(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| Number of unpublished observations | 48 |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.