Dust Production of Interstellar Comet 2I/Borisov Throughout Perihelion

Abstract

Abstract The recently discovered comet 2I/Borisov quickly became a prime target for comet observers during its perihelion approach in 2019 December, after it was discovered to be the first comet of interstellar origin. We present our observations and measurements of the dust production between 2019 October, when the interstellar comet became bright enough for small aperture telescopes, and 2020 January, when the comet entered the plane of the Milky Way. We observed the comet for 24 nights using three telescopes in the public iTelescope network. The telescopes spanned both the Northern and Southern hemispheres, were of similar aperture size (0.43–0.51 m), and employed a Johnson–Cousins R C filter. Using these data, we measure an A(0°)f ρ range of 94 ± 14 to 139 ± 34 cm, a dust production rate Q dust range of 11.2 ± 4.4 to 16.4 ± 7.3 kg s−1, and a dust-brightness profile-parameter range of −0.95 ± 0.11 to −1.81 ± 0.20 for the interstellar comet. This work revealed low dust production rates from the comet that remained consistent throughout its apparition, with no notable brightening or increase in dust production throughout the observing campaign.