(21900) Orus
This object has a more recent orbit available here
Object
| Object | (21900) Orus |
| Diameter(1) | 59 km |
| Dynamic class(1) | trojan |
| Absolute magnitude | 10.10 |
| G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
| Epoch (Julian date) | 2460600.5 |
| Semi major axis | 5.123563 ± 0.000000 au |
| Eccentricity | 0.037486590 ± 0.000000016 |
| Inclination | 8.468723941 ± 0.000000588 ° |
| Longitude of ascending node | 258.553875 ± 0.000005 ° |
| Argument of perihelia | 182.440511 ± 0.000016 ° |
| Mean anomaly | 46.181145 ± 0.000015 ° |
| Orbital period | 11.60 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv10 |
| Observation file |
omc_ast_NIMAv10.txt |
| bsp file | 21900_Orus_nima_v10.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2024-05-08 |
| Number of observations used in the fit | 4464 |
| Number of rejected observations | 20 |
| Number of DES observations | 14 |
| Number of MPC observations | 4050 |
| Number of unpublished observations | 300 |
| RMS of observations | 0.103 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) |
| 2024-01 | 0.010 | 0.005 |
| 2024-07 | 0.008 | 0.004 |
| 2025-01 | 0.014 | 0.007 |
| 2025-07 | 0.011 | 0.005 |
| 2026-01 | 0.016 | 0.007 |
| 2026-07 | 0.015 | 0.006 |
| 2027-01 | 0.017 | 0.005 |
| 2027-07 | 0.018 | 0.006 |
| 2028-01 | 0.016 | 0.002 |
Ephemeris comparison
Difference between NIMAv10 and JPL37 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.