(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 | 39.359518 ± 0.000471 au |
| Eccentricity | 0.221253934 ± 0.000008374 |
| Inclination | 20.587213637 ± 0.000047847 ° |
| Longitude of ascending node | 268.755648 ± 0.000198 ° |
| Argument of perihelia | 72.261184 ± 0.001635 ° |
| Mean anomaly | 178.666750 ± 0.002554 ° |
| Orbital period | 246.94 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv7 |
| Observation file |
omc_ast_NIMAv7.txt |
| bsp file | 90482_Orcus_nima_v7.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2020-05-25 |
| Number of observations used in the fit | 1309 |
| Number of rejected observations | 52 |
| Number of DES observations | 0 |
| Number of MPC observations | 963 |
| Number of unpublished observations | 398 |
| RMS of observations | 0.258 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) |
| 2020-01 | 0.051 | 0.032 |
| 2020-07 | 0.031 | 0.028 |
| 2021-01 | 0.058 | 0.037 |
| 2021-07 | 0.036 | 0.031 |
| 2022-01 | 0.067 | 0.042 |
| 2022-07 | 0.043 | 0.034 |
| 2023-01 | 0.076 | 0.047 |
| 2023-07 | 0.051 | 0.038 |
| 2024-01 | 0.086 | 0.053 |
Ephemeris comparison
Difference between NIMAv7 and JPL29 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.