Determination of physical parameters of asteroids based on data from space and ground-based telescopes.

The aim of the project is to create spin and shape models of selected main belt asteroids based on dense ground-based lightcurves and the data from space missions. Research on asteroids is important for understanding the origin and evolution of the whole Solar System. Studying them will allow us to better understand the nature of asteroids. Knowledge of the physical properties of asteroids will also facilitate future space mining. The basis for creating asteroid models are the photomrtric lightcurves, which allows for the determination of various asteroid parameters. The data used to create these brightness changes come from observations conducted by both: professional astronomers and amateurs. Such collaboration enables the accumulation of large amounts of data necessary for modeling. Ground-based observations are also supplemented by data from space missions like TESS anf Gaia. The main modeling tool is the SAGE program, developed in the Astronomical Observatory Institute at Adam Mickiewicz University. Using genetic algorithm it enables to create non-convex spin and shape model for asteroids basing solely on lightcurves. The first source of data is photometric observations of asteroids made by amateur astronomers, who submit the raw observations to the GaiaGOSA service. Another source is data from the Roman Baranowski Telescope (RBT) located in Arizona, obtained by professional astronomers. To create an accurate model, the data from multiple opositions are necessary. Gathered observations display the view of asteroids from different phase angles and ecliptic coordinates. Thanks to this we observe the amount of light incoming from different geometrical orientation of the object. Using advanced genetic algorithm SAGE(Dudziski, Bartczak, 2018)calculates a good approximation of the three-dimensional shape of the asteroid, as well as its rotation period and the orientation of the rotation axis (pole position). We have created the models for large main belt asteroids. Thanks to long and dense lightcurves from TESS mission we were able to determine spin orientation and precise shapes of the asteroids. Moreover, the sparse data from Gaia mission allowed to determine the proper size of asteroids along rotation axis. We are presenting here the results for 59 Elpis,96 Aegleand 134 Sophrosyne. In Fig. 1we show the calculated shape of 96Aegle. In the near future precise models for next objects will be determined.Fig 1: Calculated shape model for 96 Aegle.Bartczak, P. ; Dudziski, G., "Shaping asteroid models using genetic evolution (SAGE)", 2018, Monthly Notices of the Royal Astronomical Society, Volume 473, Issue 4, p.5050-5