Testing the inversion of Gaia photometry of asteroids

Toni Santana-Ros, Przemysław Bartczak, Tadeusz Michałowski, Paolo Tanga and Alberto Cellino

We studied the performance of the Gaia inversion algorithm under different scenarios. The test consisted of feeding the algorithm with several sets of photometric simulations for ten thousand asteroids having different spin axis orientations, rotational periods and shapes, including binaries. We used the Gaia mission simulator to generate the observational epochs, while the brightnesses were generated using a Z-buffer standard graphic method. It was found that results are biased against asteroids presenting low lightcurve amplitude and low pole latitudes. The analysis of the inversion results led to the confirmation that synchronous binary systems can be successfully modelled with a simple triaxial ellipsoid body. On the basis of these simulations, it was also possible to develop strategies for binary asteroid detection. The presented quantitative results include the semi-major axis values of the triaxial ellipsoid model with a high probability of hosting binary systems. We also present the Gaia-Groundbased Observation Service for Asteroids (Gaia-GOSA), which aims to support ground-based observation campaigns of asteroids.

Proceedings of the Polish Astronomical Society, vol. 3, 91-97 (2016)

Download full article as PDF file: