Results of the Photometric Observations of the NEA (2100) Ra-Shalom During an Encounter in 2019

This paper presents the results of the photometric CCD observations of the NEA (2100) Ra-Shalom carried out on August 24–29, 2019, at the 1-m telescope of the Sanglokh Observatory of the Institute of Astrophysics, National Academy of Sciences of the Republic of Tajikistan. The rotation period P = 19.8 ± 0.1 h was determined. Composite light curves were plotted in the photometric BVR bands; the brightness amplitude ΔV = 0.61m ± 0.05m and the average values of the color indices B–V = 0.75m ± 0.05m, V–R = 0.40m ± 0.02m were determined. Variations in the color indices with rotation period are within the measurement errors, which indicates that the reflectivity of Ra-Shalom’s surface is uniform. The absolute stellar magnitude of the asteroid is 15.91m ± 0.10m. The ratio of the asteroid’s axes a/b = 1.75.