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: 18AH39 # Created Mon Apr 28 01:11:10 2025 # Orbit generated from Bernstein formalism # Fitting 9 observations of 9 # Arc: 1.87y # First observation: 2018/01/15 # Last observation: 2019/12/01 Preliminary a, adot, b, bdot, g, gdot: 0.000030 0.010499 0.000009 0.005369 0.016123 0.000000 # Chi-squared of fit: 2.86 DOF: 12 RMS: 0.10 # Min/Max residuals: -0.17 0.25 # Exact a, adot, b, bdot, g, gdot: 9.954778E-06 1.059810E-02 5.350275E-06 5.410420E-03 1.621558E-02 1.541391E-03 # Covariance matrix: 7.1367E-13 -9.3499E-13 5.1455E-14 -2.1612E-13 -4.1049E-13 -2.2428E-11 -9.3499E-13 2.5553E-12 -1.6839E-13 6.5800E-13 2.4600E-13 7.2478E-11 5.1455E-14 -1.6839E-13 5.4265E-13 -4.5180E-13 -8.2299E-14 -6.4342E-12 -2.1612E-13 6.5800E-13 -4.5180E-13 6.7367E-13 4.3238E-13 2.6403E-11 -4.1049E-13 2.4600E-13 -8.2299E-14 4.3238E-13 2.5886E-12 3.7486E-11 -2.2428E-11 7.2478E-11 -6.4342E-12 2.6403E-11 3.7486E-11 2.7929E-09 # lat0 lon0 xBary yBary zBary JD0 11.747476 117.245827 0.040275 0.201256 -0.967089 2458134.110811 # Heliocentric elements and errors Epoch: 2458130.5000 = 2018/01/12 Mean Anomaly: 130.61762 +/- 1.050 Argument of Peri: 239.92952 +/- 0.995 Long of Asc Node: 95.85525 +/- 0.003 Inclination: 29.33049 +/- 0.003 Eccentricity: 0.18123974 +/- 0.0021 Semi-Major Axis: 55.23627530 +/- 0.0526 Time of Perihelion: 2403726.0687 +/- 430.3 Perihelion: 45.22526703 +/- 0.1257 Aphelion: 65.24728358 +/- 0.1334 Period (y) 410.5299 +/- 0.59 # Ecliptic coordinates at JD0 (AU and AU/d) Ecliptic X -28.05998187 +/- 0.0028 Ecliptic Y 54.56866801 +/- 0.0053 Ecliptic Z 12.55604208 +/- 0.0012 Ecliptic XDOT -0.00161640 +/- 0.0000 Ecliptic YDOT -0.00076294 +/- 0.0000 Ecliptic ZDOT 0.00094721 +/- 0.0000 # Distances at JD0 (AU) Heliocenter to KBO 62.63191123 +/- 0.0048 Geocenter to KBO 61.66909983 +/- 0.0061 # Hcoef: 7.12
The following table shows the complete astrometric record for 18AH39. 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 (18AH39) followed by the observatory code and reference code for the source of the astrometry.
2018 01 15.61001 08 07 57.297 +32 12 38.64 24.7r 18AH39 568 C~4ZY2 2018 01 16.60555 08 07 53.322 +32 12 53.31 24.8r 18AH39 568 C~4ZY2 2018 12 09.34013 08 13 15.256 +32 11 44.94 25.1r 18AH39 304 C~4ZY2 2018 12 10.33679 08 13 12.490 +32 12 04.11 25.1r 18AH39 304 C~4ZY2 2018 12 11.29370 08 13 09.805 +32 12 22.37 25.2r 18AH39 304 C~4ZY2 2018 12 11.32868 08 13 09.717 +32 12 22.94 25.1r 18AH39 304 C~4ZY2 2019 02 02.18719 08 09 55.423 +32 26 38.64 25.2r 18AH39 304 C~4ZY2 2019 11 29.31925 08 16 45.254 +32 18 06.85 25.0r 18AH39 304 C~4ZY2 2019 12 01.33258 08 16 40.995 +32 18 45.42 25.0r 18AH39 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 0.08 0.00 -0.02
2 0.0027 -52.42 -0.08 3.47 0.04
3 0.8973 3948.02 0.25 840.61 -0.03
4 0.9000 3909.46 -0.10 851.30 -0.01
5 0.9026 3872.12 -0.17 861.34 -0.06
6 0.9027 3870.90 0.01 861.64 -0.12
7 1.0474 1278.78 0.02 1145.53 0.20
8 1.8692 6453.33 -0.04 1828.73 0.00
9 1.8747 6391.72 0.04 1853.53 -0.01
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.
18AH39 quality flag:2 Type: SCATNEAR SCATNEAR SCATEXTD axisobj 55.533 55.702 55.376 ecceobj 0.183 0.189 0.178 incobj 29.207 29.205 29.208 qmin 43.728 43.939 44.578 qmax 67.958 67.801 66.351 amean 55.491 55.466 55.224 amin 54.840 54.847 54.721 amax 56.143 56.165 55.806 emean 0.184 0.182 0.175 emin 0.152 0.155 0.161 emax 0.211 0.207 0.189 imean 27.714 27.761 27.719 imin 27.264 27.370 27.475 imax 28.259 28.275 27.994 excite_mean 0.500 0.500 0.497 fracstop 1.000 1.000 1.000 cjmean 2.906 2.905 2.907 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 179.2 179.3 203.1 kozaiamp 179.9 180.0 179.9