92 Undina

92 Undina (from Latin Undīna) is a large main belt asteroid. The asteroid was discovered by Christian Peters on 7 July 1867 from the Hamilton College Observatory.<ref name=Watson1867/> It is named for the eponymous heroine of Undine, a popular novella by Friedrich de la Motte Fouqué.

This minor planet is orbiting at a distance of around 3 AU from the Sun, which is known for a concentration of Tholen M-type asteroids. Indeed, 92 Undina has an unusually high albedo of 0.25 and an M-type spectrum, or Xc-type on the Bus taxonomy.<ref name=Fornasier2011/> However, it displays absorption features at a wavelength of 3 μm, which is usually indicative of hydrated silicates on the surface.<ref name=Burbine1994/> There is a faint band in the region of 9 μm that is typically attributed to a form of orthopyroxene having low levels of calcium and iron. The spectrum of 92 Undina closely resembles powdered material from the Esquel meteorite, although with a higher albedo.<ref name=Fornasier2011/>

Observations performed at the Palmer Divide Observatory in Colorado Springs, Colorado during 2007 produced a light curve with a period of 15.941 ± 0.002 hours with a brightness range of 0.20 ± 0.02 in magnitude. This matches a 15.94-hour period reported in 1979.<ref name="Warner2007"/> Attempts in 2014 to model the spin axis and shape based on light curve information proved inconclusive, but did indicate that "the pole latitude is not far removed from the ecliptic plane and rotation is probably retrograde".<ref name=Warner2014/>

External links

• Lightcurve plot of 92 Undina, Palmer Divide Observatory, B. D. Warner (2011)
• Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• Template:AstDys
• Template:JPL small body