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: 18AY18 # Created Mon Apr 28 01:11:10 2025 # Orbit generated from Bernstein formalism # Fitting 7 observations of 7 # Arc: 1.05y # First observation: 2018/01/15 # Last observation: 2019/02/03 Preliminary a, adot, b, bdot, g, gdot: 0.000001 0.013583 0.000003 0.002645 0.017393 0.000000 # Chi-squared of fit: 2.71 DOF: 8 RMS: 0.11 # Min/Max residuals: -0.26 0.19 # Exact a, adot, b, bdot, g, gdot: 1.309300E-05 1.366345E-02 2.308464E-06 2.664439E-03 1.733450E-02 5.424048E-03 # Covariance matrix: 7.6229E-13 3.6110E-12 -2.1372E-14 8.7748E-13 4.4474E-12 3.2771E-10 3.6110E-12 6.5582E-10 -3.1328E-12 1.3223E-10 6.8804E-10 4.9404E-08 -2.1372E-14 -3.1328E-12 7.4044E-13 -1.3842E-12 -3.2835E-12 -2.3631E-10 8.7748E-13 1.3223E-10 -1.3842E-12 2.7808E-11 1.3903E-10 9.9789E-09 4.4474E-12 6.8804E-10 -3.2835E-12 1.3903E-10 7.2546E-10 5.1945E-08 3.2771E-10 4.9404E-08 -2.3631E-10 9.9789E-09 5.1945E-08 3.7283E-06 # lat0 lon0 xBary yBary zBary JD0 -9.532442 79.169020 -0.575252 -0.133003 -0.792983 2458133.953931 # Heliocentric elements and errors Epoch: 2458130.5000 = 2018/01/12 Mean Anomaly: 54.63904 +/- 12.018 Argument of Peri: 220.64053 +/- 2.446 Long of Asc Node: 119.43287 +/- 0.012 Inclination: 14.53587 +/- 0.004 Eccentricity: 0.38202291 +/- 0.1290 Semi-Major Axis: 64.49184669 +/- 7.1073 Time of Perihelion: 2429418.9807 +/- 4165.8 Perihelion: 39.85448356 +/- 9.4100 Aphelion: 89.12920982 +/- 12.8739 Period (y) 517.9233 +/- 85.62 # Ecliptic coordinates at JD0 (AU and AU/d) Ecliptic X 10.27432394 +/- 0.0166 Ecliptic Y 56.77018868 +/- 0.0868 Ecliptic Z -9.55346039 +/- 0.0148 Ecliptic XDOT -0.00194178 +/- 0.0001 Ecliptic YDOT 0.00129886 +/- 0.0003 Ecliptic ZDOT 0.00027300 +/- 0.0001 # Distances at JD0 (AU) Heliocenter to KBO 58.47806992 +/- 0.0844 Geocenter to KBO 57.68844051 +/- 0.0896 # Hcoef: 7.40
The following table shows the complete astrometric record for 18AY18. 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 (18AY18) followed by the observatory code and reference code for the source of the astrometry.
2018 01 15.45313 05 16 03.217 +13 29 41.01 25.0r 18AY18 568 C~2yg3 2018 01 16.44877 05 16 00.281 +13 29 45.24 18AY18 568 C~2yg3 2018 12 10.23736 05 21 19.967 +13 41 48.28 25.0r 18AY18 304 C~2yg3 2018 12 11.24155 05 21 16.221 +13 41 45.96 18AY18 304 C~2yg3 2018 12 12.26626 05 21 12.379 +13 41 43.52 18AY18 304 C~2yg3 2019 02 02.10896 05 18 26.515 +13 43 55.56 25.0r 18AY18 304 C~2yg3 2019 02 03.08528 05 18 24.493 +13 44 02.62 25.1r 18AY18 304 C~2yg3
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 -0.13 0.00 0.03
2 0.0027 -42.37 0.13 7.51 -0.03
3 0.9002 4660.13 -0.26 382.78 -0.06
4 0.9029 4605.48 0.09 384.36 0.10
5 0.9057 4549.43 0.19 385.94 0.03
6 1.0477 2147.83 -0.06 694.09 0.02
7 1.0503 2118.97 0.05 703.32 -0.07
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.
18AY18 quality flag:0 Type: ERR2LARGE ERR2LARGE ERR2LARGE axisobj 0.000 0.000 0.000 ecceobj -1.000 -1.000 -1.000 incobj -1.000 -1.000 -1.000 qmin 0.000 0.000 0.000 qmax 0.000 0.000 0.000 amean 0.000 0.000 0.000 amin 0.000 0.000 0.000 amax 0.000 0.000 0.000 emean 0.000 0.000 0.000 emin 0.000 0.000 0.000 emax 0.000 0.000 0.000 imean 0.000 0.000 0.000 imin 0.000 0.000 0.000 imax 0.000 0.000 0.000 excite_mean 0.000 0.000 0.000 fracstop 0.000 0.000 0.000 cjmean 0.000 0.000 0.000 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 0.0 0.0 0.0 kozaiamp 0.0 0.0 0.0