Coma morphology and dust emission pattern of comet C/2020 F3 (NEOWISE)
Coma morphology and dust emission pattern of comet C/2020 F3 (NEOWISE)
复制标题
C/2020 F3彗星的彗发形态和尘埃发射模式（NEOWISE）
DOI：
10.1093/mnras/stab1849
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
G. Fardelli
中科院分区：
文献类型：
--
作者：
F. Manzini;V. Oldani;P. Ochner;E. Barbotin;L. Bedin;R. Behrend;G. Fardelli
最近彗星 C/2020 F3 (NEOWISE) 的近距离接近使我们能够研究其内部彗发的形态。根据对围绕核膨胀的螺旋结构上的尘埃喷射速度的测量，我们估计了平均反投影膨胀速度 Vd = 1.11±0.08 km s−1。假设彗星每次自转后都会形成一个新的壳层，则得出自转周期为7.8±0.2小时。自旋轴方向估计为 RA 210°±10°，Dec. +35°±10°。彗发形态似乎与位于原子核中纬度地区的两个强烈的、截然相反的发射有关。慧发的定性建模对于各种灰尘尺寸（0.80 至 800μm）和反相关密度（0.003 至 3.0 g cm−3）产生了一致的结果。使用 V j 和 r-Sloan 滤光片拍摄的图像显示，前两个壳中的灰尘浓度较高，并且从第三个壳向外的 B 和 V 带通中发射的自由基密度不断增加。尾部的条纹状结构表明灰尘颗粒具有不同的尺寸。
The recent close approach of comet C/2020 F3 (NEOWISE) allowed us to study the morphology of its inner coma. From the measurement of the dust ejection velocity on spiral structures expanding around the nucleus, we estimated a mean deprojected expansion velocity Vd = 1.11±0.08 km s−1. Assuming that a new shell formed after every rotation of the comet, a rotation period of 7.8±0.2 hours was derived. The spin axis orientation was estimated at RA 210◦±10◦, Dec. +35◦ ± 10◦. The coma morphology appears related to two strong, diametrically opposite emissions located at mid-latitudes on the nucleus. A qualitative modelling of the coma produced consistent results with a wide range of dust sizes (0.80 to 800μm), with inversely correlated densities (0.003 to 3.0 g cm−3). Images taken with V j and r-Sloan filters showed a greater concentration of dust in the first two shells, and an increasing density of radicals emitting in the B and V band-passes from the third shell outwards. Striaelike structures in the tail suggest that dust particles have different sizes.