839 Valborg is a mid-sized S-type Eunomian asteroid. Its diameter is about 20 km, its albedo of 0.353 is very high for an asteroid. Its rotation period is 10.366 hours. References External links Lightcurve plot of 839 Valborg, Palmer Divide Observatory, B. D. Warner (2005) Asteroid Lightcurve Database (LCDB), query form (info ) 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 000839 Discoveries by Max Wolf Named minor planets 000839 19160924