(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 |
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| Number of unpublished observations | 50 |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
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
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.