Zones, spots, and planetary-scale waves beating in brown dwarf atmospheres
Zones, spots, and planetary-scale waves beating in brown dwarf atmospheres
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褐矮星大气中的区域、斑点和行星尺度的波
DOI：
10.1126/science.aam9848
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发表时间：
2017
期刊：
影响因子：
56.9
通讯作者：
P. Lowrance
中科院分区：
文献类型：
--
作者：
D. Apai;T. Karalidi;M. Marley;Hao Yang;D. Flateau;D. Flateau;S. Metchev;S. Metchev;N. Cowan;N. Cowan;E. Buenzli;A. Burgasser;Jacqueline Radigan;É. Artigau;P. Lowrance
次恒星大气中的跳动带褐矮星是质量介于大行星和小恒星之间的天体。它们与气态巨行星有许多共同特征，特别是大气层的条件。阿派等人。分析了三颗褐矮星的红外亮度如何随时间变化。如果在大气层中旋转的云带产生节拍模式，则可以解释一些令人困惑的特征。这些波段可以在木星的光学图像中看到，但与海王星的红外图像最匹配。研究结果揭示了太阳和其他恒星周围的褐矮星和气态巨行星的大气物理学。科学，本期第 14 页。 683 对褐矮星的红外监测显示了其大气层内旋转的云带的证据。褐矮星是太阳系外巨行星的巨大类似物，可能拥有太阳系中未见的大气环流类型。我们分析了斯皮策太空望远镜对褐矮星的长期红外监测活动，以限制总共 192 次旋转的云层覆盖变化。红外亮度演化主要由行星尺度波对和少量亮点引起的拍频模式主导。拍动波具有相似的振幅，但由于速度或方向不同，表观周期略有不同。中温褐矮星的功率谱与海王星的功率谱相似，表明存在纬向温度和风速变化。我们的发现解释了棕矮星亮度变化中三种先前令人费解的行为。
Beating bands in substellar atmospheres Brown dwarfs are objects with masses that are between those of large planets and small stars. They share many features with gas giant planets, particularly conditions in their atmospheres. Apai et al. analyzed how the infrared brightness of three brown dwarfs changes over time. Several perplexing features can be explained if bands of clouds rotating within their atmospheres generate beat patterns. Such bands are seen in optical images of Jupiter but best match infrared images of Neptune. The results shed light on the atmospheric physics of brown dwarfs and gas giant planets around the Sun and other stars. Science, this issue p. 683 Infrared monitoring of brown dwarf stars shows evidence for bands of clouds rotating within their atmospheres. Brown dwarfs are massive analogs of extrasolar giant planets and may host types of atmospheric circulation not seen in the solar system. We analyzed a long-term Spitzer Space Telescope infrared monitoring campaign of brown dwarfs to constrain cloud cover variations over a total of 192 rotations. The infrared brightness evolution is dominated by beat patterns caused by planetary-scale wave pairs and by a small number of bright spots. The beating waves have similar amplitudes but slightly different apparent periods because of differing velocities or directions. The power spectrum of intermediate-temperature brown dwarfs resembles that of Neptune, indicating the presence of zonal temperature and wind speed variations. Our findings explain three previously puzzling behaviors seen in brown dwarf brightness variations.