令人困惑的小行星21 Lutetia：我们在罗塞塔飞越之前的知识
Puzzling asteroid 21 Lutetia: our knowledge prior to the Rosetta fly-by
摘要：
2004-2009年开展了广泛的观测活动，目的是在2010年7月罗塞塔号飞越之前完成对卢泰西亚的地面调查。我们已经获得了BVRI光度和V波段偏振测量在很宽的相位角范围内，可见光和红外光谱在0.4-2.4微米范围内。我们分析了他们与以前公布的数据一起检索信息Lutetia的表面特性。测定了Lutetia表面在极面附近的光变曲线振幅、绝对星等、相对效应、相位系数和BVRI颜色。我们更精确地定义了偏振相位曲线的参数，并显示了它们与其他中等偏高小行星的明显差异。为了解释不同技术发现的特征，我们提出：（一）Lutetia具有非凸形形状，可能是由于存在一个大的陨石坑，以及可能与表面形态有关的不均匀表面特性;（ii）至少部分表面被粒度小于20微米的细粒风化层覆盖;（三）与Lutetia的表面成分最接近的陨石类似物是特殊类型的碳质陨石，或者Lutetia具有不具有代表性的特定表面成分在研究的陨石中。
英文摘要：
A wide observational campaign was carried out in 2004-2009 aimed to complete the ground-based investigation of Lutetia prior to the Rosetta fly-by in July 2010. We have obtained BVRI photometric and V-band polarimetric measurements over a wide range of phase angles, and visible and infrared spectra in the 0.4-2.4 micron range. We analyzed them together with previously published data to retrieve information on Lutetia's surface properties. Values of lightcurve amplitudes, absolute magnitude, opposition effect, phase coefficient and BVRI colors of Lutetia surface seen at near pole-on aspect have been determined. We defined more precisely parameters of polarization phase curve and showed their distinct deviation from any other moderate-albedo asteroid. An indication of possible variations both in polarization and spectral data across the asteroid surface was found. To explain features found by different techniques we propose that (i) Lutetia has a non-convex shape, probably due to the presence of a large crater, and heterogeneous surface properties probably related to surface morphology; (ii) at least part of the surface is covered by a fine-grained regolith with particle size less than 20 microns; (iii) the closest meteorite analogues of Lutetia's surface composition are particular types of carbonaceous chondrites or Lutetia has specific surface composition not representative among studied meteorites.
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。
