(21900) Orus
Object
| Object |
(21900) Orus |
| Diameter(1) |
59 km |
| Dynamic class(1) |
trojan |
| Absolute magnitude |
10.10 |
| G slop |
0.15 |
Orbital elements
| Epoch (Julian date) |
2460800.5 |
| Semi major axis |
5.123483 ± 0.000000 au |
| Eccentricity |
0.037236124 ± 0.000000015 |
| Inclination |
8.468660164 ± 0.000000587 ° |
| Longitude of ascending node |
258.553555 ± 0.000005 ° |
| Argument of perihelia |
182.682424 ± 0.000016 ° |
| Mean anomaly |
62.970568 ± 0.000015 ° |
| Orbital period |
11.60 yr |
Ephemeris & Observations
| Ephemeris version |
NIMAv11 |
| Observation file (documentation) |
omc_ast_NIMAv11.txt |
| bsp file |
21900_Orus_nima_v11.bsp |
| Date of first observation |
1951-11-08 |
| Date of last observation |
2025-06-24 |
| Number of observations used in the fit |
5056 |
| Number of rejected observations |
20 |
| Number of DES observations |
14 |
| Number of MPC observations |
4642 |
| Number of unpublished observations |
300 |
| RMS of observations |
0.103 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 |
0.009 |
0.005 |
| 2024-07 |
0.008 |
0.003 |
| 2025-01 |
0.014 |
0.006 |
| 2025-07 |
0.011 |
0.005 |
| 2026-01 |
0.016 |
0.006 |
| 2026-07 |
0.014 |
0.006 |
| 2027-01 |
0.016 |
0.005 |
| 2027-07 |
0.018 |
0.006 |
| 2028-01 |
0.016 |
0.002 |
Ephemeris comparison
Difference between NIMAv11 and JPL40 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