Asteroid Period Solutions from Combined Dense and Sparse Photometry

Deriving high quality lightcuves for asteroids and other periodic sources from survey data is challenging due to many factors, including the sparsely sampled observational record and diurnal aliasing which is a signature imparted into the periodic signal of a source that is a function of the observing schedule of ground-based telescopes. In this paper, we examine the utility of combining asteroid observational records from the Zwicky Transient Facility (ZTF) and the Transiting Exoplanet Survey Satellite (TESS) which are the ground- and space-based facilities, respectively, to determine to what degree the data from the space-based facility can suppress diurnal aliases. Furthermore, we examine several optimizations that are used to derive the rotation periods of asteroids which we then compare to the reported rotation periods in the literature. Through this analysis we find that we can reliably derive the rotation periods for ~85% of our sample of 222 objects that are also reported in the literature and that the remaining ~15% are difficult to reliably derive as many are asteroids that are insufficiently elongated which produces a lightcurve with an insufficient amplitude and consequently, an incorrect rotation period. We also investigate a binary classification method that biases against reporting incorrect rotation periods. We conclude the paper by assessing the utility of using other ground- or space-based facilities as companion telescopes to the forthcoming Rubin Observatory.