(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 | 0.148138755 ± 0.000000046 |
| Inclination | 10.319917607 ± 0.000004173 ° |
| Longitude of ascending node | 316.534960 ± 0.000019 ° |
| Argument of perihelia | 133.588645 ± 0.000027 ° |
| Mean anomaly | 337.916820 ± 0.000017 ° |
| Orbital period | 11.89 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv7 |
| Observation file |
omc_ast_NIMAv7.txt |
| bsp file | 588_Achilles_nima_v7.bsp |
| Date of first observation | 1906-02-22 |
| Date of last observation | 2023-04-12 |
| Number of observations used in the fit | 3577 |
| Number of rejected observations | 44 |
| Number of DES observations | 0 |
| Number of MPC observations | 3571 |
| Number of unpublished observations | 50 |
| RMS of observations | 3.970 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv7 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2023-01 | 0.026 | 0.022 |
| 2023-07 | 0.022 | 0.015 |
| 2024-01 | 0.038 | 0.024 |
| 2024-07 | 0.027 | 0.016 |
| 2025-01 | 0.039 | 0.026 |
| 2025-07 | 0.033 | 0.021 |
| 2026-01 | 0.039 | 0.022 |
| 2026-07 | 0.039 | 0.024 |
| 2027-01 | 0.039 | 0.017 |
Ephemeris comparison
Difference between NIMAv7 and JPL103 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.