(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 | 9.50 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2458600.5 |
Semi major axis | 10.690937 ± 0.000002 au |
Eccentricity | 0.456454677 ± 0.000000112 |
Inclination | 4.343406390 ± 0.000002733 ° |
Longitude of ascending node | 173.303520 ± 0.000122 ° |
Argument of perihelia | 162.809124 ± 0.000122 ° |
Mean anomaly | 41.343964 ± 0.000015 ° |
Orbital period | 34.96 yr |
Ephemeris & Observations
Ephemeris version | NIMAv7 |
Observation file |
omc_ast_NIMAv7.txt |
bsp file | 60558_Echeclus_nima_v7.bsp |
Date of first observation | 1979-09-23 |
Date of last observation | 2020-03-21 |
Number of observations used in the fit | 649 |
Number of rejected observations | 3785 |
Number of DES observations | 0 |
Number of MPC observations | 4253 |
Number of unpublished observations | 181 |
RMS of observations | 0.545 arcsec |
Residuals

Residuals in right ascension and declination compared to NIMAv7 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
date | σα (arcsec) | σδ (arcsec) |
2020-01 | 0.005 | 0.004 |
2020-07 | 0.008 | 0.004 |
2021-01 | 0.013 | 0.007 |
2021-07 | 0.015 | 0.008 |
2022-01 | 0.022 | 0.013 |
2022-07 | 0.021 | 0.013 |
2023-01 | 0.029 | 0.017 |
2023-07 | 0.027 | 0.016 |
2024-01 | 0.036 | 0.021 |
Ephemeris comparison

Difference between NIMAv7 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.