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.
The Paduan (Lydian) asteroids are located in the outer part of the central asteroid belt having a semi-major axis of approximately 2.75. The family's namesake is the asteroid 363 Padua, while 110 Lydia is now a suspected interloper, despite having the same spectral type.
Some prominent members with known spectral type. A list of all Paduan aststeroids is given at the "Small Bodies Data Ferret".
| width=120 | Name | Type | Diameter | Albedo | Catalog | Refs | |
|---|---|---|---|---|---|---|---|
| align=center | X | align=center | 86 | 0.1808 | |||
| align=center | X | align=center | 88 | 0.057 | |||
| align=center | X | align=center | 36 | 0.0448 | |||
| align=center | C | align=center | 20 | 0.057 | |||
| align=center | X | align=center | 21 | 0.0526 | |||
| align=center | Xc | align=center | 20 | 0.057 | |||
| align=center | Sl | align=center | 16 | 0.057 | |||
| align=center | X | align=center | 19 | 0.045 | — | ||
| align=center | X | align=center | 13 | 0.057 | |||
| align=center | X | align=center | 12 | 0.074 | — | ||
| align=center | C | align=center | 11 | 0.058 | — | ||
| align=center | X | align=center | 16 | 0.032 | — | ||
| Diameter and albedo figures taken from the LCDB, or, if not available, from JPL's SBDB. Also see category. |
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).
Also, the asteroid 308 Polyxo was formerly considered the family's largest member. This T-type asteroid is no-longer considered a family member and is categorized as a background asteroid on AstDyS.