Orbit Fit and Astrometric record for 20WM18

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 Tue Apr  1 01:11:22 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