Orbit Fit and Astrometric record for 18AX18

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: 18AX18    
# Created Sat Dec  4 02:14:02 2021
# Orbit generated from Bernstein formalism
# Fitting     10 observations of     10
# Arc:   1.87y
# First observation: 2018/01/15
#  Last observation: 2019/11/30
Preliminary a, adot, b, bdot, g, gdot:
  -0.000001   0.011183   0.000003  -0.002311   0.016162   0.000000
# Chi-squared of fit:     7.15 DOF:     14 RMS:  0.15
# Min/Max residuals:    -0.35    0.28
# Exact a, adot, b, bdot, g, gdot:
  1.088220E-05  1.103028E-02 -1.012246E-06 -2.288030E-03  1.620030E-02 -2.583561E-03
# Covariance matrix:
  7.2647E-13 -1.4592E-12 -4.0590E-14  1.6772E-13 -2.9588E-14 -3.2231E-11
 -1.4592E-12  1.1182E-10  1.2893E-12 -1.4256E-11 -8.1950E-11  2.2941E-09
 -4.0590E-14  1.2893E-12  5.0811E-13 -5.4710E-13 -8.4613E-13  2.7789E-11
  1.6772E-13 -1.4256E-11 -5.4710E-13  2.2443E-12  1.0380E-11 -2.9487E-10
 -2.9588E-14 -8.1950E-11 -8.4613E-13  1.0380E-11  6.3289E-11 -1.6513E-09
 -3.2231E-11  2.2941E-09  2.7789E-11 -2.9487E-10 -1.6513E-09  4.7682E-08
#      lat0       lon0       xBary       yBary       zBary        JD0
  -17.344312   78.735255   -0.580816   -0.238355   -0.763719  2458133.918631
# Heliocentric elements and errors
Epoch:              2458130.5000  =  2018/01/12
Mean Anomaly:          239.24559 +/-     2.242
Argument of Peri:       21.25374 +/-     2.042
Long of Asc Node:      204.07258 +/-     0.009
Inclination:            20.56465 +/-     0.002
Eccentricity:         0.29173656 +/-    0.0103
Semi-Major Axis:     52.12232281 +/-    0.1660
Time of Perihelion: 2504234.0720 +/-     827.3
Perihelion:          36.91633558 +/-    0.5479
Aphelion:            67.32831004 +/-    0.5765
Period (y)              376.3083 +/-      1.80
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X           11.09397640 +/-    0.0057
Ecliptic Y           58.67744513 +/-    0.0284
Ecliptic Z          -18.40180534 +/-    0.0090
Ecliptic XDOT        -0.00192618 +/-    0.0000
Ecliptic YDOT        -0.00016257 +/-    0.0000
Ecliptic ZDOT        -0.00023908 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   62.48796140 +/-    0.0268
Geocenter to KBO     61.72724599 +/-    0.0303
# Hcoef:  6.50

The following table shows the complete astrometric record for 18AX18. 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 (18AX18) followed by the observatory code and reference code for the source of the astrometry.

2018 01  15.41783  05 16 48.039  +05 40 25.16  24.4r 18AX18    568  C~2yg3      
2018 01  16.41334  05 16 45.281  +05 40 31.23  24.5r 18AX18    568  C~2yg3      
2018 12  04.14405  05 21 43.188  +05 35 59.28  24.2r 18AX18    304  C~2yg3      
2018 12  04.25870  05 21 42.767  +05 35 58.56        18AX18    304  C~2yg3      
2018 12  04.26384  05 21 42.779  +05 35 58.68  24.3r 18AX18    304  C~2yg3      
2018 12  04.26873  05 21 42.774  +05 35 58.53        18AX18    304  C~2yg3      
2018 12  09.18298  05 21 25.716  +05 35 26.42  24.3r 18AX18    304  C~2yg3      
2018 12  09.21921  05 21 25.582  +05 35 26.51        18AX18    304  C~2yg3      
2019 11  29.28837  05 24 36.193  +05 31 37.33  24.5r 18AX18    304  C~3d0D      
2019 11  30.26850  05 24 32.889  +05 31 28.82  24.3r 18AX18    304  C~3d0D      

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    -0.02       0.00    -0.25
     2   0.0027    -40.57    -0.02       9.27    -0.01
     3   0.8836   4372.92    -0.06    -604.57    -0.04
     4   0.8839   4366.60    -0.35    -604.81     0.09
     5   0.8839   4366.78     0.11    -604.71     0.22
     6   0.8839   4366.70     0.28    -604.85     0.09
     7   0.8974   4110.23     0.08    -617.50    -0.08
     8   0.8975   4108.25     0.02    -617.25     0.22
     9   1.8696   6930.68    -0.04   -1060.79    -0.06
    10   1.8723   6880.79     0.01   -1065.59    -0.18

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.

18AX18    quality flag:2

Type:       SCATNEAR   7:3EEEE  SCATNEAR

axisobj        52.548    53.100    52.205
ecceobj         0.281     0.313     0.254
incobj         20.452    20.447    20.457
qmin           35.783    35.091    37.125
qmax           69.909    71.756    67.558
amean          52.406    52.969    52.001
amin           51.718    52.287    51.497
amax           53.131    53.758    52.607
emean           0.297     0.321     0.268
emin            0.280     0.303     0.252
emax            0.316     0.337     0.284
imean          20.377    20.848    20.491
imin           19.748    20.293    19.946
imax           21.020    21.307    20.992
excite_mean     0.458     0.479     0.441
fracstop        1.000     1.000     1.000
cjmean          2.936     2.916     2.951

libcent 0      -180.0     177.9    -180.0
libamp  0      -180.0     145.7    -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       167.5     155.9     168.8
kozaiamp        179.9     179.9     180.0