(1871) Astyanax
This object has a more recent orbit available here
Object
Object | (1871) Astyanax |
Diameter(1) | 34 km |
Dynamic class(1) | trojan |
Absolute magnitude | 11.32 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2460600.5 |
Semi major axis | 5.222505 ± 0.000000 au |
Eccentricity | 0.033711045 ± 0.000000055 |
Inclination | 8.610719158 ± 0.000005892 ° |
Longitude of ascending node | 145.764197 ± 0.000044 ° |
Argument of perihelia | 167.116295 ± 0.000116 ° |
Mean anomaly | 19.822851 ± 0.000107 ° |
Orbital period | 11.94 yr |
Ephemeris & Observations
Ephemeris version | NIMAv6 |
Observation file |
omc_ast_NIMAv6.txt |
bsp file | 1871_Astyanax_nima_v6.bsp |
Date of first observation | 1971-03-24 |
Date of last observation | 2024-07-12 |
Number of observations used in the fit | 2442 |
Number of rejected observations | 166 |
Number of DES observations | 20 |
Number of MPC observations | 2560 |
Number of unpublished observations | 28 |
RMS of observations | 0.480 arcsec |
Residuals

Residuals in right ascension and declination compared to NIMAv6 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
date | σα (arcsec) | σδ (arcsec) |
2024-01 | 0.033 | 0.022 |
2024-07 | 0.047 | 0.029 |
2025-01 | 0.037 | 0.021 |
2025-07 | 0.044 | 0.024 |
2026-01 | 0.043 | 0.022 |
2026-07 | 0.044 | 0.021 |
2027-01 | 0.052 | 0.025 |
2027-07 | 0.045 | 0.021 |
2028-01 | 0.062 | 0.030 |
Ephemeris comparison

Difference between NIMAv6 and JPL52 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.