(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 | 4.80 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2458600.5 |
Semi major axis | 45.462656 ± 0.005590 au |
Eccentricity | 0.098648098 ± 0.000073579 |
Inclination | 12.057034302 ± 0.000912179 ° |
Longitude of ascending node | 50.042734 ± 0.001343 ° |
Argument of perihelia | 58.482184 ± 0.030301 ° |
Mean anomaly | 340.755787 ± 0.028730 ° |
Orbital period | 306.54 yr |
Ephemeris & Observations
Ephemeris version | NIMAv4 |
Observation file |
omc_ast_NIMAv4.txt |
bsp file | 19521_Chaos_nima_v4.bsp |
Date of first observation | 1991-10-17 |
Date of last observation | 2019-11-30 |
Number of observations used in the fit | 185 |
Number of rejected observations | 1 |
Number of DES observations | 0 |
Number of MPC observations | 112 |
Number of unpublished observations | 74 |
RMS of observations | 0.393 arcsec |
Residuals

Residuals in right ascension and declination compared to NIMAv4 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
date | σα (arcsec) | σδ (arcsec) |
2019-01 | 0.116 | 0.098 |
2019-07 | 0.165 | 0.099 |
2020-01 | 0.151 | 0.106 |
2020-07 | 0.211 | 0.105 |
2021-01 | 0.199 | 0.115 |
2021-07 | 0.265 | 0.111 |
2022-01 | 0.257 | 0.124 |
2022-07 | 0.328 | 0.118 |
2023-01 | 0.326 | 0.133 |
Ephemeris comparison

Difference between NIMAv4 and JPL12 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.