Dust Production Rates in Jupiter-family Comets: A Two Year Study withATLAS Photometry
A. Fraser Gillan, A. Fitzsimmons, L. Denneau, Robert J. Siverd, K. Smith, J. Tonry, D. R. Young
Abstract
Abstract Jupiter-family comets (JFCs) exhibit a wide range of activity levels and mass loss over their orbits. We analyzed high-cadence observations of 42 active JFCs with the wide-field Asteroid Terrestrial-impact Last Alert System (ATLAS) in 2020–2021. We measured the dust production rates of the JFCs using the Af ρ parameter and its variation as a function of heliocentric distance. There is a tendency for our JFC sample to exhibit a maximum Af ρ after perihelion, with 254P/McNaught and P/2020 WJ5 (Lemmon) having their maximum Af ρ over a year after perihelion. On average, the rate of change of activity postperihelion was shallower than preperihelion. We also estimated the maximum mass-loss rate for 17 of the JFCs in our sample, finding 4P/Faye to be the most active. We present a subset of comets whose measured Af ρ have been interpolated and extrapolated to a common distance of 2 au preperihelion and postperihelion. From these measurements we found no correlation of intrinsic activity with current perihelion distance. For three of the JFCs in our sample, 6P/d’Arrest, 156P/Russell–LINEAR, and 254P/McNaught, there was no visible coma but a constant absolute magnitude, which we attribute to a probable detection of the nucleus. We derived upper limits for the nuclear radii of ≤2.1 ± 0.3 km, ≤2.0 ± 0.2 km, and ≤4.0 ± 0.8 km, respectively. Finally, we found that 4P/Faye, 108P/Ciffreo, 132P/Helin–Roman–Alu 2, 141P/Machholz 2, and 398P/Boattini experienced outbursts between 2020 and 2022.