It was discovered on 15 September 1941, by Belgian astronomer Fernand Rigaux at the Royal Observatory of Belgium in Uccle.

It orbits the Sun in the central asteroid belt at a distance of 1.9–3.4 AU once every 4 years and 5 months (1,610 days).

[2] In September 2016, a rotational lightcurve of Dejan was obtained from photometric observations by the Spanish amateur astronomer group OBAS.

Lightcurve analysis gave a rotation period of 16.960 hours with a brightness variation of 0.41 magnitude (U=2+).

[8] According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Dejan measures 21.77 and 23.199 kilometers in diameter and its surface has an albedo of 0.053 and 0.08, respectively,[4][5][6] while the Japanese Akari satellite found a diameter of 24.04 kilometers with an albedo of 0.068.