Thermal inertia is a key information to quantify the physical status of a planetary surface; it can be retrieved by comparison between theoretical and observed temperature diurnal profiles. We have calculated the surface temperature for a set of locations on Ceres' surface with a thermophysical model that provides temperature as a function of thermal conductivity and roughness, and we have determined the values of those parameters for which the best fit with the observed data is obtained. The observed temperatures have been retrieved form spatially-resolved data from the Dawn mission. In our previous work [Rognini et al., 2019], we have found that the average thermal inertia for the overall surface of Ceres is low (from 1 to 15 to 60 ​J ​m⁻² ​s^−½ K⁻¹), as expected according to the general trend observed in the Solar System for atmosphere-less bodies, while the thermal inertia of the very bright faculae found in the floor of the Occator crater could not be well defined. Using more recently acquired VIR high resolution data we find that the central part of the Cerealia facula displays a thermal anomaly ($~10\text{K}$ above the average) compatible with a higher thermal inertia with respect to the surrounding regions, while the Vinalia facula does not display any consequently could have a grain size comparable with the Ceres’ surface average.

热惯性是量化行星表面物理状态的关键信息；它可以通过比较理论和观测到的温度日变化曲线来恢复。我们已经使用热物理模型计算了谷神星表面上一组位置的表面温度，该模型提供了作为热导率和粗糙度函数的温度，并且我们已经确定了与观测数据最匹配的那些参数的值获得。观测到的温度是从黎明号任务的空间分辨数据中提取的。在我们之前的工作 [ Rognini et al., 2019] 中，我们发现谷神星整个表面的平均热惯性很低（从 1 到 15 到 60 J m ^-2  s ^-½ K^-1 )，正如根据在太阳系中观察到的无大气天体的总体趋势所预期的那样，而在 Occator 陨石坑底部发现的非常明亮的光斑的热惯性无法明确定义。使用最近获得的 VIR 高分辨率数据，我们发现 Cerealia 光斑的中心部分显示出热异常（$~10\text{钾}$ 高于平均值）与相对于周围区域的更高热惯性兼容，而 Vinalia 光斑没有显示任何因此可能具有与谷神星表面平均值相当的粒度。