(99943) 2005AS2
This object has a more recent orbit available here
Object
Object | (99943) 2005AS2 |
Diameter(1) | 28 km |
Dynamic class(1) | trojan |
Absolute magnitude | 11.70 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2460600.5 |
Semi major axis | 5.295337 ± 0.000000 au |
Eccentricity | 0.108391298 ± 0.000000020 |
Inclination | 13.532040754 ± 0.000001297 ° |
Longitude of ascending node | 116.238764 ± 0.000003 ° |
Argument of perihelia | 90.306242 ± 0.000014 ° |
Mean anomaly | 159.705504 ± 0.000010 ° |
Orbital period | 12.19 yr |
Ephemeris & Observations
Ephemeris version | NIMAv5 |
Observation file |
omc_ast_NIMAv5.txt |
bsp file | 99943_2005AS2_nima_v5.bsp |
Date of first observation | 1996-06-21 |
Date of last observation | 2023-12-09 |
Number of observations used in the fit | 2059 |
Number of rejected observations | 6 |
Number of DES observations | 38 |
Number of MPC observations | 1726 |
Number of unpublished observations | 2 |
RMS of observations | 0.120 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) |
2024-01 | 0.016 | 0.005 |
2024-07 | 0.022 | 0.009 |
2025-01 | 0.022 | 0.008 |
2025-07 | 0.025 | 0.010 |
2026-01 | 0.028 | 0.012 |
2026-07 | 0.028 | 0.010 |
2027-01 | 0.036 | 0.013 |
2027-07 | 0.031 | 0.008 |
2028-01 | 0.046 | 0.011 |
Ephemeris comparison

Difference between NIMAv5 and JPL41 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.