Padua family
Asteroid family
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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
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.[1][3]: 23
Members
Some prominent members with known spectral type.[1]: 364 A list of all Paduan asteroids is given at the "Small Bodies Data Ferret".[4]
| Name | Type | Diameter | Albedo | Catalog | Refs |
|---|---|---|---|---|---|
| 110 Lydia | X | 86 | 0.1808 | list | JPL · MPC |
| 363 Padua | X | 88 | 0.057 | list | JPL · MPC |
| 1517 Beograd | X | 36 | 0.0448 | list | JPL · MPC |
| 1766 Slipher | C | 20 | 0.057 | list | JPL · MPC |
| 2306 Bauschinger | X | 21 | 0.0526 | list | JPL · MPC |
| 2560 Siegma | Xc | 20 | 0.057 | list | JPL · MPC |
| 3020 Naudts | Sl | 16 | 0.057 | list | JPL · MPC |
| 3670 Northcott | X | 19 | 0.045 | list | JPL · MPC |
| 5087 Emelʹyanov | X | 13 | 0.057 | list | JPL · MPC |
| 5103 Diviš | X | 12 | 0.074 | list | JPL · MPC |
| 8450 Egorov | C | 11 | 0.058 | list | JPL · MPC |
| 12281 Chaumont | X | 16 | 0.032 | list | JPL · MPC |
| Diameter and albedo figures taken 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]