One of two subfamilies of asteroids at a mean distance of 2.42 AU from the Sun, the other being the Hertha family. They are close neighbours with a small but distinct difference in orbital inclination. Both consist of a single large asteroid (namely (44) Nysa, diameter 41 km, orbital inclination 3°.7, and (135) Hertha, diameter 79 km, inclination 2°.3) plus many small objects 20 km or less in diameter. Nysa is of E class and Hertha M class, while the minor members of the Nysa subfamily are of the rare F class. Some family members are very close to the Kirkwood gap at the 3 : 1 resonance with Jupiter at 2.50 AU, and could be thrown into the gap to be subsequently ejected into Earth-crossing orbits. This family may therefore be an important source of meteorites. Nysa itself was discovered in 1857 by the German astronomer Hermann Mayer Salomon Goldschmidt (1802–66). Its orbit has a semimajor axis of 2.423 AU, period 3.77 years, perihelion 2.07 AU, aphelion 2.78 AU, and inclination 3°.7. Nysa is notable for its high albedo, over 0.5, the highest of any known asteroid.
Subjects: Astronomy and Astrophysics.