035343, 13.765, GO7032_LC|GO7084_LC
213879379, 290.3473816, -28.0033646, 13.678, GO7032_LC|GO7084_LC
213894327, 289.9355774, -27.9593849, 13.969, GO7032_LC|GO7084_LC
213894951, 290.0823669, -27.9576416, 11.759, GO7032_LC|GO7084_LC
213896480, 290.0612183, -27.9531651, 12.533, GO7032_LC|GO7084_LC
213910667, 290.091095, -27.9116917, 13.063, GO7032_LC|GO7084_LC
213914312, 289.6376343, -27.9008846, 13.822, GO7032_LC|GO7084_LC
213926947, 290.2521667, -27.8635406, 13.091, GO7032_LC|GO7084_LC
213937603, 290.1140137, -27.8326054, 11.262, GO7032_LC|GO7084_LC
214374897, 283.117981, -26.6507702, 6.123, GO7075_LC|GO7084_LC
214707855, 281.2970581, -25.8328075, 12.915, GO7032_LC|GO7084_LC
214729243, 281.9568481, -25.7813969, 13.412, GO7032_LC|GO7084_LC
214790629, 282.2609253, -25.6369324, 12.933, GO7032_LC|GO7084_LC
214792277, 282.6671143, -25.6330223, 13.001, GO7032_LC|GO7084_LC
214794287, 281.4628906, -25.6282558, 13.398, GO7032_LC|GO7084_LC
214846854, 281.5706177, -25.5064507, 13.452, GO7032_LC|GO7084_LC
214919082, 281.5231323, -25.3404045, 12.621, GO7032_LC|GO7084_LC
214984995, 282.4205017, -25.1920395, 13.75, GO7032_LC|GO7084_LC
215011342, 281.5905457, -25.1338634, 13.882, GO7032_LC|GO7084_LC
215016531, 281.145813, -25.1226768, 10.174, GO7032_LC|GO7084_LC
215097604, 282.6282349, -24.9438019, 13.154, GO7032_LC|GO7084_LC
215116033, 281.2964783, -24.9038467, 13.68, GO7032_LC|GO7084_LC
215131252, 281.5396729, -24.8708038, 12.172, GO7032_LC|GO7084_LC
215147780, 281.1744385, -24.8348598, 11.847, GO7032_LC|GO7084_LC
215155802, 281.9384155, -24.8175163, 13.648, GO7032_LC|GO7084_LC
215213784, 282.0870667, -24.6929264, 13.531, GO7032_LC|GO7084_LC
215252993, 281.4429626, -24.6089535, 11.777, GO7032_LC|GO7084_LC
215260673, 282.1872559, -24.5926094, 13.642, GO7032_LC|GO7084_LC
215266868, 281.6070862, -24.5796375, 13.546, GO7032_LC|GO7084_LC
215337676, 282.4868774, -24.4296551, 13.445, GO7032_LC|GO7084_LC
215386288, 281.9700928, -24.3278198, 13.684, GO7032_LC|GO7084_LC
215745876, 290.2676392, -23.6195698, 7.375, GO7075_LC|GO7041_LC|GO7084_LC
215837631, 281.6463318, -23.4467449, 12.509, GO7013_LC|GO7030_LC|GO7084_LC|GO7022_LC|GO7042_LC
215976038, 287.1852112, -23.1902847, 6.449, GO7084_LC|GO7078_LC
216824878, 287.3074951, -21.6585178, 12.536, GO7086_LC|GO7084_LC|GO7085_LC
218297033, 293.0849609, -19.0573807, 11.181, GO7086_LC|GO7084_LC
219013697, 289.1450195, -17.7132072, 13.333, GO7035_LC|GO7084_LC
219150883, 288.7010498, -17.4147053, 12.69, GO7035_LC|GO7084_LC
219182144, 289.3823547, -17.3455887, 13.467, GO7035_LC|GO7084_LC
219198781, 288.8043518, -17.3083153, 13.94, GO7035_LC|GO7084_LC
219233227, 289.0053406, -17.2307796, 13.578, GO7035_LC|GO7084_LC
219234319, 289.0877991, -17.2282391, 13.692, GO7035_LC|GO7084_LC
219239645, 289.092041, -17.2162361, 13.85, GO7035_LC|GO7084_LC
219245901, 288.9877625, -17.2020779, 13.763, GO7035_LC|GO7084_LC
219265626, 288.4992065, -17.1570511, 12.758, GO7035_LC|GO7084_LC
219342005, 289.2334595, -16.9807453, 13.353, GO7035_LC|GO7084_LC
219347013, 288.9671631, -16.9690304, 13.619, GO7035_LC|GO7084_LC
219396051, 289.4607239, -16.8526192, 12.825, GO7035_LC|GO7084_LC
219408090, 288.8490295, -16.8237362, 12.956, GO7035_LC|GO7084_LC
219434492, 288.9075317, -16.7604389, 12.589, GO7035_LC|GO7084_LC
219508372, 288.8596802, -16.5775299, 12.883, GO7035_LC|GO7084_LC
219537754, 288.9630737, -16.5023632, 13.802, GO7035_LC|GO7084_LC
219538541, 288.7527466, -16.5003242, 13.677, GO7035_LC|GO7084_LC
219541572, 288.6213074, -16.4923515, 13.769, GO7035_LC|GO7084_LC
219574508, 288.6364441, -16.4064445, 13.082, GO7035_LC|GO7084_LC
219583965, 288.5749512, -16.3813477, 13.33, GO7035_LC|GO7084_LC
219595429, 289.629364, -16.3507462, 13.335, GO7035_LC|GO7084_LC
219609172, 288.5697327, -16.3139477, 13.501, GO7035_LC|GO7084_LC
219611545, 289.5912476, -16.3075981, 12.877, GO7035_LC|GO7084_LC
219645179, 288.5079956, -16.2171345, 13.531, GO7035_LC|GO7084_LC
219646006, 288.6552429, -16.2148514, 13.743, GO7035_LC|GO7084_LC
219664066, 288.6399841, -16.1655121, 13.529, GO7035_LC|GO7084_LC
219675415, 288.8985901, -16.1344109, 13.371, GO7035_LC|GO7084_LC
219675588, 288.6723022, -16.133934, 13.479, GO7035_LC|GO7084_LC
219703368, 288.902832, -16.0568047, 13.223, GO7035_LC|GO7084_LC
219708527, 289.4884338, -16.041748, 13.69, GO7035_LC|GO7084_LC
219709636, 288.8779602, -16.0384541, 13.249, GO7035_LC|GO7084_LC
219715530, 287.8713989, -16.0219002, 12.506, GO7035_LC|GO7084_LC
219718983, 288.6300354, -16.0122948, 12.791, GO7035_LC|GO7084_LC
219739630, 288.4187927, -15.9532557, 13.613, GO7035_LC|GO7084_LC
219763729, 289.3517456, -15.8825769, 13.862, GO7035_LC|GO7084_LC
219783202, 288.6627808, -15.8249559, 13.649, GO7035_LC|GO7084_LC