(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 | 0.148138703 ± 0.000000010 |
Inclination | 10.319920136 ± 0.000000053 ° |
Longitude of ascending node | 316.534977 ± 0.000001 ° |
Argument of perihelia | 133.588618 ± 0.000003 ° |
Mean anomaly | 337.916816 ± 0.000005 ° |
Orbital period | 11.89 yr |
Ephemeris & Observations
Ephemeris version | NIMAv5 |
Observation file |
omc_ast_NIMAv5.txt |
bsp file | 588_Achilles_nima_v5.bsp |
Date of first observation | 1906-02-22 |
Date of last observation | 2022-07-13 |
Number of observations used in the fit | 3229 |
Number of rejected observations | 40 |
Number of DES observations | 0 |
Number of MPC observations | 3053 |
Number of unpublished observations | 48 |
RMS of observations | 0.123 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv5 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
date | σα (arcsec) | σδ (arcsec) |
2022-01 | 0.009 | 0.005 |
2022-07 | 0.011 | 0.002 |
2023-01 | 0.018 | 0.002 |
2023-07 | 0.014 | 0.003 |
2024-01 | 0.022 | 0.009 |
2024-07 | 0.014 | 0.007 |
2025-01 | 0.018 | 0.011 |
2025-07 | 0.015 | 0.009 |
2026-01 | 0.016 | 0.008 |
Ephemeris comparison
Difference between NIMAv5 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.