(9142) Rhesus
This object has a more recent orbit available here
Object
Object | (9142) Rhesus |
Diameter(1) | 45 km |
Dynamic class(1) | trojan |
Absolute magnitude | 10.75 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2460600.5 |
Semi major axis | 5.156625 ± 0.000000 au |
Eccentricity | 0.130288445 ± 0.000000047 |
Inclination | 12.809575790 ± 0.000003929 ° |
Longitude of ascending node | 141.198624 ± 0.000026 ° |
Argument of perihelia | 174.150684 ± 0.000035 ° |
Mean anomaly | 40.124981 ± 0.000025 ° |
Orbital period | 11.71 yr |
Ephemeris & Observations
Ephemeris version | NIMAv7 |
Observation file |
omc_ast_NIMAv7.txt |
bsp file | 9142_Rhesus_nima_v7.bsp |
Date of first observation | 1954-12-22 |
Date of last observation | 2024-07-12 |
Number of observations used in the fit | 3191 |
Number of rejected observations | 252 |
Number of DES observations | 5 |
Number of MPC observations | 3435 |
Number of unpublished observations | 3 |
RMS of observations | 0.445 arcsec |
Residuals

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 | 0.035 | 0.015 |
2024-07 | 0.043 | 0.016 |
2025-01 | 0.041 | 0.012 |
2025-07 | 0.040 | 0.013 |
2026-01 | 0.048 | 0.019 |
2026-07 | 0.038 | 0.017 |
2027-01 | 0.052 | 0.026 |
2027-07 | 0.037 | 0.020 |
2028-01 | 0.050 | 0.029 |
Ephemeris comparison

Difference between NIMAv7 and JPL55 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.