Orbit Fit and Astrometric record for 18AY18

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 Tue Apr  1 01:11:09 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