Combi M R, Mäkinen T T, Bertaux J-L, Quémerais E, Ferron S
Dept. of Climate and Space Sciences and Engineering University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143.
Finnish Meteorological Institute, Box 503 SF-00101 Helsinki, FINLAND.
Icarus. 2019 Jan 1;317:610-620. doi: 10.1016/j.icarus.2018.08.031. Epub 2018 Sep 3.
The Solar Wind Anisotropies (SWAN) instrument on the SOlar and Heliospheric Observatory (SOHO) satellite has observed 44 long period and new Oort cloud comets and 36 apparitions of 17 short period comets since its launch in December 1995. Water production rates have been determined from the over 3700 images producing a consistent set of activity variations over large parts of each comet's orbit. This has enabled the calculation of exponential power-law variations with heliocentric distance of these comets both before and after perihelion, as well as the absolute values of the water production rates. These various measures of overall water activity including pre- and post-perihelion exponents, absolute water production rates at 1 AU, active surface areas and their variations have been compared with a number of dynamical quantities for each comet including dynamical class, original semi-major axis, nucleus radius (when available), and compositional taxonomic class. Evidence for evolution of cometary nuclei is seen in both long-period and short-period comets.
自1995年12月发射以来，太阳和日球层天文台（SOHO）卫星上的太阳风各向异性（SWAN）仪器观测到了44颗长周期和新奥尔特云彗星以及17颗短周期彗星的36次出现。通过对3700多张图像的分析确定了水的产生率，从而在每颗彗星轨道的大部分区域得出了一组一致的活动变化情况。这使得能够计算出这些彗星在近日点前后水产生率随日心距离的指数幂律变化，以及水产生率的绝对值。已将包括近日点前后指数、1天文单位处的绝对水产生率、活跃表面积及其变化在内的各种总体水活动量度，与每颗彗星的一些动力学量进行了比较，这些动力学量包括动力学类别、原始半长轴、核半径（如有）和成分分类类别。在长周期和短周期彗星中均可见到彗核演化的证据。
