It orbits the Sun at a distance of 4.5–5.8 AU once every 11 years and 10 months (4,308 days; semi-major axis of 5.18 AU). Its orbit has an eccentricity of 0.12 and an inclination of 9° with respect to the ecliptic.[4] The body's observation arc begins at Heidelberg in November 1917, two months after its official discovery observation.[1]
Between January 2015, and December 2016, photometric observations by Robert Stephens and Daniel Coley in collaboration with Brian Warner at the Center for Solar System Studies, California, gave a three concurring periods of 6.854, 6.863 and 6.865 hours (U=3/3/3).[17][18][19][a]
Diameter and albedo
According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Priamus measures 101.09 and 119.99 kilometers in diameter and its surface has an albedo of 0.044 and 0.037, respectively.[8][9] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 96.29 kilometers based on an absolute magnitude of 8.81.[5]
100+ largest Jupiter trojans
Largest Jupiter Trojans by survey(A) (mean-diameter in kilometers; YoD: Year of Discovery)
Note: missing data was completed with figures from the JPL SBDB (query) and from the LCDB (query form) for the WISE/NEOWISE and SIMPS catalogs, respectively. These figures are given in italics. Also, listing is incomplete above #100.
Notes
^Lightcurve plots of (884) Priamus from Jan 2015, Jan 2016 and Dec 2016 by Daniel Coley and Robert Stephens at the Center for Solar System Studies (U80) and (U81). Quality code is 3/3/3 (lightcurve rating at CS3). Summary figures at the LCDB and CS3.
^ abcdUsui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)