The Padua family (FIN: 507), also known as the Lydia family, is a mid-sized family of asteroids of more than a thousand members.
The family is at least 25 million years old. Its members were previously associated to 110 Lydia, and are predominantly X-type asteroids with an albedo of approximately 0.1. Together with the Agnia family, the Padua family is the only other family to have most of its members in a nonlinear secular resonance configuration with more than 75% of its members in a z1 librating state.[1][2][3]: 23
Diameter and albedo figures taken from the LCDB, or, if not available, from JPL's SBDB. Also see category.
Lydia former namesake and potential interloper
In previous works (Zappala et al. 1995), this family was named Lydia after 110 Lydia, which is an X-type asteroid in the SMASS classification (Tholen: M-type). While Lydia is still a member of the now-called Padua family (Nesvorny 2005, AstDyS), it has been suspected that it might be an interloper in its "own" family despite its matching spectral type (Carruba 2009; Mothe-Diniz et al. 2005).[1]: 369
Also, the asteroid 308 Polyxo was formerly considered the family's largest member.[5] This T-type asteroid is no-longer considered a family member and is categorized as a background asteroid on AstDyS.[4][6]