It was discovered on 24 October 1976, by Danish astronomer Richard Martin West at the ESO's La Silla Observatory in Chile.
[1] The dark Jovian asteroid has a rotation period of 16.4 hours and belongs to the 100 largest Jupiter trojans.
[7] In June 2016, a rotational lightcurve of Stentor was obtained from photometric observations by Brian Warner at the Center for Solar System Studies (CS3) in California.
[7][8][a] Stentor was previously observed at CS3 by Daniel Coley and Robert Stephens in February 2013, gave an alternative period solution of 35.14±0.02 hours with an amplitude of 0.09 magnitude.
[9] According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Stentor measures 50.76 kilometers in diameter and its surface has an albedo 0.082,[6] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 58.29 kilometers based on an absolute magnitude of 9.9.