Orbit Fit and Astrometric record for 17GY8

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: 17GY8     
# Created Fri Dec  3 02:13:57 2021
# Orbit generated by ELGB
# -->Covariance matrix from a Bernstein fit
# Fitting     77 observations of     77
# Arc:   3.11y
# First observation: 2015/04/08
#  Last observation: 2018/05/19
# Chi-squared of fit:    75.45 DOF:    148 RMS:  0.17
# Min/Max residuals:    -0.44    0.52
# Exact a, adot, b, bdot, g, gdot:
  4.218507E-05  3.349136E-01 -6.244198E-07  1.597197E-03  1.248719E-01 -8.262196E-02
# Covariance matrix:
  4.9067E-13 -1.7943E-11 -3.9571E-14  9.3748E-12  3.0710E-12 -1.5302E-11
 -1.7943E-11  1.9697E-09  5.7633E-12 -1.0448E-09 -2.2217E-10  1.7047E-09
 -3.9571E-14  5.7633E-12  3.1660E-13 -3.2865E-12 -2.7285E-13  5.0385E-12
  9.3748E-12 -1.0448E-09 -3.2865E-12  5.6174E-10  1.1618E-10 -9.0707E-10
  3.0710E-12 -2.2217E-10 -2.7285E-13  1.1618E-10  5.7366E-11 -1.8977E-10
 -1.5302E-11  1.7047E-09  5.0385E-12 -9.0707E-10 -1.8977E-10  1.4799E-09
#      lat0       lon0       xBary       yBary       zBary        JD0
   14.637882  146.494924   -0.778683    0.157964   -0.604149  2457120.562630
# Heliocentric elements and errors
Epoch:              2457120.5000  =  2015/04/08
Mean Anomaly:          357.02112 +/-     0.000
Argument of Peri:      116.52272 +/-     0.000
Long of Asc Node:       56.55651 +/-     0.000
Inclination:            13.58229 +/-     0.000
Eccentricity:         0.68455060 +/-    0.0000
Semi-Major Axis:     26.65823524 +/-    0.0014
Time of Perihelion: 2457536.5031 +/-       3.8
Perihelion:           8.40932426 +/-    0.0004
Aphelion:            44.90714622 +/-    0.0023
Period (y)              137.6434 +/-      0.01
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X           -7.41471702 +/-    0.0000
Ecliptic Y            3.97257930 +/-    0.0000
Ecliptic Z            2.02372485 +/-    0.0000
Ecliptic XDOT        -0.00258784 +/-    0.0000
Ecliptic YDOT        -0.00710123 +/-    0.0000
Ecliptic ZDOT        -0.00042382 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO    8.65192324 +/-    0.0000
Geocenter to KBO      8.00832016 +/-    0.0000
# Hcoef: 13.20

The following table shows the complete astrometric record for 17GY8. 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 (17GY8) followed by the observatory code and reference code for the source of the astrometry.

2015 04  08.061852 10 16 55.04   +26 22 44.3         17GY8     W84  C~3k4x      
2015 04  08.067101 10 16 54.98   +26 22 44.1         17GY8     W84  C~3k4x      
2015 04  12.075469 10 16 22.86   +26 19 20.8         17GY8     W84  C~3k4x      
2015 04  12.076701 10 16 22.86   +26 19 20.8         17GY8     W84  C~3k4x      
2015 12  18.60801  11 51 45.085  +15 11 35.20  22.8G 17GY8     F51  C~2r7d      
2016 01  13.51297  11 54 26.124  +15 30 48.14  22.9G 17GY8     F51  C~2r7d      
2016 02  04.43894  11 52 45.047  +16 06 32.92  21.3G 17GY8     F51  C~2r7d      
2016 03  08.37032  11 44 58.929  +17 08 02.34  23.1G 17GY8     F51  C~2r7d      
2016 03  10.35784  11 44 24.137  +17 11 10.12  22.2G 17GY8     F51  C~2r7d      
2016 03  10.37067  11 44 23.912  +17 11 11.40  22.8G 17GY8     F51  C~2r7d      
2016 03  10.38370  11 44 23.660  +17 11 12.77  21.1G 17GY8     F51  C~2r7d      
2016 03  30.30657  11 38 37.114  +17 34 00.07  22.5G 17GY8     F51  C~2r7d      
2016 03  30.32016  11 38 36.898  +17 34 00.60  22.4G 17GY8     F51  C~2r7d      
2016 03  30.33373  11 38 36.655  +17 34 01.25  22.1G 17GY8     F51  C~2r7d      
2016 03  30.34734  11 38 36.424  +17 34 01.82  22.4G 17GY8     F51  C~2r7d      
2016 04  04.29686  11 37 17.000  +17 36 47.96  22.7G 17GY8     F51  C~2r7d      
2016 04  04.30953  11 37 16.788  +17 36 48.35  22.8G 17GY8     F51  C~2r7d      
2016 04  04.32224  11 37 16.599  +17 36 48.55  22.0G 17GY8     F51  C~2r7d      
2016 04  04.33503  11 37 16.381  +17 36 49.12  22.8G 17GY8     F51  C~2r7d      
2017 03  05.51632  13 00 22.625  +05 52 45.58  23.2w 17GY8     F51  C~2F9C      
2017 03  05.52904  13 00 22.455  +05 52 46.58  23.3w 17GY8     F51  C~2F9C      
2017 03  05.54177  13 00 22.292  +05 52 48.04  22.8w 17GY8     F51  C~2F9C      
2017 03  05.55452  13 00 22.119  +05 52 49.22  22.7w 17GY8     F51  C~2F9C      
2017 03  06.277766 13 00 12.66   +05 53 56.1         17GY8     W84  C~3k4x      
2017 03  06.278987 13 00 12.63   +05 53 56.3         17GY8     W84  C~3k4x      
2017 03  20.34600  12 56 43.110  +06 15 04.99  22.5w 17GY8     F51  C~2F9C      
2017 03  20.35785  12 56 42.913  +06 15 05.76  22.1w 17GY8     F51  C~2F9C      
2017 03  20.38156  12 56 42.514  +06 15 07.42  22.3w 17GY8     F51  C~2F9C      
2017 03  29.39959  12 54 10.862  +06 27 30.16  22.5w 17GY8     F51  C~2F9C      
2017 03  29.41185  12 54 10.648  +06 27 31.35  22.5w 17GY8     F51  C~2F9C      
2017 03  29.42541  12 54 10.415  +06 27 32.02  22.8w 17GY8     F51  C~2F9C      
2017 03  29.43773  12 54 10.186  +06 27 33.18  23.2w 17GY8     F51  C~2F9C      
2017 03  31.233461 12 53 39.22   +06 29 49.7         17GY8     W84  C~3k4x      
2017 03  31.235046 12 53 39.19   +06 29 49.9         17GY8     W84  C~3k4x      
2017 04  03.46951  12 52 43.193  +06 33 40.06  21.9w 17GY8     F51  C~2F9C      
2017 04  03.48341  12 52 42.942  +06 33 40.99  22.2w 17GY8     F51  C~2F9C      
2017 04  03.49732  12 52 42.691  +06 33 41.90  22.0w 17GY8     F51  C~2F9C      
2017 04  03.51127  12 52 42.451  +06 33 42.97  22.0w 17GY8     F51  C~2F9C      
2017 04  04.297409 12 52 28.908  +06 34 36.17  22.0G 17GY8     568  C~2F9C      
2017 04  04.298420 12 52 28.890  +06 34 36.30  21.8G 17GY8     568  C~2F9C      
2017 04  04.299402 12 52 28.880  +06 34 36.31  21.9G 17GY8     568  C~2F9C      
2017 04  16.30888  12 49 04.639  +06 45 39.17  22.1G 17GY8     F51  C~2r7d      
2017 04  16.30952  12 49 04.615  +06 45 39.45  22.1w 17GY8     F51  C~2F9C      
2017 04  16.32092  12 49 04.438  +06 45 39.93  22.3G 17GY8     F51  C~2r7d      
2017 04  16.32156  12 49 04.437  +06 45 39.93  22.6G 17GY8     F51  C~2r7d      
2017 04  16.33298  12 49 04.229  +06 45 40.27  22.3G 17GY8     F51  C~2r7d      
2017 04  16.33362  12 49 04.224  +06 45 40.48  22.2w 17GY8     F51  C~2F9C      
2017 04  16.34506  12 49 04.046  +06 45 40.80  22.2G 17GY8     F51  C~2r7d      
2017 04  16.34570  12 49 04.018  +06 45 41.04  21.9w 17GY8     F51  C~2F9C      
2017 04  20.37350  12 47 58.923  +06 48 10.37  22.7w 17GY8     F51  C~2F9C      
2017 04  20.39487  12 47 58.572  +06 48 11.11  22.6w 17GY8     F51  C~2F9C      
2017 04  20.40559  12 47 58.384  +06 48 11.42  22.6w 17GY8     F51  C~2F9C      
2017 04  21.424071 12 47 42.353  +06 48 42.48  22.2G 17GY8     568  C~2F9C      
2017 04  21.425286 12 47 42.334  +06 48 42.53  22.1G 17GY8     568  C~2F9C      
2017 04  21.426497 12 47 42.313  +06 48 42.50  22.2G 17GY8     568  C~2F9C      
2017 04  21.55476  12 47 40.28   +06 48 47.6         17GY8     Q62  C~2F9C      
2017 04  21.56082  12 47 40.20   +06 48 47.9         17GY8     Q62  C~2F9C      
2017 04  21.56689  12 47 40.10   +06 48 48.0   22.1w 17GY8     Q62  C~2F9C      
2017 04  27.31581  12 46 13.535  +06 50 49.32  22.1G 17GY8     F51  C~2r7d      
2017 04  27.32951  12 46 13.349  +06 50 49.47  22.7G 17GY8     F51  C~2r7d      
2017 04  27.34327  12 46 13.124  +06 50 49.81  22.2G 17GY8     F51  C~2r7d      
2018 03  17.56356  14 03 41.932  -04 33 53.23  23.2G 17GY8     F51  C~2r7d      
2018 03  17.57601  14 03 41.785  -04 33 52.85  22.6G 17GY8     F51  C~2r7d      
2018 03  17.58846  14 03 41.642  -04 33 51.83  23.2G 17GY8     F51  C~2r7d      
2018 03  17.60084  14 03 41.508  -04 33 51.34  23.0G 17GY8     F51  C~2r7d      
2018 03  18.47792  14 03 31.098  -04 33 00.64  22.7G 17GY8     F51  C~2r7d      
2018 03  18.48976  14 03 30.949  -04 32 59.55  23.0G 17GY8     F51  C~2r7d      
2018 03  18.50165  14 03 30.792  -04 32 59.20  22.6G 17GY8     F51  C~2r7d      
2018 03  18.51355  14 03 30.645  -04 32 58.55  22.1G 17GY8     F51  C~2r7d      
2018 04  13.42562  13 57 02.605  -04 06 17.27  22.6G 17GY8     F51  C~2r7d      
2018 04  13.43759  13 57 02.431  -04 06 17.11  23.0G 17GY8     F51  C~2r7d      
2018 04  13.44958  13 57 02.217  -04 06 16.29  23.1G 17GY8     F51  C~2r7d      
2018 04  13.46159  13 57 01.999  -04 06 15.52  22.2G 17GY8     F51  C~2r7d      
2018 05  19.33398  13 47 26.339  -03 43 23.02  21.8G 17GY8     F51  C~2r7d      
2018 05  19.34594  13 47 26.154  -03 43 23.28  22.7G 17GY8     F51  C~2r7d      
2018 05  19.35794  13 47 26.009  -03 43 23.47  22.8G 17GY8     F51  C~2r7d      
2018 05  19.36994  13 47 25.845  -03 43 23.55  22.8G 17GY8     F51  C~2r7d      

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     0.12       0.00     0.14
     2   0.0000      0.00    -0.05       0.00     0.17
     3   0.0110      0.00    -0.25       0.00     0.07
     4   0.0110      0.00    -0.10       0.00     0.14
     5   0.6969      0.00    -0.34       0.00     0.04
     6   0.7678      0.00     0.20       0.00    -0.11
     7   0.8279      0.00     0.05       0.00    -0.19
     8   0.9180      0.00     0.09       0.00    -0.04
     9   0.9235      0.00     0.04       0.00    -0.05
    10   0.9235      0.00     0.12       0.00     0.03
    11   0.9235      0.00    -0.14       0.00     0.18
    12   0.9781      0.00    -0.01       0.00    -0.07
    13   0.9781      0.00     0.19       0.00    -0.11
    14   0.9782      0.00    -0.00       0.00    -0.03
    15   0.9782      0.00    -0.01       0.00    -0.04
    16   0.9917      0.00     0.20       0.00    -0.05
    17   0.9918      0.00     0.06       0.00     0.00
    18   0.9918      0.00     0.28       0.00    -0.14
    19   0.9918      0.00     0.08       0.00     0.10
    20   1.9095      0.00    -0.25       0.00    -0.11
    21   1.9096      0.00    -0.23       0.00    -0.27
    22   1.9096      0.00    -0.10       0.00     0.03
    23   1.9096      0.00    -0.12       0.00     0.05
    24   1.9116      0.00     0.18       0.00     0.03
    25   1.9116      0.00    -0.02       0.00     0.11
    26   1.9501      0.00    -0.13       0.00     0.38
    27   1.9502      0.00    -0.13       0.00     0.12
    28   1.9502      0.00    -0.20       0.00    -0.29
    29   1.9749      0.00    -0.26       0.00    -0.23
    30   1.9749      0.00    -0.23       0.00     0.02
    31   1.9750      0.00    -0.13       0.00    -0.36
    32   1.9750      0.00    -0.30       0.00    -0.14
    33   1.9799      0.00     0.05       0.00    -0.08
    34   1.9799      0.00     0.02       0.00     0.01
    35   1.9888      0.00     0.18       0.00     0.04
    36   1.9888      0.00     0.12       0.00     0.02
    37   1.9889      0.00     0.07       0.00    -0.02
    38   1.9889      0.00     0.18       0.00     0.09
    39   1.9911      0.00     0.01       0.00    -0.11
    40   1.9911      0.00     0.01       0.00    -0.05
    41   1.9911      0.00     0.12       0.00    -0.10
    42   2.0239      0.00    -0.06       0.00    -0.23
    43   2.0239      0.00    -0.26       0.00     0.02
    44   2.0240      0.00    -0.04       0.00     0.02
    45   2.0240      0.00     0.11       0.00    -0.01
    46   2.0240      0.00    -0.12       0.00    -0.15
    47   2.0240      0.00    -0.03       0.00     0.03
    48   2.0240      0.00     0.19       0.00    -0.13
    49   2.0240      0.00    -0.07       0.00     0.08
    50   2.0351      0.00     0.06       0.00     0.19
    51   2.0351      0.00     0.02       0.00     0.24
    52   2.0352      0.00    -0.18       0.00     0.21
    53   2.0380      0.00     0.15       0.00     0.02
    54   2.0380      0.00     0.15       0.00     0.04
    55   2.0380      0.00     0.13       0.00    -0.03
    56   2.0383      0.00    -0.44       0.00     0.36
    57   2.0383      0.00    -0.18       0.00     0.48
    58   2.0383      0.00    -0.22       0.00     0.41
    59   2.0541      0.00    -0.02       0.00    -0.25
    60   2.0541      0.00     0.25       0.00    -0.29
    61   2.0542      0.00    -0.05       0.00    -0.14
    62   2.9418      0.00    -0.15       0.00     0.05
    63   2.9419      0.00    -0.08       0.00    -0.29
    64   2.9419      0.00     0.05       0.00     0.02
    65   2.9419      0.00     0.30       0.00    -0.21
    66   2.9443      0.00     0.01       0.00    -0.05
    67   2.9444      0.00    -0.01       0.00     0.36
    68   2.9444      0.00    -0.15       0.00     0.02
    69   2.9444      0.00    -0.13       0.00    -0.02
    70   3.0154      0.00    -0.28       0.00     0.39
    71   3.0154      0.00     0.22       0.00    -0.17
    72   3.0154      0.00     0.13       0.00    -0.06
    73   3.0155      0.00    -0.01       0.00    -0.01
    74   3.1137      0.00     0.27       0.00     0.52
    75   3.1137      0.00    -0.06       0.00     0.16
    76   3.1137      0.00     0.23       0.00    -0.13
    77   3.1138      0.00     0.22       0.00    -0.31

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.

17GY8    quality flag:3

Type:       CENTAURR  CENTAURR  CENTAURR

axisobj        26.411    26.411    26.412
ecceobj         0.679     0.679     0.679
incobj         13.552    13.552    13.552
qmin            8.177     8.306     8.306
qmax           48.418    44.885    52.417
amean          26.376    25.645    28.077
amin           25.383    23.740    25.675
amax           28.340    26.716    30.508
emean           0.684     0.671     0.697
emin            0.665     0.644     0.677
emax            0.708     0.681     0.718
imean          13.005    13.008    12.671
imin           12.617    12.617    12.556
imax           13.311    13.617    12.874
excite_mean     0.720     0.708     0.730
fracstop        0.001     0.001     0.001
cjmean          2.470     2.505     2.423

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       124.4     120.3     123.2
kozaiamp          8.3       3.8       6.6