(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 | 8.62 |
| G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
| Epoch (Julian date) | 2456657.921471629 |
| Semi major axis | 5.192262 ± 0.000000 au |
| Eccentricity | 0.065873673 ± 0.000000009 |
| Inclination | 16.612971736 ± 0.000000292 ° |
| Longitude of ascending node | 267.997344 ± 0.000000 ° |
| Argument of perihelia | 290.748493 ± 0.000010 ° |
| Mean anomaly | 186.182274 ± 0.000012 ° |
| Orbital period | 11.83 yr |
Ephemeris & Observations
| Ephemeris version | NIMAv5 |
| Observation file |
omc_ast_NIMAv5.txt |
| bsp file | 2241_Alcathous_nima_v5.bsp |
| Date of first observation | 1950-06-19 |
| Date of last observation | 2023-07-26 |
| Number of observations used in the fit | 4590 |
| Number of rejected observations | 25 |
| Number of DES observations | 0 |
| Number of MPC observations | 4011 |
| Number of unpublished observations | 355 |
| RMS of observations | 0.132 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) |
| 2023-01 | 0.003 | 0.002 |
| 2023-07 | 0.006 | 0.003 |
| 2024-01 | 0.005 | 0.003 |
| 2024-07 | 0.009 | 0.004 |
| 2025-01 | 0.008 | 0.004 |
| 2025-07 | 0.011 | 0.003 |
| 2026-01 | 0.012 | 0.004 |
| 2026-07 | 0.013 | 0.001 |
| 2027-01 | 0.016 | 0.001 |
Ephemeris comparison
Difference between NIMAv5 and JPL79 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.