Physical parameters of selected Gaia mass asteroids

Abstract

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 20-30%. 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%. We used the genetic Shaping Asteroids with Genetic Evolution (SAGE) algorithm to fit disk-integrated, 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. 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. We calculated the volume of our sample of main-belt 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.

arXiv commentAccepted for publication in A&A

References in corpus (21)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Density of asteroids
• Asteroids Were Born Big
• Combining asteroid models derived by lightcurve inversion with asteroidal occultation silhouettes
• Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - preliminary results
• Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution
• New and updated convex shape models of asteroids based on optical data from a large collaboration network
• The AKARI IRC asteroid flux catalogue: updated diameters and albedos
• 3D shape of asteroid (6)~Hebe from VLT/SPHERE imaging: Implications for the origin of ordinary H chondrites
• Thermophysical properties of near-Earth asteroid (341843) 2008 EV5 from WISE data
• The heart of the swarm: K2 photometry and rotational characteristics of 56 Jovian Trojan asteroids
• Physical characterisation of near-Earth asteroid (1620) Geographos. Reconciling radar and thermal-infrared observations
• Herschel celestial calibration sources: Four large main-belt asteroids as prime flux calibrators for the far-IR/sub-mm range
• Adaptive optics and lightcurve data of asteroids: twenty shape models and information content analysis
• Asteroid models reconstructed from the Lowell Photometric Database and WISE data
• Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids
• Thermal properties of slowly rotating asteroids: Results from a targeted survey
• Shaping Asteroids with Genetic Evolution (SAGE)
• Small Bodies Near and Far (SBNAF): a benchmark study on physical and thermal properties of small bodies in the Solar System
• Shape models of asteroids based on lightcurve observations with BlueEye600 robotic observatory
• Volume uncertainty assessment method of asteroid models from disk-integrated visual photometry

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• The Heterogeneous Surface of Asteroid (16) Psyche
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• Thermal properties of large main-belt asteroids observed by Herschel PACS
• Determination of rotation periods for a large sample of asteroids from K2 Campaign 9
• Probabilistic modeling of asteroid diameters from Gaia DR2 errors
• Asteroid sizes determined with thermophysical model and stellar occultations