(90482) Orcus
Object
| Object |
(90482) Orcus |
| Diameter(1) |
910 km |
| Dynamic class(1) |
plutino |
| Absolute magnitude |
2.26 |
| G slop |
0.15 |
Orbital elements
| Epoch (Julian date) |
2460800.5 |
| Semi major axis |
39.288978 ± 0.000061 au |
| Eccentricity |
0.223146340 ± 0.000001255 |
| Inclination |
20.555550965 ± 0.000005176 ° |
| Longitude of ascending node |
268.386134 ± 0.000043 ° |
| Argument of perihelia |
73.796622 ± 0.000544 ° |
| Mean anomaly |
187.218035 ± 0.000836 ° |
| Orbital period |
246.27 yr |
Ephemeris & Observations
| Ephemeris version |
NIMAv12 |
| Observation file (documentation) |
omc_ast_NIMAv12.txt |
| bsp file |
90482_Orcus_nima_v12.bsp |
| Date of first observation |
1951-11-08 |
| Date of last observation |
2025-11-14 |
| Number of observations used in the fit |
2601 |
| Number of rejected observations |
19 |
| Number of DES observations |
0 |
| Number of MPC observations |
1574 |
| Number of unpublished observations |
453 |
| RMS of observations |
0.098 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv12 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 |
0.013 |
0.009 |
| 2025-07 |
0.012 |
0.008 |
| 2026-01 |
0.015 |
0.011 |
| 2026-07 |
0.014 |
0.010 |
| 2027-01 |
0.018 |
0.012 |
| 2027-07 |
0.017 |
0.011 |
| 2028-01 |
0.022 |
0.014 |
Ephemeris comparison
Difference between NIMAv12 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.
Previous NIMA versions