Dynamical Masses of 20 Asteroids Determined with Gaia DR3 Asteroid Observations

We combined the ground-based and Gaia Data Release 3 (DR3) asteroid observations to determine the masses of 20 asteroids with asteroid–asteroid close encounters. In order to take full advantage of the high-precision observations from Gaia, we use the Fisher information to select appropriate model parameters and the modified Encke's equation of motion to construct a dynamical model complete at the level of observation precision. With diameters from literature, bulk densities of 20 asteroids are derived. The results indicate that the utilization of Gaia DR3 provides substantial benefits in terms of improving mass precision. Among the 20 asteroids analyzed in our study, we find that 10 asteroids achieved a mass precision better than 5%, and 15 asteroids better than 10%.