Orbit Fit and Astrometric record for 18AD39

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: 18AD39    
# Created Fri Dec  3 02:13:59 2021
# Orbit generated from Bernstein formalism
# Fitting     13 observations of     13
# Arc:   2.92y
# First observation: 2018/01/15
#  Last observation: 2020/12/17
Preliminary a, adot, b, bdot, g, gdot:
   0.000103   0.008663  -0.000028  -0.002613   0.013266   0.000000
# Chi-squared of fit:     4.69 DOF:     20 RMS:  0.11
# Min/Max residuals:    -0.27    0.16
# Exact a, adot, b, bdot, g, gdot:
  1.073174E-05  8.901034E-03 -2.746542E-06 -2.678750E-03  1.346061E-02  7.792947E-03
# Covariance matrix:
  6.8968E-13 -8.2693E-13 -7.1136E-14  1.5499E-13 -2.9585E-13 -2.0773E-11
 -8.2693E-13  1.3909E-12  1.4414E-13 -3.1372E-13  6.0579E-13  4.2065E-11
 -7.1136E-14  1.4414E-13  4.1709E-13 -2.7757E-13  9.8738E-14  5.2986E-12
  1.5499E-13 -3.1372E-13 -2.7757E-13  2.8488E-13 -1.8782E-13 -1.1315E-11
 -2.9585E-13  6.0579E-13  9.8738E-14 -1.8782E-13  9.5138E-13  2.6565E-11
 -2.0773E-11  4.2065E-11  5.2986E-12 -1.1315E-11  2.6565E-11  1.5283E-09
#      lat0       lon0       xBary       yBary       zBary        JD0
   11.009762  117.850056    0.050465    0.188697   -0.969138  2458134.123581
# Heliocentric elements and errors
Epoch:              2458130.5000  =  2018/01/12
Mean Anomaly:           14.09446 +/-     0.295
Argument of Peri:       49.02747 +/-     0.043
Long of Asc Node:      330.10733 +/-     0.005
Inclination:            19.76477 +/-     0.002
Eccentricity:         0.76335226 +/-    0.0038
Semi-Major Axis:    163.35236457 +/-    2.2522
Time of Perihelion: 2428274.4496 +/-      90.2
Perihelion:          38.65696716 +/-    0.8126
Aphelion:           288.04776198 +/-    4.0185
Period (y)             2087.8358 +/-     43.18
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -34.48593807 +/-    0.0025
Ecliptic Y           65.36698840 +/-    0.0047
Ecliptic Z           14.18755722 +/-    0.0010
Ecliptic XDOT        -0.00237025 +/-    0.0000
Ecliptic YDOT         0.00061700 +/-    0.0000
Ecliptic ZDOT        -0.00023226 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   75.25563020 +/-    0.0042
Geocenter to KBO     74.29081853 +/-    0.0054
# Hcoef:  6.15

The following table shows the complete astrometric record for 18AD39. 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 (18AD39) followed by the observatory code and reference code for the source of the astrometry.

2018 01  15.62278  08 09 55.503  +31 21 44.29  24.8r 18AD39    568  C~4ZY2      
2018 01  16.61814  08 09 52.194  +31 21 52.70  24.6r 18AD39    568  C~4ZY2      
2018 12  09.32975  08 13 53.576  +30 59 38.38  24.9r 18AD39    304  C~4ZY2      
2018 12  10.32646  08 13 51.271  +30 59 49.56  24.9r 18AD39    304  C~4ZY2      
2018 12  11.30515  08 13 48.999  +31 00 00.67  25.0r 18AD39    304  C~4ZY2      
2019 02  02.17802  08 11 07.417  +31 08 14.09  25.0r 18AD39    304  C~4ZY2      
2019 02  03.18319  08 11 04.165  +31 08 19.45  25.0r 18AD39    304  C~4ZY2      
2019 03  01.08532  08 09 49.077  +31 09 24.22  25.0r 18AD39    304  C~4ZY2      
2019 03  02.07021  08 09 46.642  +31 09 23.54  25.0r 18AD39    304  C~4ZY2      
2019 11  29.30850  08 16 18.448  +30 42 16.31  24.9r 18AD39    304  C~4ZY2      
2019 11  29.34002  08 16 18.381  +30 42 16.53  24.8r 18AD39    304  C~4ZY2      
2019 11  30.32222  08 16 16.661  +30 42 27.24  24.9r 18AD39    304  C~4ZY2      
2020 12  17.29375  08 17 39.619  +30 30 23.11  24.7r 18AD39    304  C~4ZY2      

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    -0.06       0.00    -0.08
     2   0.0027    -43.20     0.05      -1.01     0.02
     3   0.8972   3273.67    -0.05    -614.59     0.16
     4   0.8999   3242.26    -0.15    -610.41     0.03
     5   0.9026   3211.29     0.15    -606.19     0.13
     6   1.0474   1077.23     0.14    -588.64    -0.14
     7   1.0501   1035.32     0.01    -592.60    -0.27
     8   1.1210     80.54     0.06    -740.28     0.12
     9   1.1237     50.18    -0.17    -747.73    -0.02
    10   1.8691   5329.31     0.04   -1201.99     0.12
    11   1.8692   5328.42    -0.06   -1201.98    -0.03
    12   1.8719   5304.34     0.07   -1196.69     0.03
    13   2.9204   6515.68    -0.03   -1651.63    -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.

18AD39    quality flag:3

Type:       SCATNEAR  SCATNEAR  SCATNEAR

axisobj       170.723   178.242   163.911
ecceobj         0.773     0.784     0.762
incobj         19.790    19.788    19.792
qmin           36.831    36.502    37.074
qmax          311.801   325.740   295.253
amean         166.377   172.090   159.481
amin          161.400   166.806   155.068
amax          175.242   182.063   166.989
emean           0.768     0.778     0.757
emin            0.757     0.767     0.747
emax            0.780     0.789     0.769
imean          20.789    20.558    20.542
imin           20.326    20.150    20.215
imax           21.586    21.381    21.174
excite_mean     0.846     0.853     0.835
fracstop        1.000     1.000     1.000
cjmean          2.996     2.989     3.003

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        89.4      88.7      88.3
kozaiamp         43.0      41.6      39.7