# Summary of K2 Program GO8034 Title: Observing Uranus With Kepler PI: Rowe, Jason Frank (SETI Institute) CoIs: Lissauer, Jack J.; Gizis, John E.; Gaulme, Patrick; Fletcher, Leigh N; Casewell, Sarah L; Simon, Amy A; Marley, Mark S; Hammel, Heidi B Science Goals Objectives: There are two classes of solar system giant planets: the gas giants and the ice giants. Uranus and Neptune, with masses less than 18 Earth masses comprise a distinct class from Jupiter and Saturn, with masses greater than 95 Earth masses. The primary constituents of Uranus and Neptune are likely ices surrounding a rocky core with a relatively thin atmospheric veneer of hydrogen rich gas. The Kepler Mission has ably demonstrated that such Neptune and Uranus sized planets are commonmuch more common than gas giants in factoutside of the solar system. It is thus important to understand the interior structure of these worlds in order to better model their formation and evolution. Unfortunately our best data on the interior structure of these worlds comes from the gravitational harmonics measured during the single flybys of Voyager 2 about 25 years ago. Oscillations not only provide complimentary information but would be more sensitive to internal sharp boundaries. The two wheel K2 mission will now observe fields along the ecliptic continuously up to 80 days. K2 presents an opportunity to obtain ultra-high precision, high duty-cycle, integrated disc photometry of the Solar Systems ice giants to search for oscillations. Seismology is by far the most promising technique for constraining the core mass of a giant planet, independent of the uncertainties that plague interior model inversion. Additional goals include long term (80 day) monitoring of weather and rotation modulation. Record of ground and based photometry have shown that rotational variability on ice giants can come from rather unexpected sources. We plan to have a limited set disk-resolved images to help correlate observations from K2 with atmospheric activity. K2 observations of Neptune have already shown clear 2% variations on time-scales related to the rotation period. Methodology: Oscillations of a giant planet change the size of the observable disk, thus altering the total reflected solar flux. From simple geometry alone a velocity of 50 cm/s with a frequency of 1 mHz changes the reflected flux at the several ppm level. Thus photometry has the potential to detect oscillations excited by turbulence from convection that pumps energy into random sound waves. Uranus brightness at quadrature is comparable to that of the brightest stars that Kepler has monitored in its exoplanet search with an apparent size ranging from 3.3 to 4.0. It has been repeatedly shown that Kepler photometry for bright (V<8) stars can reach noise levels of better than 1 ppm in the Fourier domain on time-scales shorter than 30 minutes with a month of observations. There have been a number of searches for giant planet oscillations, primarily for Jupiter. Gaulme et al. (2011) reported the Doppler detection of jovian modes with peak amplitudes near frequencies of 1.2 mhz, a period of about 14 minutes. One of us (MM) carried out an exploratory computation of ice giant mode frequencies some years ago but did not publish the results, but as with Jupiter and Saturn expected periods are in the range of tens to hundreds of minutes. Thus short-cadence is necessary. Summary: Observations of Uranus (and other giant planets) with Kepler have the potential to answer many long-standing questions regarding the interior structure of ice giants from detecting a core to understanding the compositional structure of the envelope. The clear detection of oscillation modes will of course energize a new generation of theorists to compute model frequencies for comparison with data. We propose that K2 observe Uranus continuously with short and long-cadence photometry. # Targets requested by this program that have been observed (254) EPIC ID, RA (J2000) [deg], Dec (J2000) [deg], magnitude, Investigation IDs 200068402, , , , GO8034_LC 200068403, , , , GO8034_LC 200068404, , , , GO8034_LC 200068405, , , , GO8034_LC 200068406, , , , GO8034_LC 200068407, , , , GO8034_LC 200068408, , , , GO8034_LC 200068409, , , , GO8034_LC 200068410, , , , GO8034_LC 200068411, , , , GO8034_LC 200068412, , , , GO8034_LC 200068413, , , , GO8034_LC 200068414, , , , GO8034_LC 200068415, , , , GO8034_LC 200068416, , , , GO8034_LC 200068417, , , , GO8034_LC 200068418, , , , GO8034_LC 200068419, , , , GO8034_LC 200068420, , , , GO8034_LC 200068421, , , , GO8034_LC 200068422, , , , GO8034_LC 200068423, , , , GO8034_LC 200068424, , , , GO8034_LC 200068425, , , , GO8034_LC 200068426, , , , GO8034_LC 200068427, , , , GO8034_LC 200068428, , , , GO8034_LC 200068429, , , , GO8034_LC 200068430, , , , GO8034_LC 200068431, , , , GO8034_LC 200068432, , , , GO8034_LC 200068433, , , , GO8034_LC 200068434, , , , GO8034_LC 200068435, , , , GO8034_LC 200068436, , , , GO8034_LC 200068437, , , , GO8034_LC 200068438, , , , GO8034_LC 200068439, , , , GO8034_LC 200068440, , , , GO8034_LC 200068441, , , , GO8034_LC 200068442, , , , GO8034_LC 200068443, , , , GO8034_LC 200068444, , , , GO8034_LC 200068445, , , , GO8034_LC 200068446, , , , GO8034_LC 200068447, , , , GO8034_LC 200068448, , , , GO8034_LC 200068449, , , , GO8034_LC 200068450, , , , GO8034_LC 200068451, , , , GO8034_LC 200068452, , , , GO8034_LC 200068453, , , , GO8034_LC 200068454, , , , GO8034_LC 200068455, , , , GO8034_LC 200068456, , , , GO8034_LC 200068457, , , , GO8034_LC 200068458, , , , GO8034_LC 200068459, , , , GO8034_LC 200068460, , , , GO8034_LC 200068461, , , , GO8034_LC 200068462, , , , GO8034_LC 200068463, , , , GO8034_LC 200068464, , , , GO8034_LC 200068465, , , , GO8034_LC 200068466, , , , GO8034_LC 200068467, , , , GO8034_LC 200068468, , , , GO8034_LC 200068469, , , , GO8034_LC 200068470, , , , GO8034_LC 200068471, , , , GO8034_LC 200068472, , , , GO8034_LC 200068473, , , , GO8034_LC 200068474, , , , GO8034_LC 200068475, , , , GO8034_LC 200068476, , , , GO8034_LC 200068477, , , , GO8034_LC 200068478, , , , GO8034_LC 200068479, , , , GO8034_LC 200068480, , , , GO8034_LC 200068481, , , , GO8034_LC 200068482, , , , GO8034_LC 200068483, , , , GO8034_LC 200068484, , , , GO8034_LC 200068485, , , , GO8034_LC 200068486, , , , GO8034_LC 200068487, , , , GO8034_LC 200068488, , , , GO8034_LC 200068489, , , , GO8034_LC 200068490, , , , GO8034_LC 200068491, , , , GO8034_LC 200068492, , , , GO8034_LC 200068493, , , , GO8034_LC 200068494, , , , GO8034_LC 200068495, , , , GO8034_LC 200068496, , , , GO8034_LC 200068497, , , , GO8034_LC 200068498, , , , GO8034_LC 200068499, , , , GO8034_LC 200068500, , , , GO8034_LC 200068501, , , , GO8034_LC 200068502, , , , GO8034_LC 200068503, , , , GO8034_LC 200068504, , , , GO8034_LC 200068505, , , , GO8034_LC 200068506, , , , GO8034_LC 200068507, , , , GO8034_LC 200068508, , , , GO8034_LC 200068509, , , , GO8034_LC 200068510, , , , GO8034_LC 200068511, , , , GO8034_LC 200068512, , , , GO8034_LC 200068513, , , , GO8034_LC 200068514, , , , GO8034_LC 200068515, , , , GO8034_LC 200068516, , , , GO8034_LC 200068517, , , , GO8034_LC 200068518, , , , GO8034_LC 200068519, , , , GO8034_LC 200068520, , , , GO8034_LC 200068521, , , , GO8034_LC 200068522, , , , GO8034_LC 200068523, , , , GO8034_LC 200068524, , , , GO8034_LC 200068525, , , , GO8034_LC 200068526, , , , GO8034_LC 200068527, , , , GO8034_LC 200068528, , , , GO8034_LC 200068529, , , , GO8034_LC 200068530, , , , GO8034_LC 200068531, , , , GO8034_LC 200068532, , , , GO8034_LC 200068533, , , , GO8034_LC 200068534, , , , GO8034_LC 200068535, , , , GO8034_LC 200068536, , , , GO8034_LC 200068537, , , , GO8034_LC 200068538, , , , GO8034_LC 200068539, , , , GO8034_LC 200068540, , , , GO8034_LC 200068541, , , , GO8034_LC 200068542, , , , GO8034_LC 200068543, , , , GO8034_LC 200068544, , , , GO8034_LC 200068545, , , , GO8034_LC 200068546, , , , GO8034_LC 200068547, , , , GO8034_LC 200068548, , , , GO8034_LC 200068549, , , , GO8034_LC 200068550, , , , GO8034_LC 200068551, , , , GO8034_LC 200068552, , , , GO8034_LC 200068553, , , , GO8034_LC 200068554, , , , GO8034_LC 200068555, , , , GO8034_LC 200068556, , , , GO8034_LC 200068557, , , , GO8034_LC 200068558, , , , GO8034_LC 200068559, , , , GO8034_LC 200068560, , , , GO8034_LC 200068561, , , , GO8034_LC 200068562, , , , GO8034_LC 200068563, , , , GO8034_LC 200068564, , , , GO8034_LC 200068565, , , , GO8034_LC 200068566, , , , GO8034_LC 200068567, , , , GO8034_LC 200068568, , , , GO8034_LC 200068569, , , , GO8034_LC 200068570, , , , GO8034_LC 200068571, , , , GO8034_LC 200068572, , , , GO8034_LC 200068573, , , , GO8034_LC 200068574, , , , GO8034_LC 200068575, , , , GO8034_LC 200068576, , , , GO8034_LC 200068577, , , , GO8034_LC 200068578, , , , GO8034_LC 200068579, , , , GO8034_LC 200068580, , , , GO8034_LC 200068581, , , , GO8034_LC 200068582, , , , GO8034_LC 200068583, , , , GO8034_LC 200068584, , , , GO8034_LC 200068585, , , , GO8034_LC 200068586, , , , GO8034_LC 200068587, , , , GO8034_LC 200068588, , , , GO8034_LC 200068589, , , , GO8034_LC 200068590, , , , GO8034_LC 200068591, , , , GO8034_LC 200068592, , , , GO8034_LC 200068593, , , , GO8034_LC 200068594, , , , GO8034_LC 200068595, , , , GO8034_LC 200068596, , , , GO8034_LC 200068597, , , , GO8034_LC 200068598, , , , GO8034_LC 200068599, , , , GO8034_LC 200068600, , , , GO8034_LC 200068601, , , , GO8034_LC 200068602, , , , GO8034_LC 200068603, , , , GO8034_LC 200068604, , , , GO8034_LC 200068605, , , , GO8034_LC 200068606, , , , GO8034_LC 200068607, , , , GO8034_LC 200068608, , , , GO8034_LC 200068609, , , , GO8034_LC 200068610, , , , GO8034_LC 200068611, , , , GO8034_LC 200068612, , , , GO8034_LC 200068613, , , , GO8034_LC 200068614, , , , GO8034_LC 200068615, , , , GO8034_LC 200068616, , , , GO8034_LC 200068617, , , , GO8034_LC 200068618, , , , GO8034_LC 200068619, , , , GO8034_LC 200068620, , , , GO8034_LC 200068621, , , , GO8034_LC 200068622, , , , GO8034_LC 200068623, , , , GO8034_LC 200068624, , , , GO8034_LC 200068625, , , , GO8034_LC 200068626, , , , GO8034_LC 200068627, , , , GO8034_LC 200068628, , , , GO8034_LC 200068629, , , , GO8034_LC 200068630, , , , GO8034_LC 200068631, , , , GO8034_LC 200068632, , , , GO8034_LC 200068633, , , , GO8034_LC 200068634, , , , GO8034_LC 200068635, , , , GO8034_LC 200068636, , , , GO8034_LC 200068637, , , , GO8034_LC 200068638, , , , GO8034_LC 200068639, , , , GO8034_LC 200068640, , , , GO8034_LC 200068641, , , , GO8034_LC 200068642, , , , GO8034_LC 200068643, , , , GO8034_LC 200068644, , , , GO8034_LC 200068645, , , , GO8034_LC 200068646, , , , GO8034_LC 200068647, , , , GO8034_SC 200068648, , , , GO8034_SC 200068649, , , , GO8034_SC 200068650, , , , GO8034_SC 200068651, , , , GO8034_SC 200068652, , , , GO8034_SC 200068653, , , , GO8034_SC 200068654, , , , GO8034_SC 200068655, , , , GO8034_SC