Orbit Fit and Astrometric record for 17DW165

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: 17DW165   
# Created Tue Apr  1 01:11:04 2025
# Orbit generated from Bernstein formalism
# Fitting     15 observations of     16
# Arc:   3.00y
# First observation: 2016/04/04
#  Last observation: 2019/04/06
Preliminary a, adot, b, bdot, g, gdot:
   0.000025   0.029777   0.000036  -0.004584   0.026525   0.000000
# Chi-squared of fit:     5.01 DOF:     24 RMS:  0.10
# Min/Max residuals:    -0.20    0.24
# Exact a, adot, b, bdot, g, gdot:
  1.744759E-05  2.946613E-02 -3.206863E-06 -4.534563E-03  2.711591E-02 -2.783365E-03
# Covariance matrix:
  7.2600E-13 -8.5722E-13 -5.1670E-14  9.7536E-14 -3.5269E-13 -6.8657E-12
 -8.5722E-13  1.2090E-11  8.8319E-13 -1.8878E-12 -6.9021E-12  1.3357E-10
 -5.1670E-14  8.8319E-13  3.6372E-13 -3.5904E-13 -5.0686E-13  9.9502E-12
  9.7536E-14 -1.8878E-12 -3.5904E-13  5.3947E-13  1.1072E-12 -2.1279E-11
 -3.5269E-13 -6.9021E-12 -5.0686E-13  1.1072E-12  5.3537E-12 -7.8402E-11
 -6.8657E-12  1.3357E-10  9.9502E-12 -2.1279E-11 -7.8402E-11  1.5056E-09
#      lat0       lon0       xBary       yBary       zBary        JD0
    3.822588 -172.581442   -0.128392    0.065989   -0.985664  2457482.957870
# Heliocentric elements and errors
Epoch:              2457480.5000  =  2016/04/02
Mean Anomaly:          338.43796 +/-     0.283
Argument of Peri:      188.95353 +/-     0.448
Long of Asc Node:       30.48984 +/-     0.002
Inclination:             9.50206 +/-     0.001
Eccentricity:         0.19557297 +/-    0.0004
Semi-Major Axis:     45.89724880 +/-    0.0199
Time of Perihelion: 2464282.9547 +/-      89.1
Perihelion:          36.92098758 +/-    0.0234
Aphelion:            54.87351003 +/-    0.0293
Period (y)              310.9483 +/-      0.20
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -37.45538396 +/-    0.0031
Ecliptic Y           -5.00863518 +/-    0.0004
Ecliptic Z            2.45851812 +/-    0.0002
Ecliptic XDOT         0.00063206 +/-    0.0000
Ecliptic YDOT        -0.00292496 +/-    0.0000
Ecliptic ZDOT        -0.00047556 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   37.86867472 +/-    0.0031
Geocenter to KBO     36.87872148 +/-    0.0031
# Hcoef:  8.92

The following table shows the complete astrometric record for 17DW165. 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 (17DW165) followed by the observatory code and reference code for the source of the astrometry.

2016 04  04.457081 12 33 17.12   +00 34 06.3         17DW165   T09  C~83F3      
2016 04  04.523778 12 33 16.79   +00 34 08.0         17DW165   T09  C~83F3      
2017 02  02.664746 12 43 14.41   -00 46 43.8         17DW165   T09  C~83F3      
2017 02  21.49546  12 42 19.21   -00 40 14.1   24.4z 17DW165   T09  C~83F3      
2017 02  21.53656  12 42 19.05   -00 40 13.1   24.1z 17DW165   T09  C~83F3      
2017 02  21.58500  12 42 18.87   -00 40 12.1   23.6z 17DW165   T09  C~83F3      
2017 02  21.60643  12 42 18.79   -00 40 11.4   23.8z 17DW165   T09  C~83F3      
2017 02  23.53005  12 42 11.66   -00 39 23.7   25.1r 17DW165   T09  C~83F3      
2017 02  23.54142  12 42 11.63   -00 39 23.5   24.6r 17DW165   T09  C~83F3      
2017 02  23.56973  12 42 11.53   -00 39 23.0   25.2r 17DW165   T09  C~83F3      
2017 02  23.61219  12 42 11.35   -00 39 21.7   25.2r 17DW165   T09  C~83F3      
2017 02  23.64192  12 42 11.21   -00 39 21.0   25.3r 17DW165   T09  C~83F3      
2017 03  04.54160  12 41 35.23   -00 35 25.8   24.1y 17DW165   T09  C~83F3      
2017 03  04.58243  12 41 35.04   -00 35 24.8   24.4y 17DW165   T09  C~83F3      
2017 03  04.63107  12 41 34.83   -00 35 23.1   24.9y 17DW165   T09  C~83F3      
2019 04  06.501697 12 50 44.81   -02 09 34.9         17DW165   T09  C~83F3      

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    -0.05       0.00     0.12
     2   0.0002     -5.22     0.07      -0.39    -0.02
     3   0.8329  10154.14    -0.00    -923.02    -0.06
     4   0.8844   9237.59     0.01    -891.33     0.05
     5   0.8845   9234.98    -0.08    -891.36     0.01
     6   0.8847   9232.10     0.01    -891.50    -0.16
     7   0.8847   9230.72    -0.06    -891.33     0.01
     8   0.8900   9113.40     0.01    -889.67     0.01
     9   0.8900   9112.90     0.24    -889.66     0.02
    10   0.8901   9111.33 (   0.45)   -889.79 (  -0.12)
    11   0.8902   9108.33     0.14    -889.66    -0.00
    12   0.8903   9106.12    -0.19    -889.85    -0.20
    13   0.9147   8516.35     0.08    -886.54     0.07
    14   0.9148   8513.33    -0.03    -886.74    -0.11
    15   0.9149   8509.76    -0.14    -886.42     0.23
    16   3.0035  18361.15     0.01   -2838.59     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.

17DW165    quality flag:2

Type:      CLASSICAL CLASSICAL  SCATNEAR

axisobj        45.321    45.400    45.243
ecceobj         0.186     0.185     0.186
incobj          9.538     9.538     9.538
qmin           35.908    36.110    36.009
qmax           55.826    55.794    55.546
amean          45.595    45.646    45.487
amin           45.174    45.243    45.039
amax           46.080    46.141    46.009
emean           0.192     0.191     0.185
emin            0.175     0.174     0.167
emax            0.212     0.210     0.208
imean           8.755     8.762     8.600
imin            7.760     7.778     7.712
imax            9.854     9.696     9.579
excite_mean     0.245     0.244     0.238
fracstop        1.000     1.000     1.000
cjmean          3.047     3.048     3.050

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       179.8     181.0     186.2
kozaiamp        179.9     179.9     180.0