Atmospheric Structure of Neptune in 1994, 1995, and 1996
Atmospheric Structure of Neptune in 1994, 1995, and 1996
复制标题
1994年、1995年和1996年海王星的大气结构
DOI：
10.1006/icar.1997.5764
复制
发表时间：
1997
期刊：
影响因子：
3.2
通讯作者：
G. Lockwood
中科院分区：
文献类型：
--
作者：
H. Hammel;G. Lockwood
摘要 1994年、1995年和1996年哈勃太空望远镜对海王星的成像揭示了大气特征的变化。 1994 年和 1995 年，纬度 +31° 附近 467 nm 处的黑点均出现，但 1996 年 3 月的图像中没有出现。然而，1996 年 8 月的更大数据集（Sromovsky 等人，Bull. Am. Astron. Soc. 28, 1077, 1996）揭示了一个黑点。这些特征的大小、形状和对比度与 1989 年航海家号遭遇时出现的大黑斑相似。黑斑出现在当时地球上可见的单个最亮的 619 纳米和 889 纳米特征附近。 1994 年，北半球的甲烷带云比周围大气亮 6 倍，但 1995 年和 1996 年仅亮 2 倍。海王星上的纬向带图案在 1994 年至 1996 年期间保持稳定，但与 1989 年旅行者号观测到的情况不同，当时来自行星纬度 -40° 至 -68° 的显着暗带在蓝色区域占主导地位波长。 1994-1996年，这条带较弱，仅从-55°延伸到-70°，这或许可以解释1989年至1994年间海王星0.06星等的增亮。明亮的甲烷云通常出现在特定纬度，但活跃纬度从1989年的-25°变化到1994年的-30°和-46°。+30°附近的区域在这两个地区都很活跃。 1989年和 1994-1996。我们确认了航行者号测量的纬向风廓线的总体形状和稳定性，用更准确的值修改了之前的测量结果，并填充了以前没有看到云的纬度+38°、-30°和-31°。
Abstract Hubble Space Telescope imaging of Neptune in 1994, 1995, and 1996 reveals changes in atmospheric features. Dark spots at 467 nm near latitude +31° were present in both 1994 and 1995, but absent from images in March 1996. However, a larger data set in August 1996 (Sromovsky et al., Bull. Am. Astron. Soc. 28, 1077, 1996) revealed a dark spot. The features resemble the Great Dark Spot present during the Voyager encounter in 1989 in size, shape, and contrast. Dark spots occur near the single brightest 619- and 889-nm features visible on the planet at that time. Methane-band clouds in the northern hemisphere were a factor of 6 brighter than the surrounding atmosphere in 1994, but only a factor of 2 brighter in 1995 and 1996. The pattern of zonal bands on Neptune was stable from 1994 to 1996, but differed from that seen by Voyager in 1989 when a prominent dark band from planetographic latitudes −40° to −68° dominated at blue wavelengths. In 1994–1996, this band was weaker and extended only from −55° to −70°, perhaps explaining the 0.06-mag brightening of Neptune between 1989 and 1994. Bright methane clouds generally appear at specific latitudes, but the active latitudes change from −25° in 1989 to −30° and −46° in 1994. The region near +30° was active in both 1989 and 1994–1996. We confirm the general shape and stability of the zonal wind profile measured by Voyager, revising previous measurements with more accurate values and filling in latitudes +38°, −30°, and −31° where no clouds had previously been seen.