标题： 开普勒对一个L型矮星的监测 II. 具有多年寿命的云层 显示英文标题

标题： Kepler Monitoring of an L Dwarf II. Clouds with Multiyear Lifetimes

摘要： 我们展示了开普勒、斯皮策空间望远镜、盖亚-北、MMT和基特峰对L1矮星WISEP J190648.47+401106.8的观测数据。 我们发现，开普勒的光学光曲线在近两年的监测中相位和振幅一致，峰值到峰值振幅为1.4%。 斯皮策红外阵列相机3.6微米的观测与开普勒相位一致，光曲线形状和峰值到峰值振幅1.1%相似，但在4.5微米时，变异性振幅为$<$0.1%。 色球层H$\alpha$发射是可变的，但与稳定的开普勒光曲线不同步。 一个暗斑可以重现光曲线，但不是唯一的解决方案。 非均匀云层，特别是厚云覆盖区域，可以解释这个超冷矮星的多波长数据，不需要与异步磁发射变化耦合。 云的长期存在与在几小时和几天时间尺度上看到的较冷棕矮星的天气变化形成对比。 显示英文摘要

摘要： We present Kepler, Spitzer Space Telescope, Gemini-North, MMT, and Kitt Peak observations of the L1 dwarf WISEP J190648.47+401106.8. We find that the Kepler optical light curve is consistent in phase and amplitude over the nearly two years of monitoring with a peak-to-peak amplitude of 1.4%. Spitzer Infrared Array Camera 3.6 micron observations are in phase with Kepler with similar light curve shape and peak-to-peak amplitude 1.1%, but at 4.5 micron, the variability has amplitude $<$0.1%. Chromospheric H$\alpha$ emission is variable but not synced with the stable Kepler light curve. A single dark spot can reproduce the light curve but is not a unique solution. An inhomogeneous cloud deck, specifically a region of thick cloud cover, can explain the multi-wavelength data of this ultracool dwarf and need not be coupled with the asynchronous magnetic emission variations. The long life of the cloud is in contrast with weather changes seen in cooler brown dwarfs on the timescale of hours and days.