The Nysa family (adj. Nysian; FIN: 405) is part of the Nysa–Polana complex, the largest cluster of asteroid families in the asteroid belt.:23 It is located in the inner region of the asteroid belt, orbiting the Sun between 2.41 and 2.5 AU. Asteroids in this complex have eccentricities between 0.12 and 0.21 and inclinations of 1.4 to 4.3. The family derives its name from its most massive member, 44 Nysa. It has also been known as the Hertha family (adj. Herthian) named after 135 Hertha.
Asteroids in this complex are typically divided into the stony Nysa and carbonaceous Polana subgroups, two mineralogically different families:
- The much brighter S-type Nysian subgroup (i.e. the Nysa family, in the narrower sense) includes 44 Nysa and 135 Hertha.
- In the low-albedo subgroup of the complex lies the Polana family (adj Polanian), a family of dark F-type asteroids named after 142 Polana, the largest asteroid in this section. More recently an additional family, the Eulalia family has also been identified inside this subgroup.:4,8
- 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.
- EasySky - Screenshots
- Walsh, Kevin J.; Delbó, Marco; Bottke, William F.; Vokrouhlický, David; Lauretta, Dante S. (July 2013). "Introducing the Eulalia and new Polana asteroid families: Re-assessing primitive asteroid families in the inner Main Belt". Icarus. 225 (1): 283–297. arXiv:1305.2821. Bibcode:2013Icar..225..283W. doi:10.1016/j.icarus.2013.03.005.
- "[5.05] The puzzling case of the Nysa-Polana family finally solved?". AAS. Madison. 12 October 1998. Archived from the original on December 17, 2006.
- A. Cellino; V. Zappala; A. Doressoundiram; M. Di Martino; et al. (August 2001). "The Puzzling Case of the Nysa-Polana Family". Icarus. 152 (2): 225–237. Bibcode:2001Icar..152..225C. doi:10.1006/icar.2001.6634.
- Zappalà, V.; Bendjoya, Ph.; Cellino, A.; Farinella, P.; Froeschle, C. (1997). "Asteroid Dynamical Families". NASA Planetary Data System: EAR-A-5-DDR-FAMILY-V4.1. Retrieved 4 March 2020.} (PDS main page)