(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 ± 0.000001 au
Eccentricity 0.091363730 ± 0.000000100
Inclination 33.540995950 ± 0.000006525 °
Longitude of ascending node 48.547234 ± 0.000011 °
Argument of perihelia 295.613172 ± 0.000063 °
Mean anomaly 222.455271 ± 0.000069 °
Orbital period 12.04 yr

Ephemeris & Observations

Ephemeris version NIMAv2
Observation file (documentation) omc_ast_NIMAv2.txt
bsp file 1208_Troilus_nima_v2.bsp
Date of first observation 1931-12-31
Date of last observation 2019-08-01
Number of observations used in the fit 2279
Number of rejected observations 16
Number of DES observations 0
Number of MPC observations 2295
Number of unpublished observations 0
RMS of observations 0.505 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv2 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2019-01 0.020 0.021
2019-07 0.022 0.024
2020-01 0.025 0.027
2020-07 0.032 0.039
2021-01 0.037 0.033
2021-07 0.055 0.053
2022-01 0.055 0.029
2022-07 0.093 0.032
2023-01 0.069 0.026

Ephemeris comparison

residual plot

Difference between NIMAv2 and JPL41 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