(65489) Ceto


Object

Object (65489) Ceto
Diameter(1) 223 km
Dynamic class(1) Centaur
Absolute magnitude 6.45
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2460800.5
Semi major axis 100.082937 ± 0.008578 au
Eccentricity 0.823143732 ± 0.000014031
Inclination 22.302656395 ± 0.000035983 °
Longitude of ascending node 172.003141 ± 0.000116 °
Argument of perihelia 319.358537 ± 0.000751 °
Mean anomaly 12.860521 ± 0.001692 °
Orbital period 1001.26 yr

Ephemeris & Observations

Ephemeris version NIMAv4
Observation file (documentation) omc_ast_NIMAv4.txt
bsp file 65489_Ceto_nima_v4.bsp
Date of first observation 1987-01-31
Date of last observation 2025-05-27
Number of observations used in the fit 227
Number of rejected observations 6
Number of DES observations 0
Number of MPC observations 233
Number of unpublished observations 0
RMS of observations 0.269 arcsec

Residuals

residual plot

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)
2024-01 0.165 0.074
2024-07 0.151 0.073
2025-01 0.185 0.077
2025-07 0.170 0.076
2026-01 0.205 0.080
2026-07 0.190 0.079
2027-01 0.225 0.082
2027-07 0.211 0.081
2028-01 0.246 0.085

Ephemeris comparison

residual plot

Difference between NIMAv4 and JPL12 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