(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 | 2.26 |
| G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
| Epoch (Julian date) | 2460800.5 |
| Semi major axis | 39.289097 ± 0.000061 au |
| Eccentricity | 0.223145122 ± 0.000001256 |
| Inclination | 20.555534959 ± 0.000005251 ° |
| Longitude of ascending node | 268.386022 ± 0.000044 ° |
| Argument of perihelia | 73.797973 ± 0.000566 ° |
| Mean anomaly | 187.216083 ± 0.000869 ° |
| Orbital period | 246.27 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv11 |
| Observation file |
omc_ast_NIMAv11.txt |
| bsp file | 90482_Orcus_nima_v11.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2025-06-25 |
| Number of observations used in the fit | 2598 |
| Number of rejected observations | 16 |
| Number of DES observations | 0 |
| Number of MPC observations | 1574 |
| Number of unpublished observations | 447 |
| RMS of observations | 0.102 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv11 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2024-01 | 0.011 | 0.008 |
| 2024-07 | 0.010 | 0.007 |
| 2025-01 | 0.014 | 0.009 |
| 2025-07 | 0.012 | 0.008 |
| 2026-01 | 0.016 | 0.011 |
| 2026-07 | 0.015 | 0.010 |
| 2027-01 | 0.019 | 0.013 |
| 2027-07 | 0.017 | 0.011 |
| 2028-01 | 0.023 | 0.015 |
Ephemeris comparison
Difference between NIMAv11 and JPL56 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.