Orbit Fit and Astrometric record for 18VG18

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: 18VG18    
# Created Sat Dec  4 02:14:03 2021
# Orbit generated from Bernstein formalism
# Fitting     27 observations of     28
# Arc:   3.00y
# First observation: 2017/01/16
#  Last observation: 2020/01/16
Preliminary a, adot, b, bdot, g, gdot:
   0.000001   0.002907  -0.000002  -0.001297   0.008182   0.000000
# Chi-squared of fit:    23.12 DOF:     48 RMS:  0.16
# Min/Max residuals:    -0.31    0.33
# Exact a, adot, b, bdot, g, gdot:
  5.367217E-06  2.910882E-03 -2.133954E-06 -1.298180E-03  8.157172E-03  5.067968E-04
# Covariance matrix:
  6.9973E-13 -4.4043E-13 -5.9247E-14  9.9027E-14 -4.8046E-13 -2.2389E-11
 -4.4043E-13  4.7127E-13  8.5836E-14 -1.4680E-13  4.7712E-13  3.3115E-11
 -5.9247E-14  8.5836E-14  4.9119E-13 -2.2191E-13  1.1493E-13  7.4119E-12
  9.9027E-14 -1.4680E-13 -2.2191E-13  1.4166E-13 -1.9047E-13 -1.2647E-11
 -4.8046E-13  4.7712E-13  1.1493E-13 -1.9047E-13  1.0392E-12  4.3102E-11
 -2.2389E-11  3.3115E-11  7.4119E-12 -1.2647E-11  4.3102E-11  2.8536E-09
#      lat0       lon0       xBary       yBary       zBary        JD0
   -3.401215   72.532071   -0.674838   -0.042422   -0.717489  2457769.694143
# Heliocentric elements and errors
Epoch:              2457760.5000  =  2017/01/07
Mean Anomaly:          157.59603 +/-     0.832
Argument of Peri:       16.34070 +/-     0.845
Long of Asc Node:      245.35648 +/-     0.002
Inclination:            24.38219 +/-     0.006
Eccentricity:         0.53284303 +/-    0.0012
Semi-Major Axis:     81.36388024 +/-    0.1276
Time of Perihelion: 2340408.9924 +/-     554.2
Perihelion:          38.00970392 +/-    0.1111
Aphelion:           124.71805657 +/-    0.2169
Period (y)              733.9318 +/-      1.73
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X           36.30175888 +/-    0.0045
Ecliptic Y          117.61654044 +/-    0.0146
Ecliptic Z           -7.27337880 +/-    0.0009
Ecliptic XDOT        -0.00088598 +/-    0.0000
Ecliptic YDOT         0.00042387 +/-    0.0000
Ecliptic ZDOT        -0.00044510 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO  123.30600278 +/-    0.0140
Geocenter to KBO    122.59150156 +/-    0.0153
# Hcoef:  3.66

The following table shows the complete astrometric record for 18VG18. 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 (18VG18) followed by the observatory code and reference code for the source of the astrometry.

2017 01  16.193342 04 46 07.80   +18 55 30.7   24.3r 18VG18    W84  C~3syX      
2017 01  16.195407 04 46 07.78   +18 55 30.5         18VG18    W84  C~3syX      
2018 11  10.55241  04 49 36.353  +18 53 10.69  24.6  18VG18    568  C~2rAY      
2018 11  10.59845  04 49 36.262  +18 53 10.36  24.5  18VG18    568  C~2rAY      
2018 12  03.18219  04 48 54.286  +18 51 31.50  24.5  18VG18    304  C~2rAY      
2018 12  03.30293  04 48 54.073  +18 51 30.86        18VG18    304  C~2rAY      
2018 12  04.12222  04 48 52.497  +18 51 27.87        18VG18    304  C~2rAY      
2018 12  08.19843  04 48 44.574  +18 51 11.03        18VG18    304  C~2rAY      
2018 12  08.22737  04 48 44.540  +18 51 11.23        18VG18    304  C~2rAY      
2018 12  09.13542  04 48 42.782  +18 51 07.28  24.6r 18VG18    304  C~2rAY      
2018 12  10.17341  04 48 40.755  +18 51 03.18  24.5r 18VG18    304  C~2rAY      
2018 12  11.20760  04 48 38.762  +18 50 59.23        18VG18    304  C~2rAY      
2018 12  12.21319  04 48 36.828  +18 50 55.30  24.6r 18VG18    304  C~2rAY      
2019 01  06.21324  04 47 51.680  +18 49 32.90  24.3G 18VG18    568  C~3d11      
2019 02  03.07019  04 47 15.664  +18 48 45.20  24.4r 18VG18    304  C~3d11      
2019 03  01.05031  04 47 03.398  +18 48 48.81  24.5r 18VG18    304  C~3d11      
2019 11  26.945423 04 49 50.663  +18 48 45.80        18VG18    950  C~3pOs      
2019 11  26.948008 04 49 50.659  +18 48 45.91  24.3r 18VG18    950  C~3pOs      
2019 11  26.950594 04 49 50.633  +18 48 45.66  24.3r 18VG18    950  C~3pOs      
2019 11  27.068420 04 49 50.398  +18 48 44.79  25.1r 18VG18    950  C~3pOs      
2019 11  27.071005 04 49 50.418  +18 48 45.11  24.6r 18VG18    950  C~3pOs      
2019 11  29.22908  04 49 46.290  +18 48 35.64  24.3r 18VG18    304  C~3d11      
2019 11  30.22140  04 49 44.382  +18 48 31.60  24.3r 18VG18    304  C~3d11      
2020 01  15.825089 04 48 21.222  +18 45 59.34  24.7r 18VG18    950  C~3pOs      
2020 01  15.828265 04 48 21.220  +18 45 58.99  24.7r 18VG18    950  C~3pOs      
2020 01  16.001478 04 48 20.973  +18 45 58.65        18VG18    950  C~3pOs      
2020 01  16.007455 04 48 20.954  +18 45 58.76  25.3r 18VG18    950  C~3pOs      
2020 01  16.012182 04 48 20.959  +18 45 58.82  25.7r 18VG18    950  C~3pOs      

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   0.0000     -0.31    -0.21      -0.16    -0.24
     3   1.8162   2919.64     0.04    -505.32     0.19
     4   1.8163   2918.31    -0.12    -505.49     0.08
     5   1.8781   2314.82    -0.16    -531.01    -0.06
     6   1.8785   2311.74     0.16    -531.28    -0.23
     7   1.8807   2289.17     0.27    -531.51     0.16
     8   1.8919   2175.47    -0.15    -534.44    -0.00
     9   1.8919   2175.02     0.21    -534.19     0.27
    10   1.8944   2149.76     0.12    -535.05    -0.04
    11   1.8973   2120.70    -0.17    -535.59     0.01
    12   1.9001   2092.13    -0.11    -536.04     0.12
    13   1.9029   2064.40    -0.07    -536.57     0.10
    14   1.9713   1418.14     0.10    -539.32     0.12
    15   2.0476    904.79     0.33    -523.13     0.16
    16   2.1187    732.44 (   0.67)   -497.81 (  -0.08)
    17   2.8604   3089.22     0.14    -792.91     0.20
    18   2.8604   3089.18     0.17    -792.79     0.31
    19   2.8604   3088.78    -0.16    -793.00     0.11
    20   2.8607   3085.36    -0.31    -793.46    -0.24
    21   2.8607   3085.68     0.09    -793.17     0.04
    22   2.8666   3026.34     0.07    -795.48    -0.28
    23   2.8693   2998.95     0.07    -796.20    -0.12
    24   2.9969   1808.09    -0.09    -803.05     0.10
    25   2.9969   1808.02    -0.09    -803.40    -0.25
    26   2.9974   1804.49    -0.03    -803.30    -0.25
    27   2.9974   1804.24    -0.17    -803.16    -0.11
    28   2.9975   1804.32     0.01    -803.11    -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.

18VG18    quality flag:2

Type:       SCATNEAR9:2EEEEEEE  SCATNEAR

axisobj        81.998    82.476    81.652
ecceobj         0.524     0.529     0.521
incobj         24.088    24.094    24.083
qmin           36.272    37.574    36.529
qmax          131.071   129.014   129.048
amean          82.113    82.068    81.419
amin           80.686    80.880    80.237
amax           84.104    83.823    83.167
emean           0.538     0.518     0.535
emin            0.517     0.490     0.520
emax            0.560     0.542     0.552
imean          24.960    26.785    24.790
imin           23.856    25.256    24.021
imax           26.271    28.516    25.737
excite_mean     0.684     0.687     0.680
fracstop        1.000     1.000     1.000
cjmean          2.890     2.887     2.892

libcent 0      -180.0     176.1    -180.0
libamp  0      -180.0      86.1    -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       175.9      34.4     139.4
kozaiamp        179.9      14.0     124.3