(2241) Alcathous
Object
| Object |
(2241) Alcathous |
| Diameter(1) |
115 km |
| Dynamic class(1) |
trojan |
| Absolute magnitude |
8.62 |
| G slop |
0.15 |
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 (documentation) |
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| Number of unpublished observations |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.
Previous NIMA versions