(1583) Antilochus


This object has a more recent orbit available here

Object

Object (1583) Antilochus
Diameter(1) 109 km
Dynamic class(1) trojan
Absolute magnitude 8.62
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2459800.5
Semi major axis 5.141840 ± 0.000000 au
Eccentricity 0.053780183 ± 0.000000043
Inclination 28.492331714 ± 0.000003809 °
Longitude of ascending node 221.381893 ± 0.000006 °
Argument of perihelia 187.121259 ± 0.000046 °
Mean anomaly 32.730961 ± 0.000041 °
Orbital period 11.66 yr

Ephemeris & Observations

Ephemeris version NIMAv5
Observation file (documentation) omc_ast_NIMAv5.txt
bsp file 1583_Antilochus_nima_v5.bsp
Date of first observation 1926-11-10
Date of last observation 2022-04-14
Number of observations used in the fit 3637
Number of rejected observations 24
Number of DES observations 0
Number of MPC observations 3636
Number of unpublished observations 25
RMS of observations 0.427 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv5 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2022-01 0.019 0.017
2022-07 0.020 0.014
2023-01 0.034 0.023
2023-07 0.028 0.015
2024-01 0.044 0.020
2024-07 0.035 0.013
2025-01 0.046 0.010
2025-07 0.041 0.007
2026-01 0.043 0.007

Ephemeris comparison

residual plot

Difference between NIMAv5 and JPL60 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.