(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 | 10.00 |
| G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
| Epoch (Julian date) | 2458600.5 |
| Semi major axis | 5.125316 ± 0.000000 au |
| Eccentricity | 0.036299652 ± 0.000000051 |
| Inclination | 8.468478436 ± 0.000003094 ° |
| Longitude of ascending node | 258.559960 ± 0.000038 ° |
| Argument of perihelia | 179.594245 ± 0.000118 ° |
| Mean anomaly | 238.739987 ± 0.000149 ° |
| Orbital period | 11.60 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv5 |
| Observation file |
omc_ast_NIMAv5.txt |
| bsp file | 21900_Orus_nima_v5.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2021-01-11 |
| Number of observations used in the fit | 2497 |
| Number of rejected observations | 9 |
| Number of DES observations | 14 |
| Number of MPC observations | 2195 |
| Number of unpublished observations | 297 |
| RMS of observations | 0.373 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv5 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2020-01 | 0.007 | 0.007 |
| 2020-07 | 0.016 | 0.013 |
| 2021-01 | 0.017 | 0.015 |
| 2021-07 | 0.027 | 0.019 |
| 2022-01 | 0.033 | 0.025 |
| 2022-07 | 0.037 | 0.020 |
| 2023-01 | 0.054 | 0.027 |
| 2023-07 | 0.043 | 0.018 |
| 2024-01 | 0.068 | 0.026 |
Ephemeris comparison
Difference between NIMAv5 and JPL26 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.