It was discovered on 23 August 1938, by Belgian astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle.

[4] It orbits the Sun in the inner asteroid belt at a distance of 1.9–2.5 AU once every 3 years and 3 months (1,191 days).

[3] In August and September 2013, two rotational lightcurves of Marilyn were obtained from photometric observations.

Lightcurve analysis gave a well-defined rotation period of 4.566 and 4.568 hours with a brightness variation of 0.48 and 0.42 magnitude, respectively (U=3/3).

[10][11] Each of the two studies also gave two spin axis in ecliptic coordinates (λ, β): (83.0°, −57°) and (270.0°, –62.0°),[10] as well as (88.0°, −88°) and (267.0°, −66°).