(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 | 2.29 |
| G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
| Epoch (Julian date) | 2456725.202477707 |
| Semi major axis | 39.430554 ± 0.000456 au |
| Eccentricity | 0.219436406 ± 0.000008734 |
| Inclination | 20.546219340 ± 0.000016731 ° |
| Longitude of ascending node | 268.440286 ± 0.000118 ° |
| Argument of perihelia | 73.612329 ± 0.001422 ° |
| Mean anomaly | 171.187368 ± 0.002039 ° |
| Orbital period | 247.60 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv10 |
| Observation file |
omc_ast_NIMAv10.txt |
| bsp file | 90482_Orcus_nima_v10.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2023-05-28 |
| Number of observations used in the fit | 1739 |
| Number of rejected observations | 15 |
| Number of DES observations | 0 |
| Number of MPC observations | 1307 |
| Number of unpublished observations | 447 |
| RMS of observations | 0.297 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv10 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2023-01 | 0.049 | 0.032 |
| 2023-07 | 0.031 | 0.027 |
| 2024-01 | 0.056 | 0.036 |
| 2024-07 | 0.036 | 0.030 |
| 2025-01 | 0.064 | 0.040 |
| 2025-07 | 0.043 | 0.033 |
| 2026-01 | 0.073 | 0.045 |
| 2026-07 | 0.050 | 0.036 |
| 2027-01 | 0.083 | 0.050 |
Ephemeris comparison
Difference between NIMAv10 and JPL48 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.