A Census before Rubin of Asteroid Families in the Main Belt

Abstract A collisional family is a collection of ≳kilometer-size asteroid fragments produced by a large-scale collision between asteroids. Here we cataloged 335 notable collisional families in the main asteroid belt. When possible, we estimated each family’s formation age, mean visible albedo, taxonomic type, and parent body size. We found that older families ( t age > 10 Myr) produced by impacts on small parent bodies (diameter D < 5 km) are rarely identified because small members of these families have drifted over time by the Yarkovsky effect and blended with the background. The young families ( t age < 10 Myr) typically have small parent bodies ( D < 10 km) as large asteroids are not disrupted often enough. The full catalog, including membership files for 335 individual asteroid families, is available for download ( https://www.boulder.swri.edu/~davidn/Proper25 ).