(588) Achilles
Object
| Object |
(588) Achilles |
| Diameter(1) |
130 km |
| Dynamic class(1) |
trojan |
| Absolute magnitude |
8.31 |
| G slop |
0.15 |
Orbital elements
| Epoch (Julian date) |
2460800.5 |
| Semi major axis |
5.213512 ± 0.000000 au |
| Eccentricity |
0.148409043 ± 0.000000034 |
| Inclination |
10.316328036 ± 0.000003965 ° |
| Longitude of ascending node |
316.537054 ± 0.000018 ° |
| Argument of perihelia |
134.109082 ± 0.000026 ° |
| Mean anomaly |
60.369165 ± 0.000016 ° |
| Orbital period |
11.90 yr |
Ephemeris & Observations
| Ephemeris version |
NIMAv9 |
| Observation file (documentation) |
omc_ast_NIMAv9.txt |
| bsp file |
588_Achilles_nima_v9.bsp |
| Date of first observation |
1906-02-22 |
| Date of last observation |
2025-07-12 |
| Number of observations used in the fit |
4964 |
| Number of rejected observations |
44 |
| Number of DES observations |
0 |
| Number of MPC observations |
4944 |
| Number of unpublished observations |
64 |
| RMS of observations |
3.371 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv9 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date |
σα (arcsec) |
σδ (arcsec) |
| 2024-01 |
0.026 |
0.020 |
| 2024-07 |
0.018 |
0.012 |
| 2025-01 |
0.027 |
0.018 |
| 2025-07 |
0.022 |
0.015 |
| 2026-01 |
0.028 |
0.016 |
| 2026-07 |
0.029 |
0.019 |
| 2027-01 |
0.030 |
0.015 |
| 2027-07 |
0.035 |
0.020 |
| 2028-01 |
0.029 |
0.014 |
Ephemeris comparison
Difference between NIMAv9 and JPL114 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.
Previous NIMA versions