(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 | 39.359739 ± 0.000577 au |
| Eccentricity | 0.221250072 ± 0.000009955 |
| Inclination | 20.587221589 ± 0.000061694 ° |
| Longitude of ascending node | 268.755689 ± 0.000218 ° |
| Argument of perihelia | 72.261921 ± 0.002034 ° |
| Mean anomaly | 178.665565 ± 0.003192 ° |
| Orbital period | 246.94 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv6 |
| Observation file |
omc_ast_NIMAv6.txt |
| bsp file | 90482_Orcus_nima_v6.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2019-05-04 |
| Number of observations used in the fit | 869 |
| Number of rejected observations | 51 |
| Number of DES observations | 0 |
| Number of MPC observations | 538 |
| Number of unpublished observations | 382 |
| RMS of observations | 0.200 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv6 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2019-01 | 0.065 | 0.038 |
| 2019-07 | 0.036 | 0.031 |
| 2020-01 | 0.074 | 0.043 |
| 2020-07 | 0.044 | 0.035 |
| 2021-01 | 0.084 | 0.049 |
| 2021-07 | 0.053 | 0.039 |
| 2022-01 | 0.096 | 0.056 |
| 2022-07 | 0.063 | 0.043 |
| 2023-01 | 0.109 | 0.063 |
Ephemeris comparison
Difference between NIMAv6 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.