Dust Production Rates in Jupiter-family Comets. II. Trends and Population Insights from ATLAS Photometry of 116 JFCs

Abstract

Jupiter-family comets (JFCs) have orbital periods of less than 20 yr and therefore undergo more frequent sublimation compared to other comet populations. The JFCs therefore represent the ideal dynamical population for investigating the dust production rates at high cadence. We analyzed observations by the Asteroid Terrestrial-impact Last Alert System (ATLAS) of 74 JFCs that reached perihelion in 2022 and 2023. The work contained in this study builds on our previous work, for a total of 116 JFCs over a 4 yr period. Using the Afρ parameter, we measured the dust production rates of each JFC as a function of heliocentric distance. We found that there remained a clear preference for JFCs to reach their maximum A (0°) fρ post-perihelion, with 170P/Christensen, 254P/McNaught, and P/2020 WJ5 (Lemmon) reaching a maximum A (0°) fρ between 200 and 400 days after perihelion. However, all JFCs reached their maximum dust production within 10% of their orbital period relative to perihelion. Fitting A (0°) fρ as a function of ${({R}_{h})}^{n}$ , we measured statistically significant differences in the distribution of pre-perihelion and post-perihelion activity index n , with average activity indices of −5.2 ± 4.5 and −3.2 ± 2.7, respectively. We derived upper limits for the nuclear radii of comets 444P/WISE-PANSTARRS and 459P/Catalina as R _n ≤ 1.5 ± 0.2 km and R _n ≤ 1.7 ± 0.1 km, respectively. We measured six outbursts in comets 97P/Metcalf-Brewington, 99P/Kowal 1, 118P/Shoemaker-Levy 4, 285P/LINEAR, and 382P/Larson. From our 4 yr of observing JFC outbursts in the ATLAS data, the average increase in magnitude was −1.3 ± 0.8.

Keywords

• Coma dust
• Short period comets
• Time domain astronomy
• Comets
• Broad band photometry
• Wide-field telescopes