1825 Klare

1825 Klare (prov. designation: ) is a background asteroid from the central region of the asteroid belt, approximately 15 kilometers in diameter. It was discovered on 31 August 1954, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany. The asteroid was named after Heidelberg astronomer Gerhard Klare.

Orbit and classification
The presumably stony asteroid orbits the Sun in the central main-belt at a distance of 2.4–3.0 AU once every 4 years and 5 months (1,600 days). Its orbit has an eccentricity of 0.11 and an inclination of 4° with respect to the ecliptic. First identified as at Uccle Observatory in 1934, Klare's observation arc begins 20 years prior to its official discovery observation.

Naming
Klare was named after Gerhard Klare (born 1932), an observing astronomer at Heidelberg Observatory since 1960, whose fields of interest include minor planets. He is also known for his numerous contributions in the yearbook series "Reviews in Modern Astronomy" of the Astronomische Gesellschaft. The official was published by the Minor Planet Center on 18 April 1977 (M.P.C. 4156).

Rotation period
Klare has been the subject of multiple photometric lightcurve studies, which gave a well-determined rotation period between 4.741 and 4.744 hours with a brightness variation between 0.70 and 0.90 magnitude (U=3/n.a.). Measurements have also been used as the basis for generating a three-dimensional model of its shape. The Collaborative Asteroid Lightcurve Link (CALL) adopts a period 4.744 hours with an amplitude of 0.70 magnitude (U=3).

Diameter and albedo
According to the survey carried out by the Japanese Akari satellite, Klare measures 14.69 kilometers in diameter, and its surface has an albedo of 0.167, while CALL assumes an albedo of 0.10 – a compromise value for asteroids with a semi-major axis between 2.6 and 2.7 AU, for which neither a S (0.20) nor a C (0.057) type has been determined – and calculates a diameter of 19.21 kilometers with an absolute magnitude of 11.7.