It was discovered on 26 August 1938, by Belgian astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle.

[19] In the Tholen classification, Sigrid is an F-type asteroid (which agrees with the overall spectral type of the Polanian subgroup).

[5] In August 2006, a rotational lightcurve of Sigrid was obtained from photometric observations at the Mount Tarana and Cecil Observatory in NSW, Australia.

Modelling gave a concurring period of 43.179 and 43.1795 hours,[15][16] as well as two spin axis of (183.0°, 69°) and (350.0°, 69°) in ecliptic coordinates (λ, β).

[5][6][7][8][9][10][11][12][13] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is an albedo of 0.0489 and a diameter of 24.03 kilometers based on an absolute magnitude of 11.99.