(2241) Alcathous
This object has a more recent orbit available here
Object
| Object | (2241) Alcathous |
| Diameter(1) | 114 km |
| Dynamic class(1) | trojan |
| Absolute magnitude | 8.64 |
| G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
| Epoch (Julian date) | 2458200.5 |
| Semi major axis | 5.181969 ± 0.000000 au |
| Eccentricity | 0.067374134 ± 0.000000075 |
| Inclination | 16.627094584 ± 0.000005246 ° |
| Longitude of ascending node | 267.992478 ± 0.000015 ° |
| Argument of perihelia | 291.802139 ± 0.000058 ° |
| Mean anomaly | 313.949601 ± 0.000063 ° |
| Orbital period | 11.80 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv1 |
| Observation file |
omc_ast_NIMAv1.txt |
| bsp file | 2241_Alcathous_nima_v1.bsp |
| Date of first observation | 1950-06-19 |
| Date of last observation | 2019-01-28 |
| Number of observations used in the fit | 1974 |
| Number of rejected observations | 15 |
| Number of DES observations | 0 |
| Number of MPC observations | 1989 |
| Number of unpublished observations | 0 |
| RMS of observations | 0.494 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv1 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2018-01 | 0.021 | 0.018 |
| 2018-07 | 0.017 | 0.015 |
| 2019-01 | 0.028 | 0.020 |
| 2019-07 | 0.028 | 0.020 |
| 2020-01 | 0.035 | 0.018 |
| 2020-07 | 0.044 | 0.023 |
| 2021-01 | 0.038 | 0.017 |
| 2021-07 | 0.055 | 0.023 |
| 2022-01 | 0.037 | 0.018 |
Ephemeris comparison
Difference between NIMAv1 and JPL59 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.