(588) Achilles


This object has a more recent orbit available here

Object

Object (588) Achilles
Diameter(1) 130 km
Dynamic class(1) trojan
Absolute magnitude 8.27
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2459800.5
Semi major axis 5.209204 ± 0.000000 au
Eccentricity 0.148138753 ± 0.000000047
Inclination 10.319917523 ± 0.000004302 °
Longitude of ascending node 316.534959 ± 0.000020 °
Argument of perihelia 133.588646 ± 0.000028 °
Mean anomaly 337.916821 ± 0.000017 °
Orbital period 11.89 yr

Ephemeris & Observations

Ephemeris version NIMAv6
Observation file (documentation) omc_ast_NIMAv6.txt
bsp file 588_Achilles_nima_v6.bsp
Date of first observation 1906-02-22
Date of last observation 2022-11-13
Number of observations used in the fit 3342
Number of rejected observations 40
Number of DES observations 0
Number of MPC observations 3332
Number of unpublished observations 50
RMS of observations 4.106 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv6 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2022-01 0.014 0.015
2022-07 0.016 0.014
2023-01 0.027 0.023
2023-07 0.023 0.015
2024-01 0.040 0.025
2024-07 0.028 0.017
2025-01 0.040 0.026
2025-07 0.033 0.021
2026-01 0.040 0.022

Ephemeris comparison

residual plot

Difference between NIMAv6 and JPL97 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.