The astorb database at Lowell Observatory

The astorb database at Lowell Observatory is an actively curated catalog of orbital elements for all known asteroids in the Solar System. astorb has heritage dating back to the 1970’s and has been publicly accessible since the 1990's. Beginning in 2015 work began to modernize astorb’s underlying database infrastructure, operational software, and associated web applications. We will present the latest additions to the astorb ecosystem.

Recent work has involved the expansion of astorb to incorporate physical properties from a variety of sources. These data products include lightcurve properties, photometric colors, spectral types, albedos and diameters, masses and densities, dynamical families, and Main Belt source region probabilities for near-Earth objects (NEOs). The latter represent the first public access to the medium resolution (δa=0.05 AU, δe = 0.02, δi = 2°, δH = 0.25 mag) NEO source region model from Granvik et al. (2018, Icarus 312, 181).

The data in astorb are used to support a number of visualization and observational planning tools hosted at https://asteroid.lowell.edu. These tools include a finder chart generator (called AstFinder), flexible ephemeris calculator (AstEph), and the means for long-term observability assessment (AstObs). Direct queries to the database are facilitated for individual objects (AstInfo), and for lists of objects that meet observability criteria that are either user-defined (UpObjects) or in preset critical lists. More comprehensive access to the database will be enabled in Fall 2021 through a web-based query-building tool built upon an application programming interface (API).

Lastly, we have developed a novel orbit integration scheme that is built upon the GENGA (Gravitational Encounters in N-body simulations with GPU Acceleration; Grimm & Stadel, ApJ 796, 23) hybrid symplectic integrator. By leveraging the massively parallel computing capability of a GPU we can more efficiently maintain the orbital elements in astorb. We have validated the output of GENGA against more traditional direct integrators and find the agreement to be excellent for the vast majority of astorb use cases, i.e. determining observability within months or a few years of the current epoch.