(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 | 8.32 |
| G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
| Epoch (Julian date) | 2460600.5 |
| Semi major axis | 5.212198 ± 0.000000 au |
| Eccentricity | 0.148450053 ± 0.000000041 |
| Inclination | 10.317503932 ± 0.000003969 ° |
| Longitude of ascending node | 316.539333 ± 0.000018 ° |
| Argument of perihelia | 133.984316 ± 0.000027 ° |
| Mean anomaly | 43.908675 ± 0.000016 ° |
| Orbital period | 11.90 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv8 |
| Observation file |
omc_ast_NIMAv8.txt |
| bsp file | 588_Achilles_nima_v8.bsp |
| Date of first observation | 1906-02-22 |
| Date of last observation | 2024-06-06 |
| Number of observations used in the fit | 4343 |
| Number of rejected observations | 44 |
| Number of DES observations | 0 |
| Number of MPC observations | 4323 |
| Number of unpublished observations | 64 |
| RMS of observations | 3.604 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv8 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2024-01 | 0.030 | 0.021 |
| 2024-07 | 0.022 | 0.014 |
| 2025-01 | 0.032 | 0.021 |
| 2025-07 | 0.027 | 0.018 |
| 2026-01 | 0.034 | 0.019 |
| 2026-07 | 0.034 | 0.021 |
| 2027-01 | 0.035 | 0.016 |
| 2027-07 | 0.041 | 0.021 |
| 2028-01 | 0.034 | 0.015 |
Ephemeris comparison
Difference between NIMAv8 and JPL109 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.