The following information shows the result of the orbit fit based on Gary Bernstein's method. Most of the information should be self-explanatory. Take special note that while the original Bernstein software works with barycentric coordinates, we convert these results into a heliocentric coordinate system.
# Object: 18AZ18 # Created Tue Apr 1 01:11:09 2025 # Orbit generated from Bernstein formalism # Fitting 7 observations of 7 # Arc: 1.87y # First observation: 2018/01/15 # Last observation: 2019/11/30 Preliminary a, adot, b, bdot, g, gdot: -0.000001 0.010571 0.000000 -0.001160 0.015374 0.000000 # Chi-squared of fit: 1.81 DOF: 8 RMS: 0.09 # Min/Max residuals: -0.22 0.13 # Exact a, adot, b, bdot, g, gdot: 1.038067E-05 1.045153E-02 -6.948599E-07 -1.150967E-03 1.542652E-02 -2.173016E-03 # Covariance matrix: 7.7588E-13 -7.0395E-12 -1.3736E-15 4.2505E-13 5.4874E-12 -1.3453E-10 -7.0395E-12 7.7093E-10 -1.4444E-12 -4.7028E-11 -7.4527E-10 1.4131E-08 -1.3736E-15 -1.4444E-12 5.6860E-13 -2.9924E-13 1.4824E-12 -2.5363E-11 4.2505E-13 -4.7028E-11 -2.9924E-13 3.2903E-12 4.5371E-11 -8.6403E-10 5.4874E-12 -7.4527E-10 1.4824E-12 4.5371E-11 7.2671E-10 -1.3591E-08 -1.3453E-10 1.4131E-08 -2.5363E-11 -8.6403E-10 -1.3591E-08 2.6018E-07 # lat0 lon0 xBary yBary zBary JD0 -14.961666 84.086445 -0.504529 -0.219354 -0.821437 2458133.974801 # Heliocentric elements and errors Epoch: 2458130.5000 = 2018/01/12 Mean Anomaly: 235.37898 +/- 5.487 Argument of Peri: 33.79122 +/- 5.320 Long of Asc Node: 197.54771 +/- 0.018 Inclination: 15.98446 +/- 0.002 Eccentricity: 0.27790420 +/- 0.0265 Semi-Major Axis: 54.74702893 +/- 0.2530 Time of Perihelion: 2509349.1412 +/- 2226.8 Perihelion: 39.53259973 +/- 1.4621 Aphelion: 69.96145812 +/- 1.4862 Period (y) 405.0877 +/- 2.81 # Ecliptic coordinates at JD0 (AU and AU/d) Ecliptic X 6.03557180 +/- 0.0113 Ecliptic Y 63.18411048 +/- 0.1089 Ecliptic Z -16.73572396 +/- 0.0292 Ecliptic XDOT -0.00188290 +/- 0.0000 Ecliptic YDOT -0.00023687 +/- 0.0001 Ecliptic ZDOT -0.00009792 +/- 0.0000 # Distances at JD0 (AU) Heliocenter to KBO 65.64102681 +/- 0.1050 Geocenter to KBO 64.82343691 +/- 0.1133 # Hcoef: 7.67
The following table shows the complete astrometric record for 18AZ18. The first three columns show the date of observation. The next six columns are RA and DEC. The next column (when provided) is the observed magnitude and filter. The next column is the object name (18AZ18) followed by the observatory code and reference code for the source of the astrometry.
2018 01 15.47400 05 36 54.253 +08 21 33.04 25.6R 18AZ18 568 C~31M1 2018 01 16.47556 05 36 51.412 +08 21 38.33 25.6R 18AZ18 568 C~31M1 2018 12 10.21903 05 41 17.574 +08 18 42.72 25.7r 18AZ18 304 C~31M1 2018 12 10.27046 05 41 17.390 +08 18 42.52 25.7r 18AZ18 304 C~31M1 2018 12 12.23106 05 41 10.865 +08 18 34.79 25.8r 18AZ18 304 C~31M1 2019 11 29.29731 05 44 20.391 +08 17 04.76 25.7r 18AZ18 304 C~3d0D 2019 11 30.27743 05 44 17.301 +08 16 58.31 25.6r 18AZ18 304 C~3d0D
The following table shows the residuals to the orbit fit. The first coumn is the point number. The second column is the time, in years, measured from the first observation. The third and fifth columns are the regularized positions used in the orbit fit. The fourth and sixth columns are the residuals, in arc seconds, for RA and Dec respectively.
1 0.0000 0.00 0.07 0.00 -0.10
2 0.0027 -41.91 -0.07 7.03 0.13
3 0.9001 3898.60 0.05 -326.68 0.07
4 0.9002 3895.87 -0.10 -326.77 0.09
5 0.9056 3798.76 0.04 -330.75 -0.22
6 1.8695 6608.33 -0.00 -526.98 0.04
7 1.8722 6562.22 0.01 -531.74 -0.01
The following table comes from a 10My integration of the orbit of the object. Three columns are shown. The first column is the result of integrating the nominal orbit. The other two columns are based on clones of the nominal orbit that are +/- 3 sigma from the nominal orbit. If all three types agree then the classificiation is deemed secure. The basis for these calculations is described in more detail in AJ, 129, 1117 (2005). Any use made of these calculations should refer to and credit this publication and the Deep Ecliptic Survey Team.
18AZ18 quality flag:3 Type: SCATNEAR SCATNEAR SCATNEAR axisobj 55.189 56.553 54.912 ecceobj 0.267 0.353 0.241 incobj 15.919 15.912 15.923 qmin 38.895 34.882 40.279 qmax 71.941 78.871 69.810 amean 55.017 56.218 54.713 amin 54.460 55.400 54.190 amax 55.680 57.324 55.353 emean 0.277 0.360 0.250 emin 0.264 0.343 0.238 emax 0.292 0.377 0.262 imean 15.874 15.635 15.982 imin 15.411 14.779 15.647 imax 16.310 16.290 16.305 excite_mean 0.389 0.450 0.372 fracstop 1.000 1.000 1.000 cjmean 3.046 2.990 3.060 libcent 0 -180.0 -180.0 -180.0 libamp 0 -180.0 -180.0 -180.0 libcent 1 -180.0 -180.0 -180.0 libamp 1 -180.0 -180.0 -180.0 libcent 2 -180.0 -180.0 -180.0 libamp 2 -180.0 -180.0 -180.0 libcent 3 -180.0 -180.0 -180.0 libamp 3 -180.0 -180.0 -180.0 libcent 4 -180.0 -180.0 -180.0 libamp 4 -180.0 -180.0 -180.0 kozaimean 167.8 163.8 175.1 kozaiamp 179.9 179.9 180.0