(588) Achilles
Object
| Object |
(588) Achilles |
| Diameter(1) |
130 km |
| Dynamic class(1) |
trojan |
| Absolute magnitude |
8.26 |
| G slop |
0.15 |
Orbital elements
| Epoch (Julian date) |
2456468.249406684 |
| Semi major axis |
5.199067 ± 0.000001 au |
| Eccentricity |
0.148169636 ± 0.000000057 |
| Inclination |
10.317133259 ± 0.000006667 ° |
| Longitude of ascending node |
316.593823 ± 0.000031 ° |
| Argument of perihelia |
133.112313 ± 0.000072 ° |
| Mean anomaly |
61.516921 ± 0.000046 ° |
| Orbital period |
11.85 yr |
Ephemeris & Observations
| Ephemeris version |
NIMAv4 |
| Observation file (documentation) |
omc_ast_NIMAv4.txt |
| bsp file |
588_Achilles_nima_v4.bsp |
| Date of first observation |
1906-02-22 |
| Date of last observation |
2020-11-14 |
| Number of observations used in the fit |
2368 |
| Number of rejected observations |
34 |
| Number of DES observations |
0 |
| Number of MPC observations |
2354 |
| Number of unpublished observations |
48 |
| RMS of observations |
4.874 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv4 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date |
σα (arcsec) |
σδ (arcsec) |
| 2021-01 |
0.008 |
0.009 |
| 2021-07 |
0.019 |
0.015 |
| 2022-01 |
0.025 |
0.024 |
| 2022-07 |
0.036 |
0.023 |
| 2023-01 |
0.060 |
0.036 |
| 2023-07 |
0.048 |
0.024 |
| 2024-01 |
0.075 |
0.042 |
| 2024-07 |
0.049 |
0.028 |
| 2025-01 |
0.060 |
0.038 |
Ephemeris comparison
Difference between NIMAv4 and JPL88 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