Measuring the Distances to Asteroids from One Observatory in One Night with Upcoming All-sky Telescopes

Upcoming telescopes like the Vera Rubin Observatory and the Argus Array will image large fractions of the sky multiple times per night, yielding numerous near-Earth object (NEO) discoveries. When asteroids are measured with short observation time windows, the dominant uncertainty in orbit construction is due to distance uncertainty to the NEO. One approach to recover distances is from , which is a technique that leverages the rotation of the Earth, causing a small but detectable sinusoidal additive signal to the R.A. of the NEO following a period of 1 day. In this paper, we further develop and evaluate this technique to recover distances in as quickly as a single night. We first test the technique on synthetic data of 20 different asteroids ranging from ∼0.05 to ∼2.4 au. We modify previous algorithms and recover distances with uncertainties as low as the ∼4.0% level for more nearby objects (≲0.3 au) when assuming astrometric uncertainties of ∼0 02. We then acquire our own observations of two asteroids within a single night and find we are able to recover distances to the 3% level. We also compare results with the software package and quantify the limitations of our method. We show with that for nearby asteroids, orbits are significantly better constrained when the topocentric parallax is measured with a diversity of observation hour angles rather than without this diversity.

Duke Scholars

Author Daniel M. Scolnic Physics