(1208) Troilus


Object

Object (1208) Troilus
Diameter(1) 100 km
Dynamic class(1) trojan
Absolute magnitude 8.99
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2458600.5
Semi major axis 5.252322 ± 0.000000 au
Eccentricity 0.091363682 ± 0.000000075
Inclination 33.540993326 ± 0.000006308 °
Longitude of ascending node 48.547237 ± 0.000007 °
Argument of perihelia 295.613145 ± 0.000059 °
Mean anomaly 222.455300 ± 0.000060 °
Orbital period 12.04 yr

Ephemeris & Observations

Ephemeris version NIMAv3
Observation file (documentation) omc_ast_NIMAv3.txt
bsp file 1208_Troilus_nima_v3.bsp
Date of first observation 1931-12-31
Date of last observation 2021-01-18
Number of observations used in the fit 2716
Number of rejected observations 16
Number of DES observations 0
Number of MPC observations 2730
Number of unpublished observations 2
RMS of observations 3.185 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv3 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2021-01 0.012 0.012
2021-07 0.018 0.020
2022-01 0.020 0.015
2022-07 0.040 0.024
2023-01 0.034 0.021
2023-07 0.046 0.043
2024-01 0.041 0.037
2024-07 0.041 0.051
2025-01 0.043 0.053

Ephemeris comparison

residual plot

Difference between NIMAv3 and JPL56 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