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: 20WM18 # Created Sun Apr 27 01:11:23 2025 # Orbit generated from Bernstein formalism # Fitting 6 observations of 6 # Arc: 60.90d # First observation: 2020/11/16 # Last observation: 2021/01/16 Preliminary a, adot, b, bdot, g, gdot: -0.000000 0.019360 0.000000 -0.003611 0.020392 0.000000 # WARNING Fitting with energy constraint # Chi-squared of fit: 1.49 DOF: 7 RMS: 0.09 # Min/Max residuals: -0.22 0.16 # Exact a, adot, b, bdot, g, gdot: 1.264174E-05 1.605085E-02 -1.836111E-06 -3.648361E-03 1.987944E-02 -7.084208E-03 # Covariance matrix: 8.4197E-13 5.6502E-11 -8.0907E-15 5.3382E-13 1.0139E-11 -1.0685E-09 5.6502E-11 1.0232E-07 -2.4189E-11 1.6203E-09 1.3636E-08 -2.9900E-06 -8.0907E-15 -2.4189E-11 6.3506E-13 -5.0271E-12 -3.1536E-12 7.3324E-10 5.3382E-13 1.6203E-09 -5.0271E-12 8.2843E-11 2.1115E-10 -4.9148E-08 1.0139E-11 1.3636E-08 -3.1536E-12 2.1115E-10 1.8406E-09 -3.9059E-07 -1.0685E-09 -2.9900E-06 7.3324E-10 -4.9148E-08 -3.9059E-07 9.0357E-05 # lat0 lon0 xBary yBary zBary JD0 -0.095131 46.057420 -0.145052 -0.001653 -0.979635 2459169.666681 # Heliocentric elements and errors Epoch: 2459160.5000 = 2020/11/07 Mean Anomaly: 299.84533 +/- 59.350 Argument of Peri: 286.43993 +/- 25.151 Long of Asc Node: 225.79884 +/- 0.009 Inclination: 12.80362 +/- 0.285 Eccentricity: 0.39300912 +/- 0.4913 Semi-Major Axis: 54.07343348 +/- 26.4204 Time of Perihelion: 2483428.9043 +/- 16029.5 Perihelion: 32.82208100 +/- 31.0292 Aphelion: 75.32478597 +/- 45.3889 Period (y) 397.6346 +/- 291.43 # Ecliptic coordinates at JD0 (AU and AU/d) Ecliptic X 35.48846778 +/- 0.0753 Ecliptic Y 37.02027847 +/- 0.0782 Ecliptic Z -0.08368282 +/- 0.0002 Ecliptic XDOT -0.00226222 +/- 0.0009 Ecliptic YDOT 0.00083623 +/- 0.0009 Ecliptic ZDOT -0.00050106 +/- 0.0000 # Distances at JD0 (AU) Heliocenter to KBO 51.28293446 +/- 0.0768 Geocenter to KBO 50.30322857 +/- 0.1086 # Hcoef: 6.92
The following table shows the complete astrometric record for 20WM18. 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 (20WM18) followed by the observatory code and reference code for the source of the astrometry.
2020 11 16.16588 02 54 28.704 +16 33 08.18 23.8r 20WM18 807 C~5Jzg 2020 11 18.13757 02 54 20.726 +16 32 29.86 24.0r 20WM18 807 C~5Jzg 2020 12 16.22159 02 52 38.863 +16 24 08.47 23.9r 20WM18 304 C~5Jzg 2020 12 17.21196 02 52 35.878 +16 23 53.39 24.0r 20WM18 304 C~5Jzg 2021 01 15.07856 02 51 36.152 +16 18 33.82 20WM18 304 C~5Jzg 2021 01 16.07031 02 51 35.164 +16 18 27.59 20WM18 304 C~5Jzg
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 0.03 0.00 -0.22
2 0.0054 -120.89 -0.03 -3.65 0.16
3 0.0823 -1668.55 -0.04 -59.99 0.08
4 0.0850 -1714.03 0.04 -61.95 0.06
5 0.1640 -2629.56 0.01 -117.75 -0.07
6 0.1667 -2644.98 -0.01 -119.57 -0.00
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.
20WM18 quality flag:0 Type: ERR2LARGE ERR2LARGE ERR2LARGE axisobj 0.000 0.000 0.000 ecceobj -1.000 -1.000 -1.000 incobj -1.000 -1.000 -1.000 qmin 0.000 0.000 0.000 qmax 0.000 0.000 0.000 amean 0.000 0.000 0.000 amin 0.000 0.000 0.000 amax 0.000 0.000 0.000 emean 0.000 0.000 0.000 emin 0.000 0.000 0.000 emax 0.000 0.000 0.000 imean 0.000 0.000 0.000 imin 0.000 0.000 0.000 imax 0.000 0.000 0.000 excite_mean 0.000 0.000 0.000 fracstop 0.000 0.000 0.000 cjmean 0.000 0.000 0.000 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 0.0 0.0 0.0 kozaiamp 0.0 0.0 0.0