(6491) 1991 OA

(6491) 1991 OA is a highly eccentric, stony asteroid, classified as near-Earth object and potentially hazardous asteroid, about half a kilometer in diameter. It was discovered on 16 July 1991, by American astronomer Henry E. Holt at the U.S. Palomar Observatory in California.

The asteroid is an Amor asteroid – a subgroup of near-Earth asteroids that approach the orbit of Earth from beyond, but do not cross it. Its Earth Minimum orbit intersection distance (MOID) is 0.0429 AU, and on 1 August 2086, it will make a close approach and pass by Earth at a distance of 0.09 AU (13,000,000 km).

The S-type asteroid orbits the Sun at a distance of 1.0–4.0 AU once every 3 years and 12 months (1,445 days). Its orbit shows an very high eccentricity of 0.59 and an inclination of 6 degrees from the plane of the ecliptic. A photometric light-curve analysis rendered a rotation period of 2.69 hours with an brightness amplitude of 0.08 in magnitude. The Collaborative Asteroid Lightcurve Link (CALL) assumes an albedo of 0.20 and derives a diameter of 0.53 kilometers.

External links

• 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 (5001)-(10000) – Minor Planet Center
• (6491) 1991 OA at the JPL Small-Body Database

• Discovery · Orbit diagram · Orbital elements · Physical parameters