(884) Priamus


Object

Object (884) Priamus
Diameter(1) 101 km
Dynamic class(1) trojan
Absolute magnitude 8.81
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2458600.5
Semi major axis 5.181758 ± 0.000000 au
Eccentricity 0.122676242 ± 0.000000062
Inclination 8.915378702 ± 0.000003312 °
Longitude of ascending node 301.563018 ± 0.000038 °
Argument of perihelia 335.474080 ± 0.000036 °
Mean anomaly 291.306155 ± 0.000048 °
Orbital period 11.80 yr

Ephemeris & Observations

Ephemeris version NIMAv4
Observation file (documentation) omc_ast_NIMAv4.txt
bsp file 884_Priamus_nima_v4.bsp
Date of first observation 1917-09-22
Date of last observation 2020-08-06
Number of observations used in the fit 2738
Number of rejected observations 49
Number of DES observations 0
Number of MPC observations 2785
Number of unpublished observations 2
RMS of observations 0.514 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv4 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2020-01 0.018 0.012
2020-07 0.027 0.021
2021-01 0.032 0.018
2021-07 0.058 0.031
2022-01 0.042 0.023
2022-07 0.066 0.040
2023-01 0.048 0.028
2023-07 0.057 0.033
2024-01 0.051 0.029

Ephemeris comparison

residual plot

Difference between NIMAv4 and JPL32 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.

Previous NIMA versions