Orbit Fit and Astrometric record for 17CH55

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: 17CH55    
# Created Thu Oct 31 01:10:32 2024
# Orbit generated from Bernstein formalism
# Fitting     19 observations of     19
# Arc:   4.08y
# First observation: 2015/02/01
#  Last observation: 2019/03/03
Preliminary a, adot, b, bdot, g, gdot:
  -0.000420   0.033990  -0.000043   0.002670   0.029608   0.000000
# Chi-squared of fit:     6.14 DOF:     32 RMS:  0.10
# Min/Max residuals:    -0.18    0.23
# Exact a, adot, b, bdot, g, gdot:
  1.826524E-05  3.356157E-02  1.665150E-06  2.646907E-03  2.911669E-02 -8.488622E-04
# Covariance matrix:
  1.4404E-12 -1.0760E-12  7.1631E-14 -6.9311E-14 -3.6830E-13 -5.4439E-12
 -1.0760E-12  1.1136E-12 -8.9157E-14  8.3653E-14  7.7192E-13  6.4589E-12
  7.1631E-14 -8.9157E-14  5.9371E-13 -2.2426E-13 -7.4585E-14 -5.6366E-13
 -6.9311E-14  8.3653E-14 -2.2426E-13  9.9272E-14  6.5501E-14  5.2903E-13
 -3.6830E-13  7.7192E-13 -7.4585E-14  6.5501E-14  1.1825E-12  4.8605E-12
 -5.4439E-12  6.4589E-12 -5.6366E-13  5.2903E-13  4.8605E-12  4.0854E-11
#      lat0       lon0       xBary       yBary       zBary        JD0
  -11.898688  151.615672    0.332718   -0.190500   -0.904953  2457054.841114
# Heliocentric elements and errors
Epoch:              2457050.5000  =  2015/01/28
Mean Anomaly:          352.44610 +/-     0.040
Argument of Peri:      302.10475 +/-     0.063
Long of Asc Node:      220.09233 +/-     0.002
Inclination:            12.38487 +/-     0.000
Eccentricity:         0.20235188 +/-    0.0001
Semi-Major Axis:     44.04662058 +/-    0.0071
Time of Perihelion: 2459290.9552 +/-      12.0
Perihelion:          35.13370428 +/-    0.0076
Aphelion:            52.95953687 +/-    0.0099
Period (y)              292.3325 +/-      0.07
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -30.22509869 +/-    0.0011
Ecliptic Y           16.70852563 +/-    0.0006
Ecliptic Z           -7.08120469 +/-    0.0003
Ecliptic XDOT        -0.00148042 +/-    0.0000
Ecliptic YDOT        -0.00279460 +/-    0.0000
Ecliptic ZDOT         0.00026009 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   35.25443064 +/-    0.0010
Geocenter to KBO     34.34456126 +/-    0.0013
# Hcoef:  8.22

The following table shows the complete astrometric record for 17CH55. 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 (17CH55) followed by the observatory code and reference code for the source of the astrometry.

2015 02  01.340336 09 57 39.804  -00 14 12.77  23.5r 17CH55    W84  C~8HKI      
2017 02  02.48497  10 12 25.10   -01 17 35.4   24.7r 17CH55    T09  C~7zpj      
2017 02  02.49390  10 12 25.05   -01 17 35.3   24.3r 17CH55    T09  C~7zpj      
2017 02  02.52929  10 12 24.87   -01 17 34.6   24.3r 17CH55    T09  C~7zpj      
2017 02  21.43369  10 10 46.22   -01 08 59.2   23.6z 17CH55    T09  C~7zpj      
2017 02  21.45915  10 10 46.08   -01 08 58.2   23.1z 17CH55    T09  C~7zpj      
2017 02  21.46717  10 10 46.04   -01 08 58.2   22.8z 17CH55    T09  C~7zpj      
2017 03  21.23864  10 08 27.51   -00 52 47.6   22.8y 17CH55    T09  C~7zpj      
2017 03  21.27078  10 08 27.37   -00 52 46.4   22.6y 17CH55    T09  C~7zpj      
2017 03  21.28559  10 08 27.29   -00 52 46.1   22.8y 17CH55    T09  C~7zpj      
2017 03  21.30637  10 08 27.21   -00 52 45.4   23.2y 17CH55    T09  C~7zpj      
2017 03  21.31825  10 08 27.15   -00 52 44.7   23.1y 17CH55    T09  C~7zpj      
2017 03  29.26384  10 07 54.12   -00 47 53.9   25.0g 17CH55    T09  C~7zpj      
2017 03  29.33389  10 07 53.83   -00 47 51.7   24.8g 17CH55    T09  C~7zpj      
2017 03  29.35068  10 07 53.76   -00 47 51.0   25.0g 17CH55    T09  C~7zpj      
2018 02  08.289204 10 19 24.809  -01 47 23.57  22.3z 17CH55    W84  C~8HKI      
2019 02  04.461246 10 27 13.26   -02 20 55.1         17CH55    T09  C~86ur      
2019 02  28.401640 10 25 09.26   -02 09 33.3         17CH55    T09  C~86ur      
2019 03  03.333055 10 24 53.87   -02 07 53.7         17CH55    T09  C~86ur      

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    -0.05
     2   2.0045  13790.17    -0.01    1081.67     0.07
     3   2.0045  13789.43    -0.04    1081.50    -0.05
     4   2.0046  13786.64     0.01    1081.21    -0.13
     5   2.0564  12214.13     0.13    1047.17     0.05
     6   2.0565  12211.80     0.02    1047.38     0.23
     7   2.0565  12211.24     0.16    1047.17     0.01
     8   2.1325   9918.82    -0.04    1230.55     0.10
     9   2.1326   9916.43     0.02    1230.94     0.14
    10   2.1326   9915.20    -0.09    1230.80    -0.16
    11   2.1327   9913.82     0.13    1231.04    -0.14
    12   2.1327   9912.73    -0.06    1231.38     0.07
    13   2.1545   9345.71    -0.00    1330.69     0.20
    14   2.1547   9340.85    -0.04    1331.24    -0.18
    15   2.1547   9339.62    -0.11    1331.52    -0.11
    16   3.0197  20357.49    -0.15    1604.44    -0.06
    17   4.0085  27741.19    -0.09    2168.82    -0.02
    18   4.0741  25728.14     0.03    2161.05     0.02
    19   4.0821  25473.35     0.13    2174.18    -0.02

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.

17CH55    quality flag:2

Type:       SCATEXTD  SCATNEAR  SCATEXTD

axisobj        43.468    45.462    41.703
ecceobj         0.192     0.234     0.155
incobj         12.396    12.347    12.449
qmin           34.453    34.094    34.461
qmax           52.905    57.446    49.268
amean          43.446    45.492    41.726
amin           43.044    45.014    41.359
amax           43.889    46.085    42.125
emean           0.182     0.233     0.149
emin            0.161     0.218     0.128
emax            0.206     0.249     0.171
imean          13.758    13.535    14.242
imin           12.663    12.681    12.812
imax           14.888    14.344    15.632
excite_mean     0.300     0.330     0.288
fracstop        1.000     1.000     1.000
cjmean          2.987     2.986     2.977

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       180.3     176.1     178.6
kozaiamp        180.0     180.0     180.0