Orbit Fit and Astrometric record for 16GZ251

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: 16GZ251   
# Created Fri Oct 20 01:38:45 2017
# Orbit generated from Bernstein formalism
# Fitting   21 observations of   21
# Arc:   1.09y
# First observation: 2015/03/25
#  Last observation: 2016/04/28
Preliminary a, adot, b, bdot, g, gdot:
  -0.000079   0.140304  -0.000160  -0.071652   0.083255   0.000000
# Chi-squared of fit:    34.60 DOF:   36 RMS:  0.23
# Min/Max residuals:    -0.48    0.51
# Exact a, adot, b, bdot, g, gdot:
  2.636951E-05  1.473133E-01 -1.358115E-05 -7.580922E-02  8.652051E-02  5.725826E-02
# Covariance matrix:
  4.4114E-13  9.9585E-13  6.6423E-14 -8.1207E-13  7.1077E-13  1.0085E-11
  9.9585E-13  3.2476E-11  1.4266E-12 -1.9512E-11  1.0936E-11  2.4420E-10
  6.6423E-14  1.4266E-12  3.5537E-13 -1.1599E-12  5.1187E-13  1.0885E-11
 -8.1207E-13 -1.9512E-11 -1.1599E-12  1.2263E-11 -6.7343E-12 -1.4859E-10
  7.1077E-13  1.0936E-11  5.1187E-13 -6.7343E-12  4.4816E-12  8.4066E-11
  1.0085E-11  2.4420E-10  1.0885E-11 -1.4859E-10  8.4066E-11  1.8594E-09
#      lat0       lon0       xBary       yBary       zBary        JD0
   13.955841 -165.874157    0.169990    0.236345   -0.950540  2457106.934218
# Heliocentric elements and errors
Epoch:              2457100.5000  =  2015/03/19
Mean Anomaly:           27.65336 +/-     0.013
Argument of Peri:       85.68360 +/-     0.013
Long of Asc Node:       37.32411 +/-     0.000
Inclination:            29.32223 +/-     0.000
Eccentricity:         0.43309580 +/-    0.0003
Semi-Major Axis:     17.98259467 +/-    0.0054
Time of Perihelion: 2454960.9506 +/-       0.2
Perihelion:          10.19440836 +/-    0.0059
Aphelion:            25.77078098 +/-    0.0092
Period (y)               76.2582 +/-      0.03
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -11.87207307 +/-    0.0003
Ecliptic Y           -2.81158987 +/-    0.0001
Ecliptic Z            2.78734767 +/-    0.0001
Ecliptic XDOT        -0.00113197 +/-    0.0000
Ecliptic YDOT        -0.00509677 +/-    0.0000
Ecliptic ZDOT        -0.00189103 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   12.51480977 +/-    0.0003
Geocenter to KBO     11.55795278 +/-    0.0003
# Hcoef: 11.18

The following table shows the complete astrometric record for 16GZ251. 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 (16GZ251) followed by the observatory code and reference code for the source of the astrometry.

2015 03  25.43344  13 13 38.148  +07 17 59.02  21.6w 16GZ251   F51  C~1rfC      
2015 03  25.46315  13 13 37.709  +07 18 00.93  21.4w 16GZ251   F51  C~1rfC      
2015 03  25.47817  13 13 37.482  +07 18 01.77  21.7w 16GZ251   F51  C~1rfC      
2015 05  21.27346  13 00 53.555  +07 34 00.34  22.0w 16GZ251   F51  C~1rfC      
2015 05  21.28779  13 00 53.394  +07 33 59.88  21.9w 16GZ251   F51  C~1rfC      
2015 05  21.30211  13 00 53.279  +07 33 59.06  22.2w 16GZ251   F51  C~1rfC      
2016 03  11.51733  13 39 18.84   +00 12 26.3   22.5R 16GZ251   F51  C~1rfC      
2016 03  11.52856  13 39 18.74   +00 12 27.4   23.0R 16GZ251   F51  C~1rfC      
2016 03  11.53981  13 39 18.59   +00 12 27.8   22.1R 16GZ251   F51  C~1rfC      
2016 04  01.41763  13 34 55.070  +00 30 18.44  22.4w 16GZ251   F51  C~1rfC      
2016 04  01.43103  13 34 54.888  +00 30 19.35  21.7w 16GZ251   F51  C~1rfC      
2016 04  01.44448  13 34 54.704  +00 30 20.03  21.8w 16GZ251   F51  C~1rfC      
2016 04  01.45796  13 34 54.498  +00 30 20.44  21.7w 16GZ251   F51  C~1rfC      
2016 04  05.42155  13 33 59.00   +00 33 32.8   21.8R 16GZ251   F51  C~1rfC      
2016 04  05.43644  13 33 58.79   +00 33 33.6   22.0R 16GZ251   F51  C~1rfC      
2016 04  09.49512  13 33 01.08   +00 36 40.7   22.3R 16GZ251   F51  C~1rfC      
2016 04  09.50866  13 33 00.87   +00 36 41.2   22.7R 16GZ251   F51  C~1rfC      
2016 04  09.52188  13 33 00.67   +00 36 42.2   21.8R 16GZ251   F51  C~1rfC      
2016 04  28.35777  13 28 34.40   +00 47 55.9   23.0R 16GZ251   F51  C~1rfC      
2016 04  28.36895  13 28 34.23   +00 47 56.2   23.0R 16GZ251   F51  C~1rfC      
2016 04  28.38015  13 28 34.08   +00 47 56.8   22.8R 16GZ251   F51  C~1rfC      

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     0.11       0.00    -0.06
  2   0.0001     -6.76    -0.01      -0.78     0.07
  3   0.0001    -10.20    -0.10      -1.32    -0.01
  4   0.1556 -10874.77     0.08   -3501.88     0.10
  5   0.1557 -10876.81    -0.26   -3503.22     0.04
  6   0.1557 -10878.08     0.18   -3504.64    -0.10
  7   0.9640  31524.19    -0.31  -14544.29    -0.48
  8   0.9640  31522.33    -0.15  -14543.86     0.18
  9   0.9640  31520.05    -0.41  -14544.38    -0.12
 10   1.0212  27375.81     0.43  -15110.97    -0.16
 11   1.0212  27372.88     0.43  -15111.20     0.12
 12   1.0212  27370.03     0.51  -15111.66     0.17
 13   1.0213  27366.97     0.40  -15112.50    -0.16
 14   1.0321  26510.31     0.12  -15262.29     0.00
 15   1.0322  26507.04     0.14  -15262.79     0.12
 16   1.0433  25622.33    -0.06  -15430.43     0.05
 17   1.0433  25619.19    -0.20  -15431.20    -0.13
 18   1.0434  25615.98    -0.48  -15431.46     0.21
 19   1.0949  21620.40     0.01  -16379.03    -0.01
 20   1.0950  21617.91    -0.20  -16379.76    -0.08
 21   1.0950  21615.57    -0.25  -16380.09     0.25

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.

16GZ251    quality flag:3

Type:       CENTAURR  CENTAURR  CENTAURR

axisobj        17.938    18.029    17.848
ecceobj         0.430     0.432     0.428
incobj         29.298    29.298    29.297
qmin           10.161    10.210    10.106
qmax           25.652    25.816    25.679
amean          17.349    17.947    17.413
amin           16.932    17.739    16.596
amax           18.071    18.246    18.292
emean           0.362     0.393     0.390
emin            0.327     0.370     0.353
emax            0.430     0.433     0.430
imean          30.032    30.251    29.868
imin           28.800    28.800    28.800
imax           31.393    31.098    30.940
excite_mean     0.618     0.639     0.633
fracstop        0.024     0.010     0.021
cjmean          2.961     2.897     2.943

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       174.8     165.6     176.0
kozaiamp        178.4      78.0     178.8