Determining the sizes of selected asteroids with different techniques

• DOI: 10.5194/epsc2024-597
• Publication Date: 2024-07-03T11:09:04Z
• Authors: Antoine Choukroun; Anna Marciniak; Josef Ďurech

Introduction:Determining the physical parameters of asteroids is a complex yet crucialtask in planetary science. Recent advancements in observational techniques andthe availability of vast data have led to the development of numerous analyticaland modelling approaches for parameter determination.In our research, we focused on studying several main-belt asteroids usinghigh-quality data. Initially, we modelled visible lightcurves using convex inver-sion (see [1] and [2]) obtaining precise information on the spin axis and an initialshape model. Subsequently, we used these results as input for another mod-elling technique called Convex Inversion Thermophysical Model (CITPM, see[3]). CITPM optimizes the model based both on lightcurves and thermal data,providing output such as surface roughness, temperature distribution, thermalinertia, and asteroid size. Additionally, by fitting the initial models to stellaroccultation observations, we determined asteroid sizes with another recognizedprecise method. This revealed a good agreement with the sizes determined byCITPM, enhancing the credibility of its other output parameters.Results: As an example, we present here the results for one target: slowly rotatingasteroid (527) Euryanthe. The CITPM model for solution 1 and solution 2 areshown in Figure 1. Due to the mirror-pole ambiguity, we obtain two possiblesolutions (see [4]). Some of the parameters derived using the CITPM are givenin Table 1. Additionally, Figure 2 shows a fit of our models of (527) Euryantheto a stellar occultation by this asteroid observed on 2019-01-20. The best fit wasobtained for pole solution 2, and the corresponding size was found at 52.7 ± 1.8km. Conclusions:The utilization of quality data has enabled the generation of reliable asteroidmodels. Furthermore, the supplementary use of the occultation observationtechnique, renowned for its accuracy in determining asteroid sizes, has provento be consistent with sizes determined via the CITPM technique. Without suchmodels as presented above, asteroid sizes tend to be determined with an orderof magnitude poorer accuracy.References: