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^[1]. Its rotation period is 10.366 hours^[2].

• Lightcurve plot of 839 Valborg, Palmer Divide Observatory, B. D. Warner (2005)
• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• 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
• 839 Valborg at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 839 Valborg at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters