[2] Rarahu was discovered on 5 July 1929, by Soviet astronomer Alexander Deutsch at the Simeiz Observatory on the Crimean peninsula.

[14] On July 28, it was independently discovered by Cyril Jackson and Harry Wood at Johannesburg Observatory in South Africa.

[1] In the SMASS classification it is a K-type asteroid, which is a refined spectral type to which most members of the Eos family, including the parent body, belong to.

[1][3] Between 2002 and 2011, three rotational lightcurves of Rarahu were obtained from photometric observations by French amateur astronomers René Roy, Laurent Brunetto and Pierre Antonini.

[5][6][7][8][9] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.1393 and a diameter of 33.23 kilometers based on an absolute magnitude of 10.15.