Orbit Fit and Astrometric record for 20161

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: 20161     
# Created Sat May 15 01:06:46 2021
# Orbit generated by ELGB
# -->Covariance matrix from a Bernstein fit
# Fitting     33 observations of     33
# Arc:  19.84y
# First observation: 1996/10/08
#  Last observation: 2016/08/12
# Chi-squared of fit:   319.29 DOF:     60 RMS:  0.55
# Min/Max residuals:    -2.09    1.25
# Exact a, adot, b, bdot, g, gdot:
  2.780844E-05  3.189456E-02  2.146539E-06  6.589160E-03  2.894561E-02  1.056672E-02
# Covariance matrix:
  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00
  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00
  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00
  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00
  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00
  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00  0.0000E+00
#      lat0       lon0       xBary       yBary       zBary        JD0
    4.307474    2.095755   -0.236077    0.072478   -0.964260  2450364.837050
# Heliocentric elements and errors
Epoch:              2450364.5000  =  1996/10/08
Mean Anomaly:           31.66805 +/-     0.000
Argument of Peri:      309.87674 +/-     0.000
Long of Asc Node:      343.00186 +/-     0.000
Inclination:            12.39743 +/-     0.000
Eccentricity:         0.40284501 +/-    0.0000
Semi-Major Axis:     48.23521185 +/-    0.0000
Time of Perihelion: 2439600.7529 +/-       0.0
Perihelion:          28.80389768 +/-    0.0000
Aphelion:            67.66652603 +/-    0.0000
Period (y)              335.0075 +/-      0.00
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X           35.39022204 +/-    0.0000
Ecliptic Y            1.52556662 +/-    0.0000
Ecliptic Z            2.59492383 +/-    0.0000
Ecliptic XDOT         0.00084551 +/-    0.0000
Ecliptic YDOT         0.00305419 +/-    0.0000
Ecliptic ZDOT         0.00069637 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   35.51780300 +/-    0.0000
Geocenter to KBO     34.54740032 +/-    0.0000
# Hcoef:  7.42

The following table shows the complete astrometric record for 20161. 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 (20161) followed by the observatory code and reference code for the source of the astrometry.

1996 10  08.33633  00 00 49.41   +04 47 05.9   23.0R 20161     568  C30144      
1996 10  08.38892  00 00 49.20   +04 47 04.5         20161     568  C30144      
1996 10  08.54487  00 00 48.38   +04 47 00.1         20161     568  C30144      
1996 10  12.39995  00 00 29.25   +04 45 02.0         20161     568  C30144      
1996 10  12.44652  00 00 29.01   +04 45 00.4         20161     568  C30144      
1996 10  12.51030  00 00 28.71   +04 44 58.7         20161     568  C30144      
1997 09  05.27890  00 09 45.96   +06 06 53.3         20161     675  Ca0009      
1997 09  05.45828  00 09 45.05   +06 06 48.8         20161     675  Ca0010      
1997 09  06.31941  00 09 40.84   +06 06 27.7   22.5R 20161     675  Ca0010      
1997 09  06.49878  00 09 39.94   +06 06 23.3   22.8R 20161     675  Ca0010      
1998 11  15.31809  00 10 15.40   +06 35 33.5   22.6R 20161     568  Ca3327      
1998 11  15.33171  00 10 15.35   +06 35 33.0   22.6R 20161     568  Ca3327      
1998 11  22.33160  00 09 56.75   +06 33 06.2   22.6R 20161     568  Ca3327      
1998 11  23.27500  00 09 54.61   +06 32 48.4   22.6R 20161     568  Ca3328      
1998 11  24.09341  00 09 52.84   +06 32 33.5   23.1R 20161     711  Ca3585      
1998 11  24.21661  00 09 52.51   +06 32 31.6   23.1R 20161     711  Ca3585      
1998 11  25.09750  00 09 50.63   +06 32 15.3   22.8R 20161     711  Ca3586      
1998 11  25.18707  00 09 50.44   +06 32 13.6   23.1R 20161     711  Ca3586      
2000 11  26.15906  00 21 19.50   +08 30 42.7   22.8R 20161     695  Cc3488      
2000 11  26.27921  00 21 19.22   +08 30 40.6   22.9R 20161     695  Cc3488      
2000 11  27.20699  00 21 17.21   +08 30 22.7   22.5R 20161     695  Cc3488      
2000 11  27.28647  00 21 17.07   +08 30 21.1   22.5R 20161     695  Cc3488      
2008 10  23.35209  01 06 23.49   +15 43 20.7   23.5r 20161     695  C~0gQ7      
2008 10  23.41422  01 06 23.19   +15 43 18.7   24.0r 20161     695  C~0gQ7      
2010 11  01.293101 01 15 49.159  +17 09 44.42  23.1G 20161     F51  C~41LG      
2010 11  01.308754 01 15 49.098  +17 09 44.04  23.0G 20161     F51  C~41LG      
2010 11  01.327123 01 15 48.999  +17 09 43.96  23.1G 20161     F51  C~41LG      
2010 11  01.343380 01 15 48.923  +17 09 43.33  23.7G 20161     F51  C~41LG      
2013 10  05.374621 01 32 40.955  +19 26 55.52  23.3G 20161     F51  C~41LG      
2013 10  05.415522 01 32 40.762  +19 26 54.61  22.9G 20161     F51  C~41LG      
2016 08  12.394873 01 49 42.62   +21 25 28.6         20161     W84  C~3nnZ      
2016 08  12.414259 01 49 42.62   +21 25 28.5         20161     W84  C~3nnZ      
2016 08  12.416105 01 49 42.61   +21 25 28.4         20161     W84  C~3nnZ      

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    -2.09       0.00    -0.58
     2   0.0001      0.00    -1.17       0.00    -0.36
     3   0.0006      0.00    -1.45       0.00     0.07
     4   0.0111      0.00    -0.13       0.00     0.53
     5   0.0113      0.00    -0.22       0.00     0.35
     6   0.0114      0.00     0.06       0.00     0.61
     7   0.9088      0.00     0.68       0.00    -0.68
     8   0.9093      0.00     0.39       0.00    -0.77
     9   0.9117      0.00     0.34       0.00    -0.56
    10   0.9121      0.00     0.29       0.00    -0.48
    11   2.1026      0.00     1.03       0.00    -0.07
    12   2.1027      0.00     0.91       0.00    -0.26
    13   2.1218      0.00     0.48       0.00    -0.09
    14   2.1244      0.00     0.74       0.00     0.08
    15   2.1266      0.00     1.25       0.00     0.45
    16   2.1270      0.00     0.46       0.00     0.81
    17   2.1294      0.00     0.08       0.00     0.43
    18   2.1296      0.00     0.13       0.00     0.33
    19   4.1337      0.00    -0.14       0.00    -0.02
    20   4.1340      0.00    -0.23       0.00     0.24
    21   4.1365      0.00    -0.45       0.00     0.24
    22   4.1368      0.00     0.04       0.00     0.16
    23  12.0411      0.00    -0.52       0.00     0.15
    24  12.0413      0.00    -0.46       0.00    -0.05
    25  14.0642      0.00    -0.34       0.00    -0.53
    26  14.0643      0.00    -0.15       0.00    -0.46
    27  14.0643      0.00    -0.33       0.00    -0.01
    28  14.0644      0.00    -0.31       0.00    -0.18
    29  16.9912      0.00     0.00       0.00     0.02
    30  16.9913      0.00     0.08       0.00    -0.05
    31  19.8441      0.00     0.10       0.00     0.43
    32  19.8442      0.00     0.48       0.00     0.16
    33  19.8442      0.00     0.36       0.00     0.04

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.

20161    quality flag:3

Type:           2:1E      2:1E      2:1E
Type:         6:3EII    6:3EII    6:3EII

axisobj        48.230    48.230    48.229
ecceobj         0.400     0.400     0.400
incobj         12.405    12.405    12.405
qmin           28.171    28.170    28.178
qmax           68.299    68.408    68.361
amean          47.796    47.796    47.796
amin           47.258    47.259    47.272
amax           48.497    48.502    48.522
emean           0.382     0.382     0.382
emin            0.342     0.342     0.342
emax            0.410     0.410     0.410
imean          14.993    14.999    14.991
imin           13.188    13.191    13.200
imax           17.581    17.594    17.571
excite_mean     0.462     0.462     0.462
fracstop        1.000     1.000     1.000
cjmean          2.878     2.878     2.878

libcent 0        66.1      66.6      66.2
libamp  0        15.1      15.4      15.1
libcent 1       123.8     124.4     123.0
libamp  1        99.9     100.0     100.0
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       325.8     325.8     325.8
kozaiamp         31.2      31.2      31.1