Infrared observations of an outburst of small dust grains from the nucleus of Comet P/Halley 1986 III at perihelion
Infrared observations of an outburst of small dust grains from the nucleus of Comet P/Halley 1986 III at perihelion
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对 P/Halley 1986 III 彗星近日点彗核小尘埃颗粒爆发的红外观测
DOI：
10.1006/icar.1995.1011
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发表时间：
1995
期刊：
影响因子：
3.2
通讯作者：
T. Hayward
中科院分区：
文献类型：
--
作者：
R. Gehrz;C. H. Johnson;S. D. Magnuson;E. Ney;T. Hayward
对Gehrz和Ney（1992，Icarus 100，162-186）获得的0.7- 23 μm红外数据库的仔细检查表明，P/Halley 1986 III彗星的彗核在1986年2月9.46 UT经过近日点的几个小时内，在3天的时间内发出了一次小尘埃颗粒的爆发。这次爆发的特征是彗发的颗粒色温T obs、温度过剩（T：S = T obs / T BB）、红外光度、辐射强度和10 μm硅酸盐发射特征强度显著增加。这些变化都与半径约为0.5 μm的颗粒云突然从核中喷出相一致。这次爆发可能产生了一些尘埃，这些尘埃是1986年2月22日UT拍摄的一些尾部流光的原因。尘埃爆发的高峰发生在先驱者金星轨道器紫外线分光仪测量的水生产率明显增加之前约3天。我们认为，喷射，释放大量的小颗粒可能是主要负责的一些变量的红外行为，已报告的P/哈雷彗星和其他彗星在过去的二十年。这种喷流也可能解释了IR I型和IR II型彗星之间的一些差异。
Abstract A close examination of the 0.7- to 23-μm infrared data base acquired by Gehrz and Ney (1992, Icarus 100, 162-186) suggests that the nucleus of Comet P/Halley 1986 III emitted a burst of small dust grains during a 3-day period commencing within hours of perihelion passage on 1986 February 9.46 UT. The outburst was characterized by significant increases in the coma's grain color temperature T obs , temperature excess (superheat: S = T obs / T BB ), infrared luminosity, albedo, and 10-μm silicate emission feature strength. These changes are all consistent with the sudden ejection from the nucleus of a cloud of grains with radii of approximately 0.5 μm. This outburst may have produced the dust that was responsible for some of the tail streamers photographed on 1986 February 22 UT. The peak of the dust outburst occurred about 3 days before a pronounced increase in the water production rate measured by the Pioneer Venus Orbiter Ultraviolet Spectrometer. We suggest that jets that release large quantities of small particles may be largely responsible for some of the variable infrared behavior that has been reported for P/Halley and other comets during the past two decades. Such jets may also account for some of the differences between IR Type I and IR Type II comets.