It was discovered by Belgian astronomer Eric Elst at ESO's La Silla Observatory in northern Chile on 17 April 1996.
[1] This minor planet was named from Greek mythology after the Trojan warrior Demoleon, son of Antenor, who was a counselor to King Priam.
[9] In November 2014, a rotational lightcurve of Demoleon was obtained over a total of seven nights of photometric observations by Robert Stephens at the Center for Solar System Studies in Landers, California.
Lightcurve analysis gave a rotation period of 14.43±0.01 hours with a brightness amplitude of 0.18 magnitude (U=2).
[8][a] According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Demoleon measures 33.47 kilometers in diameter and its surface has an albedo of 0.083,[6] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 40.33 kilometers based on an absolute magnitude of 10.7.