OpenOrb: Open-source asteroid orbit computation software including statistical ranging

We are making an open-source asteroid orbit computation software package called OpenOrb publicly available. OpenOrb is built on a well-established Bayesian inversion theory, which means that it is to a large part complementary to orbit-computation packages currently available. In particular, OpenOrb is the first package that contains tools for rigorously estimating the uncertainties resulting from the inverse problem of computing orbital elementsusing scarce astrometry. In addition to the well-known least-squares method, OpenOrb also contains both Monte-Carlo (MC) and Markov-Chain MC (MCMC; Oszkiewicz et al. (2009)) versions of the statistical ranging method. Ranging allows the user to obtain sampled, non- Gaussian orbital-element probability-density functions and is therefore optimized for cases where the amount of astrometryis scarce or spans a relatively short time interval. Ranging-based methods have successfully been applied to a variety of different problems such as rigorous ephemerisprediction, orbital elementdistribution studies for transneptunian objects, the computation of invariant collision probabilities between near-Earth objectsand the Earth, detection of linkages between astrometric asteroid observations within an apparition as well as between apparitions, and in the rigorous analysis of the impact of orbital arc lengthand/or astrometric uncertainty on the uncertainty of the resulting orbits. Tools for making ephemerispredictions and for classifying objects based on their orbits are also available in OpenOrb. As an example, we use OpenOrb in the search for candidate retrograde and/or high-inclination objects similar to 2008 KV42 in the known population of transneptunian objects that have an observational time span shorter than 30 days.