(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 | 39.359694 ± 0.000594 au |
| Eccentricity | 0.221250850 ± 0.000010148 |
| Inclination | 20.587221320 ± 0.000066010 ° |
| Longitude of ascending node | 268.755688 ± 0.000226 ° |
| Argument of perihelia | 72.261752 ± 0.002132 ° |
| Mean anomaly | 178.665824 ± 0.003337 ° |
| Orbital period | 246.94 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv5 |
| Observation file |
omc_ast_NIMAv5.txt |
| bsp file | 90482_Orcus_nima_v5.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2018-05-15 |
| Number of observations used in the fit | 859 |
| Number of rejected observations | 51 |
| Number of DES observations | 0 |
| Number of MPC observations | 538 |
| Number of unpublished observations | 372 |
| RMS of observations | 0.201 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv5 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2018-01 | 0.062 | 0.036 |
| 2018-07 | 0.034 | 0.031 |
| 2019-01 | 0.071 | 0.042 |
| 2019-07 | 0.042 | 0.034 |
| 2020-01 | 0.081 | 0.048 |
| 2020-07 | 0.050 | 0.038 |
| 2021-01 | 0.093 | 0.054 |
| 2021-07 | 0.060 | 0.042 |
| 2022-01 | 0.105 | 0.061 |
Ephemeris comparison
Difference between NIMAv5 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.