论文标题
彗星21p/giacobini-Zinner的光度法和高分辨率光谱法期间的2018年幻影
Photometry and high-resolution spectroscopy of comet 21P/Giacobini-Zinner during its 2018 apparition
论文作者
论文摘要
我们报告了化学奇特的木星家庭彗星（以下简称JFC）21p/giacobini-Zinner的光度法和高分辨率光谱。 21p彗星是碳链耗尽家族的著名成员，但也显示出胺的消耗。 We monitored continuously the comet over more than seven months with the two TRAPPIST telescopes (TN and TS), covering a large heliocentric distance range from 1.60 au inbound to 2.10 au outbound with a perihelion at 1.01 au on September 10, 2018. We computed and followed the evolution of the dust (represented by Af$ρ$) and gas production rates of the daughter species OH, NH, CN, c $ _3 $，c $ _2 $及其相对丰度oh，以及彗星轨道上的CN。我们将它们与以前的幻影中测得的那些进行了比较。该彗星的活动及其水生产率最多达到（3.72 $ \ pm $ 0.07）$ \ times $ 10 $^{28} $ molec/s 2018年8月17日（r $ _H $ = 1.07 au），前24天。在红色过滤器中，在同一日期（1646 $ \ pm $ 13）达到了A（0）F $ρ$的峰值。在近古前后，各种物种的丰度比在较大的地中心距离上非常恒定，显示了核表面冰的高均匀性。在过去的五个轨道中，彗星活动的行为和水平也非常相似。关于昏迷的灰尘颜色，21p显示出类似于JFC的反射梯度。我们在围栏后一周在ESO VLT处获得了21p的高分辨率光谱。使用CN B-X（0,0）紫罗兰带，我们测量了$^{12} $ c/$ c/$^{13} $ c和$^{14} $ n/$ n/$^{15} $ n同位素比为100 $ \ pm $ \ pm $ 10和145 $ \ pm $ 10，分别与通常与Comets相符的非常均匀。
We report on photometry and high resolution spectroscopy of the chemically peculiar Jupiter-family Comet (hereafter JFC) 21P/Giacobini-Zinner. Comet 21P is a well known member of the carbon-chain depleted family but displays also a depletion of amines. We monitored continuously the comet over more than seven months with the two TRAPPIST telescopes (TN and TS), covering a large heliocentric distance range from 1.60 au inbound to 2.10 au outbound with a perihelion at 1.01 au on September 10, 2018. We computed and followed the evolution of the dust (represented by Af$ρ$) and gas production rates of the daughter species OH, NH, CN, C$_3$, and C$_2$ and their relative abundances to OH and to CN over the comet orbit. We compared them to those measured in the previous apparitions. The activity of the comet and its water production rate reached a maximum of (3.72$\pm$0.07)$\times$10$^{28}$ molec/s on August 17, 2018 (r$_h$=1.07 au), 24 days before perihelion. The peak value of A(0)f$ρ$ was reached on the same date (1646$\pm$13) cm in the red filter. The abundance ratios of the various species are remarkably constant over a large range of heliocentric distances, before and after perihelion, showing a high level of homogeneity of the ices in the surface of the nucleus. The behaviour and level of the activity of the comet is also remarkably similar over the last five orbits. About the coma dust colour, 21P shows reflectively gradients similar to JFCs. We obtained a high resolution spectrum of 21P with UVES at ESO VLT one week after perihelion. Using the CN B-X (0,0) violet band, we measured $^{12}$C/$^{13}$C and $^{14}$N/$^{15}$N isotopic ratios of 100$\pm$10 and 145$\pm$10, respectively, both in very good agreement with what is usually found in comets.
