(60558) Echeclus


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 ± 0.000001 au
Eccentricity 0.456454696 ± 0.000000074
Inclination 4.343405950 ± 0.000001266 °
Longitude of ascending node 173.303957 ± 0.000046 °
Argument of perihelia 162.808699 ± 0.000046 °
Mean anomaly 41.343953 ± 0.000010 °
Orbital period 34.96 yr

Ephemeris & Observations

Ephemeris version NIMAv8
Observation file (documentation) omc_ast_NIMAv8.txt
bsp file 60558_Echeclus_nima_v8.bsp
Date of first observation 1979-09-23
Date of last observation 2021-01-19
Number of observations used in the fit 4259
Number of rejected observations 176
Number of DES observations 0
Number of MPC observations 4253
Number of unpublished observations 182
RMS of observations 0.466 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv8 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2021-01 0.004 0.003
2021-07 0.005 0.003
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

Ephemeris comparison

residual plot

Difference between NIMAv8 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.

Previous NIMA versions