title: NEPTUNE'S DYNAMIC ATMOSPHERE FROMKEPLER K2OBSERVATIONS: IMPLICATIONS FOR BROWN DWARF LIGHT CURVE ANALYSES.
abstract: Observations of Neptune with theKeplerSpace Telescope yield a 49 day light curve with 98% coverage at a 1 minute cadence. A significant signature in the light curve comes from discrete cloud features. We compare results extracted from the light curve data with contemporaneous disk-resolved imaging of Neptune from the Keck 10-m telescope at 1.65 microns andHubble Space Telescopevisible imaging acquired nine months later. This direct comparison validates the feature latitudes assigned to theK2light curve periods based on Neptune's zonal wind profile, and confirms observed cloud feature variability. Although Neptune's clouds vary in location and intensity on short and long timescales, a single large discrete storm seen in Keck imaging dominates theK2and Hubble light curves; smaller or fainter clouds likely contribute to short-term brightness variability. TheK2Neptune light curve, in conjunction with our imaging data, provides context for the interpretation of current and future brown dwarf and extrasolar planet variability measurements. In particular we suggest that the balance between large, relatively stable, atmospheric features and smaller, more transient, clouds controls the character of substellar atmospheric variability. Atmospheres dominated by a few large spots may show inherently greater light curve stability than those which exhibit a greater number of smaller features.
authors.affiliation: NASA Goddard Space Flight Center, Solar System Exploration Division (690.0), 8800 Greenbelt Road, Greenbelt, MD 20771, USA.
authors.forename: Amy A
authors.initials: AA
authors.lastname: Simon
authors.affiliation: Université de Montréal, Département de Physique, 2900 Boul. Édouard-Montpetit, Montréal, QC, H3T 1J4, Canada.
authors.forename: Jason F
authors.initials: JF
authors.lastname: Rowe
authors.affiliation: New Mexico State University, Department of Astronomy, P.O. Box 30001, Las Cruces, NM 88003-4500, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Gaulme
authors.affiliation: AURA, Inc., 1212 New York Avenue NW, Washington, DC 20005, USA.
authors.forename: Heidi B
authors.initials: HB
authors.lastname: Hammel
authors.affiliation: University of Leicester, Department of Physics and Astronomy, University Road, Leicester, LE1 7RH, UK.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Casewell
authors.affiliation: University of California, Santa Cruz, Department of Astronomy & Astrophysics, 1156 High Street, 275 Interdisciplinary Sciences Building, Santa Cruz, CA 95064, USA.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Fortney
authors.affiliation: University of Delaware, Department of Physics and Astronomy, 104 The Green, Newark, DE 19716, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Gizis
authors.affiliation: NASA Ames Research Center, Space Sciences & Astrobiology Division, MS 245-3, Moffett Field, CA 94035, USA.
authors.forename: Jack J
authors.initials: JJ
authors.lastname: Lissauer
authors.affiliation: New Mexico Institute of Mining and Technology, Physics Department, Workman Center 345, 801 Leroy Place, Socorro, NM 87801, USA.
authors.forename: Raul
authors.initials: R
authors.lastname: Morales-Juberias
authors.affiliation: Jet Propulsion Laboratory/California Institute of Technology, M/S 183-501, 4800 Oak Grove Drive, Pasadena, CA 91109, USA.
authors.forename: Glenn S
authors.initials: GS
authors.lastname: Orton
authors.affiliation: University of California at Berkeley, Astronomy Department, Berkeley, CA 947200-3411, USA.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Wong
authors.affiliation: NASA Ames Research Center, Space Sciences & Astrobiology Division, MS 245-3, Moffett Field, CA 94035, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Marley
keywords: brown dwarfs; planets and satellites: atmospheres; planets and satellites: gaseous planets; stars: oscillations (including pulsations); stars: rotation; starspots