(884) Priamus
This object has a more recent orbit available here
Object
Object | (884) Priamus |
Diameter(1) | 101 km |
Dynamic class(1) | trojan |
Absolute magnitude | 8.74 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2460600.5 |
Semi major axis | 5.207680 ± 0.000000 au |
Eccentricity | 0.124572235 ± 0.000000031 |
Inclination | 8.895517409 ± 0.000001977 ° |
Longitude of ascending node | 301.458262 ± 0.000011 ° |
Argument of perihelia | 337.472192 ± 0.000022 ° |
Mean anomaly | 96.384859 ± 0.000014 ° |
Orbital period | 11.88 yr |
Ephemeris & Observations
Ephemeris version | NIMAv8 |
Observation file |
omc_ast_NIMAv8.txt |
bsp file | 884_Priamus_nima_v8.bsp |
Date of first observation | 1917-09-22 |
Date of last observation | 2024-07-13 |
Number of observations used in the fit | 4616 |
Number of rejected observations | 39 |
Number of DES observations | 0 |
Number of MPC observations | 4650 |
Number of unpublished observations | 5 |
RMS of observations | 3.304 arcsec |
Residuals

Residuals in right ascension and declination compared to NIMAv8 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
date | σα (arcsec) | σδ (arcsec) |
2024-01 | 0.022 | 0.014 |
2024-07 | 0.028 | 0.013 |
2025-01 | 0.031 | 0.015 |
2025-07 | 0.030 | 0.008 |
2026-01 | 0.039 | 0.011 |
2026-07 | 0.030 | 0.005 |
2027-01 | 0.041 | 0.007 |
2027-07 | 0.028 | 0.008 |
2028-01 | 0.036 | 0.014 |
Ephemeris comparison

Difference between NIMAv8 and JPL63 in right ascension (weighted by cos δ) and in declination.
Gray area represents the 1-σ uncertainty of NIMA ephemeris. Green dots represent the DES observations.