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arXiv 1903.04764astro-ph.EP
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潜在危险小行星2014 JO25的时间和相位分辨光谱

Time and phase resolved optical spectra of potentially hazardous asteroid 2014 JO25

Kumar Venkataramani, Shashikiran Ganesh, Archita Rai, Marek Husárik, K. S. Baliyan, U. C. Joshi

摘要:

小行星2014 JO 25被小行星中心认为是“潜在危险”,在2017年4月19日和20日的近地球遭遇期间进行了光谱跟踪。该小行星的光谱是用安装在印度阿布山红外观测站1.2米望远镜上的低分辨率摄谱仪拍摄的。这颗小行星来自靠近匈牙利小行星群的区域,其轨道类似彗星,具有相对较高的倾角和较大的离心率。因此,我们对这颗小行星进行了光学光谱观测,以寻找类似彗星的分子发射或爆发。然而,这颗小行星显示出一个没有特征的光谱,没有任何彗星般的特征。利用从光谱中得出的V波段星等分析了小行星的光变曲线,并得出了小行星自转的最可能解。采用IAU认可的标准双参数H-G模型,在V波段测定了小行星的绝对星等$H$和斜率参数$G$。一个特殊的,很少发现的结果,从这些观察是其相位发蓝的趋势。相对B-V颜色指数似乎随着相位角的增加而减小,这表明相位蓝化趋势。这种趋势在文献中很少报道。然而,相位红化在小行星中非常常见。通过对观测数据拟合Hapke相函数,估算了小行星的不对称参数$g$和单次散射散射参数$w$。该小行星显示出相对较大的单次散射散射率值和高度后向散射的表面。

英文摘要:

The asteroid 2014 JO25, considered to be "potentially hazardous" by the Minor Planet Center, was spectroscopically followed during its close-Earth encounter on 19th and 20th of April 2017. The spectra of the asteroid were taken with the low resolution spectrograph (LISA), mounted on the 1.2-m telescope at the Mount Abu Infrared Observatory, India. Coming from a region close to the Hungaria population of asteroids, this asteroid follows a comet-like orbit with a relatively high inclination and large eccentricity. Hence, we carried out optical spectroscopic observations of the asteroid to look for comet-like molecular emissions or outbursts. However, the asteroid showed a featureless spectrum, devoid of any comet-like features. The asteroid's light curve was analyzed using V band magnitudes derived from the spectra and the most likely solution for the rotation of the asteroid was obtained. The absolute magnitude $H$ and the slope parameter $G$ were determined for the asteroid in V filter band using the IAU accepted standard two parameter H-G model. A peculiar, rarely found result from these observations is its phase bluing trend. The relative B-V color index seems to decrease with increasing phase angle, which indicates a phase bluing trend. Such trends have seldom been reported in literature. However, phase reddening in asteroids is very common. The asymmetry parameter $g$ and the single scattering albedo $w$ were estimated for the asteroid by fitting the Hapke phase function to the observed data. The asteroid shows relatively large value for the single scattering albedo and a highly back scattering surface.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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