(19521) Chaos
This object has a more recent orbit available here
Object
Object | (19521) Chaos |
Diameter(1) | 600 km |
Dynamic class(1) | cubewano |
Absolute magnitude | 4.64 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2459800.5 |
Semi major axis | 45.758134 ± 0.000261 au |
Eccentricity | 0.103211965 ± 0.000003675 |
Inclination | 12.018379276 ± 0.000022881 ° |
Longitude of ascending node | 49.899997 ± 0.000091 ° |
Argument of perihelia | 55.647919 ± 0.001727 ° |
Mean anomaly | 347.188446 ± 0.001449 ° |
Orbital period | 309.54 yr |
Ephemeris & Observations
Ephemeris version | NIMAv11 |
Observation file |
omc_ast_NIMAv11.txt |
bsp file | 19521_Chaos_nima_v11.bsp |
Date of first observation | 1991-10-17 |
Date of last observation | 2023-03-29 |
Number of observations used in the fit | 262 |
Number of rejected observations | 13 |
Number of DES observations | 0 |
Number of MPC observations | 167 |
Number of unpublished observations | 108 |
RMS of observations | 0.291 arcsec |
Residuals

Residuals in right ascension and declination compared to NIMAv11 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
date | σα (arcsec) | σδ (arcsec) |
2023-01 | 0.004 | 0.003 |
2023-07 | 0.008 | 0.004 |
2024-01 | 0.009 | 0.005 |
2024-07 | 0.012 | 0.006 |
2025-01 | 0.014 | 0.007 |
2025-07 | 0.018 | 0.008 |
2026-01 | 0.020 | 0.010 |
2026-07 | 0.024 | 0.011 |
2027-01 | 0.027 | 0.013 |
Ephemeris comparison

Difference between NIMAv11 and JPL16 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.