(1583) Antilochus


Object

Object (1583) Antilochus
Diameter(1) 109 km
Dynamic class(1) trojan
Absolute magnitude 8.60
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2458600.5
Semi major axis 5.132436 ± 0.000000 au
Eccentricity 0.052111575 ± 0.000000064
Inclination 28.511857784 ± 0.000003718 °
Longitude of ascending node 221.376450 ± 0.000006 °
Argument of perihelia 186.805852 ± 0.000060 °
Mean anomaly 291.368282 ± 0.000063 °
Orbital period 11.63 yr

Ephemeris & Observations

Ephemeris version NIMAv4
Observation file (documentation) omc_ast_NIMAv4.txt
bsp file 1583_Antilochus_nima_v4.bsp
Date of first observation 1926-11-10
Date of last observation 2020-09-09
Number of observations used in the fit 2615
Number of rejected observations 19
Number of DES observations 0
Number of MPC observations 2609
Number of unpublished observations 25
RMS of observations 0.504 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)
2020-01 0.007 0.006
2020-07 0.007 0.006
2021-01 0.009 0.010
2021-07 0.014 0.011
2022-01 0.021 0.019
2022-07 0.022 0.015
2023-01 0.037 0.024
2023-07 0.030 0.016
2024-01 0.047 0.021

Ephemeris comparison

residual plot

Difference between NIMAv4 and JPL34 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