(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 | 39.430485 ± 0.000471 au |
| Eccentricity | 0.219437648 ± 0.000008979 |
| Inclination | 20.546219935 ± 0.000018087 ° |
| Longitude of ascending node | 268.440290 ± 0.000125 ° |
| Argument of perihelia | 73.612098 ± 0.001498 ° |
| Mean anomaly | 171.187693 ± 0.002150 ° |
| Orbital period | 247.60 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv9 |
| Observation file |
omc_ast_NIMAv9.txt |
| bsp file | 90482_Orcus_nima_v9.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2022-05-06 |
| Number of observations used in the fit | 1679 |
| Number of rejected observations | 15 |
| Number of DES observations | 0 |
| Number of MPC observations | 1259 |
| Number of unpublished observations | 435 |
| RMS of observations | 0.291 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv9 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2022-01 | 0.048 | 0.031 |
| 2022-07 | 0.030 | 0.027 |
| 2023-01 | 0.055 | 0.035 |
| 2023-07 | 0.035 | 0.029 |
| 2024-01 | 0.063 | 0.040 |
| 2024-07 | 0.041 | 0.032 |
| 2025-01 | 0.071 | 0.044 |
| 2025-07 | 0.048 | 0.036 |
| 2026-01 | 0.081 | 0.049 |
Ephemeris comparison
Difference between NIMAv9 and JPL43 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.