9639

9639 is the numerical designation of a main‑belt asteroid discovered on 2 March 1994 by astronomers at the Kitami Observatory in Japan. The object was assigned the provisional designation 1994 EK1 before receiving its permanent number once its orbit was well established. 9639 follows an orbit typical of the central region of the asteroid belt, with a semi‑major axis of approximately 2.68 astronomical units, an orbital eccentricity of 0.09 and an inclination of about 4.3 degrees to the ecliptic. Its orbital period is roughly 4.4 Earth years.

Physical observations indicate that 9639 is a stony (S‑type) asteroid, reflecting a moderate albedo of around 0.20. Photometric studies suggest a rotation period near 9.2 hours, although the light‑curve amplitude is small, implying a relatively spheroidal shape. Size estimates based on its brightness and albedo place the diameter in the range of 6–9 kilometres.

The asteroid was later named after a notable figure or place, as per the International Astronomical Union’s naming conventions; the official citation was published in the Minor Planet Circulars in 2002. Apart from its astronomical context, the integer 9639 is an odd composite number, factorable as 3 × 3213, and appears in various numerical sequences but holds no particular significance outside of cataloguing systems.

In catalogues and databases, 9639 serves as an identifier for the asteroid, linking observational data, orbital elements, and historical records for researchers studying the composition and dynamics of the main asteroid belt.