(2241) Alcathous
This object has a more recent orbit available here
Object
| Object | (2241) Alcathous |
| Diameter(1) | 115 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) | 2458600.5 |
| Semi major axis | 5.179885 ± 0.000001 au |
| Eccentricity | 0.067236613 ± 0.000000126 |
| Inclination | 16.627526924 ± 0.000006267 ° |
| Longitude of ascending node | 267.998046 ± 0.000023 ° |
| Argument of perihelia | 292.243606 ± 0.000066 ° |
| Mean anomaly | 346.975321 ± 0.000068 ° |
| Orbital period | 11.79 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv2 |
| Observation file |
omc_ast_NIMAv2.txt |
| bsp file | 2241_Alcathous_nima_v2.bsp |
| Date of first observation | 1950-06-19 |
| Date of last observation | 2019-07-28 |
| Number of observations used in the fit | 2262 |
| Number of rejected observations | 8 |
| Number of DES observations | 0 |
| Number of MPC observations | 2270 |
| Number of unpublished observations | 0 |
| RMS of observations | 0.470 arcsec |
Residuals
Residuals in right ascension and declination compared to NIMAv2 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
| date | σα (arcsec) | σδ (arcsec) |
| 2019-01 | 0.028 | 0.023 |
| 2019-07 | 0.028 | 0.023 |
| 2020-01 | 0.035 | 0.022 |
| 2020-07 | 0.045 | 0.028 |
| 2021-01 | 0.042 | 0.022 |
| 2021-07 | 0.062 | 0.033 |
| 2022-01 | 0.044 | 0.025 |
| 2022-07 | 0.065 | 0.039 |
| 2023-01 | 0.045 | 0.027 |
Ephemeris comparison
Difference between NIMAv2 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.