Padua family

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  · LCDB
363 Padua	X	88	0.057	list	JPL  · MPC  · LCDB
1517 Beograd	X	36	0.0448	list	JPL  · MPC  · LCDB
1766 Slipher	C	20	0.057	list	JPL  · MPC  · LCDB
2306 Bauschinger	X	21	0.0526	list	JPL  · MPC  · LCDB
2560 Siegma	Xc	20	0.057	list	JPL  · MPC  · LCDB
3020 Naudts	Sl	16	0.057	list	JPL  · MPC  · LCDB
3670 Northcott	X	19	0.045	list	JPL  · MPC  ·—
5087 Emelʹyanov	X	13	0.057	list	JPL  · MPC  · LCDB
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 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]}

References

1. Carruba, V. (May 2009). "The (not so) peculiar case of the Padua family". Monthly Notices of the Royal Astronomical Society. 395 (1): 358–377. Bibcode:2009MNRAS.395..358C. doi: 10.1111/j.1365-2966.2009.14523.x .
2. Carruba, V.; Domingos, R. C.; Nesvorný, D.; Roig, F.; Huaman, M. E.; Souami, D. (August 2013). "A multidomain approach to asteroid families' identification". Monthly Notices of the Royal Astronomical Society. 433 (3): 2075–2096. arXiv: 1305.4847 . Bibcode:2013MNRAS.433.2075C. doi: 10.1093/mnras/stt884 . S2CID   118511004.
3. Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. arXiv: 1502.01628 . Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN   9780816532131. S2CID   119280014.
4. "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Archived from the original on 16 August 2017. Retrieved 22 July 2017.
5. Ridpath, Ian (2003). Oxford Dictionary of Astronomy. Oxford University Press. ISBN   0199609055 . Retrieved 25 January 2016.
6. "AstDyS-2 data for (308) Polyxo". AstDyS – Asteroids Dynamic Site. Retrieved 30 August 2017.