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 Tue Apr 1 01:11:09 2025 # 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 -2.746549E-06 -2.678750E-03 1.346061E-02 7.792950E-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: 14.09443 +/- 0.295 Argument of Peri: 49.02747 +/- 0.043 Long of Asc Node: 330.10733 +/- 0.005 Inclination: 19.76477 +/- 0.002 Eccentricity: 0.76335259 +/- 0.0038 Semi-Major Axis: 163.35255858 +/- 2.2522 Time of Perihelion: 2428274.4573 +/- 90.2 Perihelion: 38.65696068 +/- 0.8126 Aphelion: 288.04815647 +/- 4.0185 Period (y) 2087.8395 +/- 43.18 # Ecliptic coordinates at JD0 (AU and AU/d) Ecliptic X -34.48593794 +/- 0.0025 Ecliptic Y 65.36698815 +/- 0.0047 Ecliptic Z 14.18755717 +/- 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 75.25562992 +/- 0.0042 Geocenter to KBO 74.29081825 +/- 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 170.724 178.242 163.911 ecceobj 0.773 0.784 0.762 incobj 19.790 19.788 19.792 qmin 36.855 36.492 37.046 qmax 311.231 326.932 298.612 amean 166.478 173.307 160.072 amin 161.358 167.561 155.104 amax 174.911 182.587 168.601 emean 0.768 0.779 0.758 emin 0.758 0.769 0.746 emax 0.780 0.791 0.771 imean 20.687 20.516 20.623 imin 20.349 20.185 20.207 imax 21.214 21.216 21.443 excite_mean 0.846 0.855 0.836 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 84.9 84.6 91.1 kozaiamp 38.2 36.5 43.5