Nysa family

The Nysa family (adj. Nysian; FIN: 405) is part of the Nysa–Polana complex, the largest cluster of asteroid families in the asteroid belt.^[1]: 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.^[2] 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.

Subdivision

Asteroids in this complex are typically divided into the stony Nysa and carbonaceous Polana subgroups, two mineralogically different families:^[3]

• 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.^[4] More recently an additional family, the Eulalia family has also been identified inside this subgroup.^{[3][1]: 4, 8}

Nysian asteroids

Name	Semimajor axis (a)	orbital eccentricity (e)	inclination (i)
44 Nysa	2.423	0.149	3.703°
135 Hertha	2.428	0.206	2.306°
142 Polana	2.418	0.136	2.238°
750 Oskar	2.444	0.130	3.952°
2984 Chaucer	2.470	0.135	3.054°
2391 Tomita[5]
2509 Chukotka
2710 Veverka
3048 Guangzhou
3069 Heyrovsky
3172 Hirst
3467 Bernheim	2.409	0.149	4.112°
3952 Russellmark
4797 Ako
5075 Goryachev
5394 Jurgens
7629 Foros
7655 Adamries
7866 Sicoli	2.428	0.210	3.480°
9922 Catcheller[6]	2.402	0.190	2.492°

See also

• 101955 Bennu, probably part of the Polana family, visited by the OSIRIS-REx spacecraft in 2018