Orbit Fit and Astrometric record for 98WX31

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: 98WX31    
# Created Fri Dec 15 02:36:55 2017
# Orbit generated from Bernstein formalism
# Fitting   23 observations of   23
# Arc:   9.29y
# First observation: 1998/11/18
#  Last observation: 2008/03/04
Preliminary a, adot, b, bdot, g, gdot:
   0.000098   0.025975   0.000004   0.001161   0.025068   0.000000
# Chi-squared of fit:    97.39 DOF:   40 RMS:  0.36
# Min/Max residuals:    -1.98    0.50
# Exact a, adot, b, bdot, g, gdot:
  1.616106E-05  2.607631E-02  1.623065E-06  1.163999E-03  2.518857E-02 -3.859387E-04
# Covariance matrix:
  3.8409E-13 -2.1098E-13  9.2269E-15 -9.0736E-15  1.7256E-13 -9.8722E-13
 -2.1098E-13  1.7534E-13 -7.9776E-15  8.0286E-15 -6.0253E-14  8.4204E-13
  9.2269E-15 -7.9776E-15  1.2834E-13 -2.1889E-14  3.4400E-15 -4.0168E-14
 -9.0736E-15  8.0286E-15 -2.1889E-14  7.6033E-15 -2.9407E-15  4.0234E-14
  1.7256E-13 -6.0253E-14  3.4400E-15 -2.9407E-15  2.7867E-13 -3.9582E-13
 -9.8722E-13  8.4204E-13 -4.0168E-14  4.0234E-14 -3.9582E-13  4.2517E-12
#      lat0       lon0       xBary       yBary       zBary        JD0
    1.541782   68.185386    0.202669    0.025694   -0.963038  2451135.917141
# Heliocentric elements and errors
Epoch:              2451130.5000  =  1998/11/13
Mean Anomaly:          352.14836 +/-     0.039
Argument of Peri:       40.35627 +/-     0.050
Long of Asc Node:       37.40330 +/-     0.002
Inclination:             2.96504 +/-     0.000
Eccentricity:         0.11074922 +/-    0.0001
Semi-Major Axis:     45.66427658 +/-    0.0052
Time of Perihelion: 2453588.7230 +/-      12.3
Perihelion:          40.60699360 +/-    0.0058
Aphelion:            50.72155955 +/-    0.0067
Period (y)              308.5838 +/-      0.05
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X           15.30150875 +/-    0.0003
Ecliptic Y           37.66291688 +/-    0.0008
Ecliptic Z            1.06824986 +/-    0.0000
Ecliptic XDOT        -0.00264882 +/-    0.0000
Ecliptic YDOT         0.00102027 +/-    0.0000
Ecliptic ZDOT         0.00012532 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   40.66660344 +/-    0.0007
Geocenter to KBO     39.70054987 +/-    0.0008
# Hcoef:  6.61

The following table shows the complete astrometric record for 98WX31. 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 (98WX31) followed by the observatory code and reference code for the source of the astrometry.

1998 11  18.41641  04 24 39.16   +23 11 38.2   22.1R 98WX31    695  Ca3608      
1998 11  18.48756  04 24 38.78   +23 11 37.3         98WX31    695  Ca3608      
1999 01  15.18020  04 19 59.34   +23 00 51.2   22.2R 98WX31    695  Ca3608      
1999 01  15.28043  04 19 59.00   +23 00 50.4         98WX31    695  Ca3608      
1999 12  28.20885  04 27 34.68   +23 22 20.9   22.5R 98WX31    695  Ca9916      
1999 12  28.21610  04 27 34.65   +23 22 21.3   22.1R 98WX31    695  Ca9916      
1999 12  31.27627  04 27 20.45   +23 21 48.4   22.3R 98WX31    695  Ca9916      
1999 12  31.28462  04 27 20.42   +23 21 48.6   22.1R 98WX31    695  Ca9916      
2000 01  05.15228  04 26 59.04   +23 20 58.5   22.6R 98WX31    697  Ca9916      
2000 01  05.21591  04 26 58.60   +23 20 57.5   22.8R 98WX31    697  Ca9916      
2000 01  05.37209  04 26 58.08   +23 20 56.3   22.4R 98WX31    697  Ca9916      
2000 11  23.45582  04 37 00.04   +23 45 39.4   22.0R 98WX31    695  Cc2190      
2000 11  23.50006  04 36 59.79   +23 45 39.2         98WX31    695  Cc2190      
2000 11  28.37346  04 36 33.30   +23 44 51.7   22.4R 98WX31    695  Cc2190      
2000 11  28.41427  04 36 33.07   +23 44 51.3   22.5R 98WX31    695  Cc2190      
2000 11  29.35248  04 36 27.95   +23 44 41.9   22.3R 98WX31    695  Cc2190      
2003 10  01.57487  04 59 49.52   +24 33 25.8   22.5R 98WX31    568  Ci6852      
2003 10  02.53911  04 59 48.13   +24 33 27.3         98WX31    568  Ci6852      
2006 01  31.256962 05 04 03.36   +24 48 13.6   22.6V 98WX31    645  C~1cF1      
2006 01  31.257791 05 04 03.36   +24 48 13.6   22.4V 98WX31    645  C~1cF1      
2006 01  31.260279 05 04 03.35   +24 48 13.6   23.8V 98WX31    645  C~1cF1      
2008 03  03.15613  05 16 15.49   +25 08 16.1         98WX31    695  Cy7583      
2008 03  04.17287  05 16 15.71   +25 08 13.8         98WX31    695  Cy7583      

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     0.04       0.00    -0.18
  2   0.0002     -5.32     0.05      -0.05    -0.30
  3   0.1581  -3914.95     0.31      -2.08    -0.00
  4   0.1584  -3919.71     0.32      -2.08     0.11
  5   1.1083   2489.76     0.06     251.71    -0.41
  6   1.1083   2489.42     0.20     252.17     0.05
  7   1.1167   2291.12     0.08     250.18    -0.12
  8   1.1167   2290.74     0.25     250.44     0.15
  9   1.1300   1992.08     0.33     247.05     0.42
 10   1.1302   1985.94    -1.98     247.01     0.42
 11   1.1306   1978.68     0.14     246.95     0.50
 12   2.0152  10392.74     0.04     486.83    -0.11
 13   2.0153  10389.31    -0.05     487.11     0.15
 14   2.0286  10021.65    -0.00     490.97    -0.05
 15   2.0287  10018.46    -0.05     491.02    -0.03
 16   2.0313   9947.37     0.06     491.58    -0.11
 17   4.8683  29533.27    -0.25    1099.53    -0.55
 18   4.8710  29514.17     0.23    1102.93    -0.15
 19   7.2028  33143.75     0.18    1662.03    -0.08
 20   7.2029  33143.75     0.22    1662.03    -0.08
 21   7.2029  33143.62     0.18    1662.04    -0.06
 22   9.2888  43511.81    -0.19    2078.12     0.15
 23   9.2916  43514.75    -0.15    2075.57     0.30

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.

98WX31    quality flag:3

Type:      CLASSICAL CLASSICAL CLASSICAL

axisobj        45.823    45.839    45.807
ecceobj         0.114     0.114     0.114
incobj          2.966     2.966     2.966
qmin           39.750    39.539    39.536
qmax           51.566    51.735    51.707
amean          45.492    45.508    45.488
amin           45.100    45.118    45.103
amax           45.903    45.929    45.918
emean           0.111     0.113     0.112
emin            0.098     0.098     0.099
emax            0.123     0.128     0.127
imean           2.387     2.477     2.400
imin            1.793     1.899     1.830
imax            2.892     3.004     2.893
excite_mean     0.119     0.121     0.120
fracstop        1.000     1.000     1.000
cjmean          3.102     3.102     3.102

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       173.3     177.5     174.8
kozaiamp        180.0     179.9     180.0