(1583) Antilochus


Object

Object (1583) Antilochus
Diameter(1) 109 km
Dynamic class(1) trojan
Absolute magnitude 8.66
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2460600.5
Semi major axis 5.149053 ± 0.000000 au
Eccentricity 0.053750584 ± 0.000000009
Inclination 28.489614312 ± 0.000000393 °
Longitude of ascending node 221.375452 ± 0.000000 °
Argument of perihelia 188.676962 ± 0.000012 °
Mean anomaly 98.800747 ± 0.000010 °
Orbital period 11.68 yr

Ephemeris & Observations

Ephemeris version NIMAv7
Observation file (documentation) omc_ast_NIMAv7.txt
bsp file 1583_Antilochus_nima_v7.bsp
Date of first observation 1926-11-10
Date of last observation 2024-06-18
Number of observations used in the fit 5507
Number of rejected observations 30
Number of DES observations 0
Number of MPC observations 5172
Number of unpublished observations 25
RMS of observations 0.121 arcsec

Residuals

residual plot

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)
2024-01 0.016 0.005
2024-07 0.013 0.003
2025-01 0.017 0.002
2025-07 0.015 0.002
2026-01 0.017 0.002
2026-07 0.018 0.002
2027-01 0.016 0.004
2027-07 0.019 0.004
2028-01 0.015 0.005

Ephemeris comparison

residual plot

Difference between NIMAv7 and JPL73 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