(60558) Echeclus
This object has a more recent orbit available here
Object
Object | (60558) Echeclus |
Diameter(1) | 64 km |
Dynamic class(1) | Centaur |
Absolute magnitude | 9.18 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2459800.5 |
Semi major axis | 10.736711 ± 0.000001 au |
Eccentricity | 0.457248066 ± 0.000000078 |
Inclination | 4.343841522 ± 0.000000789 ° |
Longitude of ascending node | 173.190430 ± 0.000048 ° |
Argument of perihelia | 163.315390 ± 0.000048 ° |
Mean anomaly | 74.560110 ± 0.000017 ° |
Orbital period | 35.18 yr |
Ephemeris & Observations
Ephemeris version | NIMAv9 |
Observation file |
omc_ast_NIMAv9.txt |
bsp file | 60558_Echeclus_nima_v9.bsp |
Date of first observation | 1979-09-23 |
Date of last observation | 2021-12-31 |
Number of observations used in the fit | 4403 |
Number of rejected observations | 180 |
Number of DES observations | 0 |
Number of MPC observations | 4401 |
Number of unpublished observations | 182 |
RMS of observations | 0.465 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) |
2022-01 | 0.007 | 0.005 |
2022-07 | 0.007 | 0.005 |
2023-01 | 0.010 | 0.006 |
2023-07 | 0.010 | 0.006 |
2024-01 | 0.014 | 0.008 |
2024-07 | 0.013 | 0.007 |
2025-01 | 0.017 | 0.009 |
2025-07 | 0.016 | 0.008 |
2026-01 | 0.021 | 0.010 |
Ephemeris comparison

Difference between NIMAv9 and JPL90 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.