5861

5861 (minor planet number) is a stony asteroid belonging to the main asteroid belt between Mars and Jupiter. It was discovered on 10 December 1989 by the Lincoln Near-Earth Asteroid Research (LINEAR) program at the White Sands Missile Range in New Mexico. The object's provisional designation was 1989 UC, and it received its permanent number after its orbit was well determined.

The asteroid orbits the Sun with a semi-major axis of approximately 2.5 astronomical units. Its orbital period is about 3.96 Earth years, and it travels on a moderately eccentric path (eccentricity 0.18) with an inclination of around 8 degrees relative to the ecliptic plane. As a background population member, 5861 does not belong to any of the major asteroid families.

Spectral analysis suggests that 5861 has a silicaceous (S-type) composition, typical of asteroids in the inner main belt, indicating a surface rich in silicate minerals and some metal. Its absolute magnitude is 12.4, implying a diameter of roughly 8 to 10 kilometers, assuming an average albedo for S-type bodies. No rotation period or pole orientation has yet been recorded, reflecting the limited observational coverage of this relatively faint object.

5861 has not been named; it retains only its numerical designation. The asteroid is catalogued in the Minor Planet Center database and is observed by both professional and amateur astronomers for orbit refinement.