Physical parameters of selected Gaia mass asteroids
Abstract
Context. Thanks to the Gaia mission, it will be possible to determine the masses of approximately hundreds of large main belt asteroids with very good precision. We currently have diameter estimates for all of them that can be used to compute their volume and hence their density. However, some of those diameters are still based on simple thermal models, which can occasionally lead to volume uncertainties as high as 2030%.
Aims: The aim of this paper is to determine the 3D shape models and compute the volumes for 13 main belt asteroids that were selected from those targets for which Gaia will provide the mass with an accuracy of better than 10%.
Methods: We used the genetic Shaping Asteroids with Genetic Evolution (SAGE) algorithm to fit diskintegrated, dense photometric lightcurves and obtain detailed asteroid shape models. These models were scaled by fitting them to available stellar occultation and/or thermal infrared observations.
Results: We determine the spin and shape models for 13 main belt asteroids using the SAGE algorithm. Occultation fitting enables us to confirm main shape features and the spin state, while thermophysical modeling leads to more precise diameters as well as estimates of thermal inertia values.
Conclusions: We calculated the volume of our sample of mainbelt asteroids for which the Gaia satellite will provide precise mass determinations. From our volumes, it will then be possible to more accurately compute the bulk density, which is a fundamental physical property needed to understand the formation and evolution processes of small Solar System bodies.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 June 2020
 DOI:
 10.1051/00046361/201936380
 arXiv:
 arXiv:2001.07030
 Bibcode:
 2020A&A...638A..11P
 Keywords:

 minor planets;
 asteroids: general;
 techniques: photometric;
 radiation mechanisms: thermal;
 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 Accepted for publication in A&