(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 | 0.036299650 ± 0.000000052 |
| Inclination | 8.468475692 ± 0.000003799 ° |
| Longitude of ascending node | 258.559932 ± 0.000045 ° |
| Argument of perihelia | 179.594235 ± 0.000146 ° |
| Mean anomaly | 238.740026 ± 0.000181 ° |
| Orbital period | 11.60 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv4 |
| Observation file |
omc_ast_NIMAv4.txt |
| bsp file | 21900_Orus_nima_v4.bsp |
| Date of first observation | 1951-11-08 |
| Date of last observation | 2020-08-03 |
| Number of observations used in the fit | 1867 |
| Number of rejected observations | 9 |
| Number of DES observations | 14 |
| Number of MPC observations | 1861 |
| Number of unpublished observations | 1 |
| RMS of observations | 0.426 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv4 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2020-01 | 0.008 | 0.008 |
| 2020-07 | 0.021 | 0.016 |
| 2021-01 | 0.022 | 0.019 |
| 2021-07 | 0.036 | 0.024 |
| 2022-01 | 0.043 | 0.030 |
| 2022-07 | 0.046 | 0.024 |
| 2023-01 | 0.067 | 0.032 |
| 2023-07 | 0.051 | 0.021 |
| 2024-01 | 0.078 | 0.030 |
Ephemeris comparison
Difference between NIMAv4 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.