(90482) Orcus
This object has a more recent orbit available here
Object
| Object | (90482) Orcus |
| Diameter(1) | 910 km |
| Dynamic class(1) | plutino |
| Absolute magnitude | 2.20 |
| G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
| Epoch (Julian date) | 2458200.5 |
| Semi major axis | 39.359462 ± 0.000466 au |
| Eccentricity | 0.221255025 ± 0.000008302 |
| Inclination | 20.587213496 ± 0.000046070 ° |
| Longitude of ascending node | 268.755644 ± 0.000190 ° |
| Argument of perihelia | 72.261020 ± 0.001594 ° |
| Mean anomaly | 178.667002 ± 0.002493 ° |
| Orbital period | 246.93 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv8 |
| Observation file |
omc_ast_NIMAv8.txt |
| bsp file | 90482_Orcus_nima_v8.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2021-06-17 |
| Number of observations used in the fit | 1367 |
| Number of rejected observations | 14 |
| Number of DES observations | 0 |
| Number of MPC observations | 963 |
| Number of unpublished observations | 418 |
| RMS of observations | 0.256 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv8 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2021-01 | 0.055 | 0.035 |
| 2021-07 | 0.033 | 0.029 |
| 2022-01 | 0.062 | 0.039 |
| 2022-07 | 0.039 | 0.032 |
| 2023-01 | 0.071 | 0.044 |
| 2023-07 | 0.046 | 0.035 |
| 2024-01 | 0.081 | 0.050 |
| 2024-07 | 0.055 | 0.039 |
| 2025-01 | 0.092 | 0.055 |
Ephemeris comparison
Difference between NIMAv8 and JPL40 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.