Determining Physical Characteristics of the Asteroid 572 Rebekka through Analysis of its Lightcurve​

1 page.Here we present observations of the asteroid 572 Rebekka that were obtained in August 2020 at Pine Mountain Observatory (PMO). The target was observed with the 0.35m Robbins telescope at PMO, using a Sloan g’ filter, for a total of 8.5 hours over three nights. The observations produced 605 images of the target which were then analyzed to produce a “lightcurve” of the asteroid. Through photometric analysis of the lightcurve, we have produced a 3-dimensional model of the asteroid which is presented here. Using the programs MPO Canopus (MPO) and Aperture Photometry Tool (APT), photometric estimates of the asteroid’s brightness over time are plotted in order to extract the rotation period as well as the shape of the target. To calibrate this data, we compare the asteroid to multiple stars of constant brightness within the same image. This process, known as “relative photometry”, allows us to remove atmospheric effects due to air quality, light pollution, and changing air mass. An estimate for the change in magnitude due to air mass, commonly known as the extinction coefficient, is also made. These findings give confidence in PMO’s ability to provide research-grade data and serves as an exercise in analyzing and reducing large sets of data. As a collaboration with Kobe University in Japan, this is a continuing project that looks to familiarize students with data analysis, calibration, and astronomical concepts.