It was discovered on 22 August 1949, by South African astronomer Ernest Leonard Johnson at the Union Observatory in Johannesburg.
Based on its low albedo, measured by the Wide-field Infrared Survey Explorer (WISE), Raab is possibly C-type asteroid.
[2] In December 2011, a rotational lightcurve of Raab was obtained from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California.
[10] Lightcurve analysis gave a rotation period of 274.944 hours with a brightness amplitude of 0.09 magnitude.
[2][4] According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's WISE telesecope, Raab measures between 15.28 and 19.280 kilometers in diameter and its surface has an albedo between 0.036 and 0.086.