Orbit Fit and Astrometric record for 17DC170

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: 17DC170   
# Created Fri Apr  4 01:11:04 2025
# Orbit generated from Bernstein formalism
# Fitting     23 observations of     24
# Arc:   4.01y
# First observation: 2015/03/30
#  Last observation: 2019/04/03
Preliminary a, adot, b, bdot, g, gdot:
  -0.000096   0.019517  -0.000001  -0.000024   0.021476   0.000000
# Chi-squared of fit:    10.33 DOF:     40 RMS:  0.12
# Min/Max residuals:    -0.24    0.32
# Exact a, adot, b, bdot, g, gdot:
  1.406679E-05  1.940214E-02 -1.675394E-07 -2.373618E-05  2.171187E-02 -1.446062E-03
# Covariance matrix:
  4.3851E-13 -4.5053E-13 -3.3009E-17  8.2718E-16 -3.1243E-14 -4.5572E-12
 -4.5053E-13  6.9432E-13 -8.5342E-17 -1.8685E-15 -5.5317E-14  8.4685E-12
 -3.3009E-17 -8.5342E-17  2.6627E-13 -1.3289E-13  7.8036E-16  4.3418E-16
  8.2718E-16 -1.8685E-15 -1.3289E-13  8.7232E-14  1.6667E-15 -2.2917E-14
 -3.1243E-14 -5.5317E-14  7.8036E-16  1.6667E-15  6.0377E-13  4.8743E-13
 -4.5572E-12  8.4685E-12  4.3418E-16 -2.2917E-14  4.8743E-13  1.2078E-10
#      lat0       lon0       xBary       yBary       zBary        JD0
    3.300029 -172.266708   -0.024869    0.057416   -0.993571  2457111.857159
# Heliocentric elements and errors
Epoch:              2457110.5000  =  2015/03/29
Mean Anomaly:          245.69039 +/-     0.184
Argument of Peri:      213.89524 +/-     0.177
Long of Asc Node:       96.34082 +/-     0.015
Inclination:             3.23106 +/-     0.000
Eccentricity:         0.08180032 +/-    0.0005
Semi-Major Axis:     45.29084106 +/-    0.0067
Time of Perihelion: 2492460.8916 +/-      56.4
Perihelion:          41.58603584 +/-    0.0232
Aphelion:            48.99564628 +/-    0.0235
Period (y)              304.8062 +/-      0.07
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -46.54910692 +/-    0.0016
Ecliptic Y           -6.34618691 +/-    0.0002
Ecliptic Z            2.65130465 +/-    0.0001
Ecliptic XDOT         0.00050612 +/-    0.0000
Ecliptic YDOT        -0.00240572 +/-    0.0000
Ecliptic ZDOT        -0.00001340 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   47.05446695 +/-    0.0016
Geocenter to KBO     46.05776514 +/-    0.0016
# Hcoef:  8.03

The following table shows the complete astrometric record for 17DC170. 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 (17DC170) followed by the observatory code and reference code for the source of the astrometry.

2015 03  30.356381 12 33 36.95   -00 02 08.4         17DC170   T09  C~89UX      
2015 03  30.369488 12 33 36.89   -00 02 08.0         17DC170   T09  C~89UX      
2015 03  30.395233 12 33 36.80   -00 02 07.5         17DC170   T09  C~89UX      
2016 04  04.44255  12 37 19.34   -00 26 06.3   26.1g 17DC170   T09  C~8COu      
2016 04  04.46993  12 37 19.22   -00 26 05.6   25.7g 17DC170   T09  C~8COu      
2016 04  04.47206  12 37 19.22   -00 26 05.5   25.6g 17DC170   T09  C~8COu      
2016 04  04.51521  12 37 19.04   -00 26 04.5   25.6g 17DC170   T09  C~8COu      
2016 04  05.452301 12 37 15.27   -00 25 40.6         17DC170   T09  C~89UX      
2016 04  05.570256 12 37 14.79   -00 25 37.6         17DC170   T09  C~89UX      
2017 02  21.48870  12 44 03.77   -01 10 21.0   24.0z 17DC170   T09  C~89UX      
2017 02  21.51504  12 44 03.73   -01 10 20.5   24.6z 17DC170   T09  C~89UX      
2017 02  21.53656  12 44 03.62   -01 10 20.4   24.3z 17DC170   T09  C~89UX      
2017 02  21.55809  12 44 03.56   -01 10 19.7   24.1z 17DC170   T09  C~89UX      
2017 02  21.56076  12 44 03.53   -01 10 19.7   24.0z 17DC170   T09  C~89UX      
2017 02  21.58766  12 44 03.46   -01 10 18.8   23.5z 17DC170   T09  C~89UX      
2017 02  21.60109  12 44 03.41   -01 10 18.7   24.2z 17DC170   T09  C~89UX      
2017 02  21.60643  12 44 03.41   -01 10 18.7   24.0z 17DC170   T09  C~89UX      
2017 02  23.53005  12 43 57.56   -01 09 35.7   24.6r 17DC170   T09  C~89UX      
2017 02  23.56973  12 43 57.43   -01 09 34.5   25.1r 17DC170   T09  C~89UX      
2017 02  23.60167  12 43 57.32   -01 09 34.1   24.7r 17DC170   T09  C~89UX      
2017 02  23.60376  12 43 57.32   -01 09 34.0   25.1r 17DC170   T09  C~89UX      
2017 02  23.64192  12 43 57.21   -01 09 33.3   25.3r 17DC170   T09  C~89UX      
2017 04  27.380876 12 39 58.33   -00 43 46.4         17DC170   T09  C~89UX      
2019 04  03.469560 12 49 49.08   -01 46 35.9         17DC170   T09  C~89UX      

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     0.01       0.00     0.03
     2   0.0000     -0.98    -0.09       0.01     0.05
     3   0.0001     -2.42     0.20      -0.06    -0.01
     4   1.0160   3632.89    -0.10      -6.73    -0.08
     5   1.0161   3630.96    -0.20      -6.80    -0.12
     6   1.0161   3630.92    -0.09      -6.71    -0.03
     7   1.0162   3628.05    -0.09      -6.85    -0.13
     8   1.0187   3566.64     0.06      -7.17     0.03
     9   1.0191   3558.83     0.11      -7.25     0.06
    10   1.9004  10262.07     0.00     -57.27     0.20
    11   1.9005  10261.32 (   0.60)    -57.05 (   0.37)
    12   1.9006  10259.76     0.13     -57.61    -0.24
    13   1.9006  10258.65     0.13     -57.32     0.01
    14   1.9006  10258.24    -0.15     -57.49    -0.18
    15   1.9007  10256.92    -0.10     -57.08     0.18
    16   1.9007  10256.19    -0.15     -57.28    -0.05
    17   1.9008  10256.19     0.13     -57.28    -0.06
    18   1.9060  10158.37     0.09     -52.29     0.06
    19   1.9061  10156.10    -0.09     -51.95     0.32
    20   1.9062  10154.42    -0.09     -52.24    -0.03
    21   1.9062  10154.38    -0.02     -52.14     0.06
    22   1.9063  10152.59     0.20     -52.15    -0.03
    23   2.0781   6243.93     0.15     -41.38     0.04
    24   4.0113  15901.01    -0.03     -19.49    -0.06

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.

17DC170    quality flag:3

Type:      CLASSICAL CLASSICAL CLASSICAL

axisobj        44.875    44.894    44.855
ecceobj         0.088     0.087     0.088
incobj          3.230     3.230     3.230
qmin           40.557    40.599    40.500
qmax           49.970    49.971    50.017
amean          45.129    45.147    45.109
amin           44.757    44.781    44.741
amax           45.519    45.532    45.508
emean           0.084     0.084     0.084
emin            0.069     0.069     0.069
emax            0.098     0.098     0.099
imean           1.483     1.479     1.500
imin            1.009     1.000     0.997
imax            1.995     1.996     2.023
excite_mean     0.088     0.088     0.089
fracstop        1.000     1.000     1.000
cjmean          3.106     3.106     3.106

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       136.3     138.0     139.4
kozaiamp        180.0     180.0     180.0