Orbit Fit and Astrometric record for 02GW31

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: 02GW31    
# Created Sun Oct 22 01:37:18 2017
# Orbit generated from Bernstein formalism
# Fitting   19 observations of   19
# Arc:  10.93y
# First observation: 2002/04/06
#  Last observation: 2013/03/12
Preliminary a, adot, b, bdot, g, gdot:
   0.000561   0.023428   0.000011   0.000637   0.025750   0.000000
# Chi-squared of fit:    40.40 DOF:   32 RMS:  0.26
# Min/Max residuals:    -0.61    0.38
# Exact a, adot, b, bdot, g, gdot:
  1.616345E-05  2.440615E-02  3.306139E-07  6.635722E-04  2.552887E-02  5.833203E-03
# Covariance matrix:
  2.2551E-13 -1.9628E-13  2.0199E-15 -4.4281E-15  1.3183E-13 -6.3787E-13
 -1.9628E-13  2.9625E-13 -3.8707E-15  7.2466E-15 -8.8908E-14  1.0323E-12
  2.0199E-15 -3.8707E-15  1.0339E-13 -1.4089E-14 -3.4695E-15 -1.4774E-14
 -4.4281E-15  7.2466E-15 -1.4089E-14  8.1274E-15 -5.5497E-16  2.6276E-14
  1.3183E-13 -8.8908E-14 -3.4695E-15 -5.5497E-16  8.5204E-13 -1.5647E-13
 -6.3787E-13  1.0323E-12 -1.4774E-14  2.6276E-14 -1.5647E-13  3.7278E-12
#      lat0       lon0       xBary       yBary       zBary        JD0
   -2.180644  172.942495   -0.398555   -0.035057   -0.919662  2452370.577573
# Heliocentric elements and errors
Epoch:              2452370.5000  =  2002/04/06
Mean Anomaly:           79.49107 +/-     0.053
Argument of Peri:      198.99423 +/-     0.030
Long of Asc Node:      226.92836 +/-     0.004
Inclination:             2.65233 +/-     0.000
Eccentricity:         0.24500803 +/-    0.0001
Semi-Major Axis:     39.50154405 +/-    0.0066
Time of Perihelion: 2432347.2128 +/-      12.3
Perihelion:          29.82334856 +/-    0.0056
Aphelion:            49.17973953 +/-    0.0086
Period (y)              248.2729 +/-      0.06
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -39.80807106 +/-    0.0014
Ecliptic Y            4.53174579 +/-    0.0002
Ecliptic Z           -1.49048860 +/-    0.0001
Ecliptic XDOT        -0.00095304 +/-    0.0000
Ecliptic YDOT        -0.00252183 +/-    0.0000
Ecliptic ZDOT         0.00004753 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   40.09290209 +/-    0.0014
Geocenter to KBO     39.17134014 +/-    0.0014
# Hcoef:  7.03

The following table shows the complete astrometric record for 02GW31. 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 (02GW31) followed by the observatory code and reference code for the source of the astrometry.

2002 04  06.07683  11 30 37.90   +00 47 52.8   22.0R 02GW31    807  Cf5154      
2002 04  06.16515  11 30 37.54   +00 47 54.9         02GW31    807  Cf5154      
2002 04  07.05224  11 30 33.79   +00 48 21.1         02GW31    807  Cf5154      
2002 04  10.36073  11 30 20.11   +00 49 55.9   22.7R 02GW31    568  Cf5154      
2002 04  10.46099  11 30 19.69   +00 49 58.8         02GW31    568  Cf5154      
2002 05  08.30809  11 28 49.73   +01 00 55.3   22.7R 02GW31    568  Cf7381      
2002 05  08.38457  11 28 49.52   +01 00 56.7         02GW31    568  Cf7381      
2003 03  06.35943  11 38 10.85   +00 01 15.2   22.5R 02GW31    662  Ch8264      
2003 03  06.42532  11 38 10.53   +00 01 17.1         02GW31    662  Ch8264      
2003 04  29.34448  11 34 23.08   +00 27 04.7   23.3R 02GW31    568  Ci0084      
2003 04  30.34889  11 34 20.03   +00 27 27.0         02GW31    568  Ci0084      
2003 05  01.29684  11 34 17.28   +00 27 47.6         02GW31    568  Ci0084      
2003 05  01.38421  11 34 17.00   +00 27 49.5         02GW31    568  Ci0084      
2003 05  05.14749  11 34 06.69   +00 29 08.7         02GW31    290  Ch8264      
2003 05  05.22884  11 34 06.46   +00 29 10.4         02GW31    290  Ch8264      
2004 03  16.23655  11 42 28.23   -00 23 55.7   22.7R 02GW31    695  Ck4262      
2004 03  16.29239  11 42 27.96   -00 23 54.3         02GW31    695  Ck4262      
2013 03  12.29320  12 26 19.47   -04 43 21.6   23.5R 02GW31    G37  C~0qSS      
2013 03  12.42766  12 26 18.85   -04 43 17.6         02GW31    G37  C~0qSS      

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    -0.22       0.00     0.02
  2   0.0002     -5.79     0.28      -0.20    -0.29
  3   0.0027    -67.81    -0.02       1.66     0.01
  4   0.0117   -293.75     0.01       7.76     0.31
  5   0.0120   -300.68    -0.08       7.94     0.35
  6   0.0882  -1799.53     0.33      78.54     0.19
  7   0.0885  -1802.98    -0.11      78.58     0.03
  8   0.9152   7349.71    -0.04     113.14     0.36
  9   0.9154   7344.54    -0.14     112.99     0.25
 10   1.0630   3596.23     0.20     187.10    -0.18
 11   1.0658   3545.38    -0.31     189.52    -0.49
 12   1.0684   3499.33     0.05     192.15    -0.49
 13   1.0686   3494.72    -0.22     192.24    -0.61
 14   1.0789   3321.32     0.09     203.92     0.38
 15   1.0791   3317.48    -0.09     204.12     0.38
 16   1.9443  11502.04     0.11     250.31    -0.00
 17   1.9445  11497.75     0.17     250.00    -0.32
 18  10.9328  55115.55     0.30    1421.97    -0.01
 19  10.9332  55104.74    -0.30    1422.06     0.11

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.

02GW31    quality flag:3

Type:           3:2E      3:2E      3:2E

axisobj        39.239    39.259    39.220
ecceobj         0.246     0.246     0.245
incobj          2.653     2.653     2.653
qmin           29.505    29.518    29.274
qmax           49.991    50.034    50.284
amean          39.456    39.455    39.455
amin           38.998    39.008    38.992
amax           40.000    39.978    39.987
emean           0.228     0.224     0.235
emin            0.206     0.201     0.208
emax            0.253     0.253     0.258
imean           5.369     5.554     4.462
imin            3.679     3.679     2.379
imax            6.651     6.524     6.190
excite_mean     0.247     0.245     0.248
fracstop        1.000     1.000     1.000
cjmean          2.982     2.983     2.981

libcent 0       180.1     180.4     180.7
libamp  0        82.0      78.3      87.4
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       198.7     176.2      96.5
kozaiamp        179.9     179.9     180.0