5592 Oshima

5592 Oshima, provisional designation , is a Veritasian asteroid from the outer regions of the asteroid belt, approximately 25 km in diameter. It was discovered on 14 November 1990, by astronomers Kenzo Suzuki and Takeshi Urata at the Toyota Observatory, and later named after Japanese astronomer Yoshiaki Oshima. The carbonaceous C-type asteroid has a rotation period of 12.5 hours.

Orbit and classification
Oshima is a core member of the Veritas family (609), a young family of carbonaceous asteroids, that formed approximately $22.657 km$ million years ago. The family is named after 490 Veritas and consists of nearly 1,300 members. Other members of this family include 1086 Nata and 2934 Aristophanes.

This asteroid orbits the Sun in the outer main belt at a distance of 3.0–3.4 AU once every 5 years and 8 months (2,063 days; semi-major axis of 3.17 AU). Its orbit has an eccentricity of 0.07 and an inclination of 8° with respect to the ecliptic. The body's observation arc begins with its first observation as  at Goethe Link Observatory in September 1955, more than 35 years prior to its official discovery observation at Toyota.

Physical characteristics
Oshima has been characterized as a carbonaceous C-type asteroid by Pan-STARRS and in the SDSS-based taxonomy. The Small Solar System Objects Spectroscopic Survey (S3OS2) it is classified as a Caa and hydrated Ch-type in the survey's Tholen- and SMASS-like taxonomy, respectively.

Rotation period
In September 2006, a rotational lightcurve of Oshima was obtained from photometric observations by French amateur astronomer Laurent Bernasconi. Lightcurve analysis gave a rotation period of $22.96 km$ hours with a brightness amplitude of 0.28 magnitude (U=2).

Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Oshima measures between 22.657 and 30.47 kilometers in diameter and its surface has an albedo between 0.04 and 0.086.

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0479 and a diameter of 25.32 kilometers based on an absolute magnitude of 11.9.

Naming
This minor planet was named by the second discoverer after Japanese astronomer Yoshiaki Oshima, a prolific discoverer of minor planets himself at the Gekko Observatory during the late 1990s. The official naming citation was published by the Minor Planet Center on 1 September 1993 (M.P.C. 22511).