Orbit Fit and Astrometric record for 18GT12

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: 18GT12    
# Created Sun Nov 24 02:10:53 2024
# Orbit generated from Bernstein formalism
# Fitting      8 observations of      8
# Arc:   0.81y
# First observation: 2018/04/12
#  Last observation: 2019/02/03
Preliminary a, adot, b, bdot, g, gdot:
  -0.000001   0.016381  -0.000007   0.004442   0.019009   0.000000
# Chi-squared of fit:     3.63 DOF:     10 RMS:  0.12
# Min/Max residuals:    -0.16    0.27
# Exact a, adot, b, bdot, g, gdot:
  1.366139E-05  1.595910E-02  3.080233E-06  4.390516E-03  1.900505E-02 -1.064173E-02
# Covariance matrix:
  7.6035E-13  5.8482E-13 -6.5482E-14  6.1931E-13  2.7031E-12  1.5198E-10
  5.8482E-13  3.1990E-09 -3.7711E-11  5.1948E-10  1.0401E-09  1.3417E-07
 -6.5482E-14 -3.7711E-11  7.4164E-13 -6.6033E-12 -1.2539E-11 -1.5950E-09
  6.1931E-13  5.1948E-10 -6.6033E-12  8.6531E-11  1.7129E-10  2.1906E-08
  2.7031E-12  1.0401E-09 -1.2539E-11  1.7129E-10  3.5036E-10  4.4201E-08
  1.5198E-10  1.3417E-07 -1.5950E-09  2.1906E-08  4.4201E-08  5.6560E-06
#      lat0       lon0       xBary       yBary       zBary        JD0
   -2.834224  163.385520   -0.616628   -0.038741   -0.784798  2458220.547841
# Heliocentric elements and errors
Epoch:              2458220.5000  =  2018/04/12
Mean Anomaly:          341.06243 +/-    10.008
Argument of Peri:       75.77878 +/-     0.913
Long of Asc Node:      174.15162 +/-     0.004
Inclination:            15.54809 +/-     0.006
Eccentricity:         0.65788249 +/-    0.1491
Semi-Major Axis:     98.20919085 +/-   33.9941
Time of Perihelion: 2476920.7931 +/-    1841.1
Perihelion:          33.59908428 +/-   18.6973
Aphelion:           162.81929742 +/-   58.2287
Period (y)              973.2769 +/-    505.33
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -51.28979896 +/-    0.0496
Ecliptic Y           14.65307169 +/-    0.0148
Ecliptic Z           -2.60159410 +/-    0.0025
Ecliptic XDOT         0.00078644 +/-    0.0003
Ecliptic YDOT        -0.00263625 +/-    0.0001
Ecliptic ZDOT         0.00070737 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   53.40528325 +/-    0.0478
Geocenter to KBO     52.61759076 +/-    0.0518
# Hcoef:  7.55

The following table shows the complete astrometric record for 18GT12. 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 (18GT12) followed by the observatory code and reference code for the source of the astrometry.

2018 04  12.04704  10 54 23.994  +03 54 44.67  24.8r 18GT12    807  C~31M1      
2018 04  13.04733  10 54 21.395  +03 55 05.39  24.6r 18GT12    807  C~31M1      
2018 05  14.22340  10 53 27.848  +04 03 27.47        18GT12    G37  C~31M1      
2018 05  14.23067  10 53 27.855  +04 03 27.47        18GT12    G37  C~31M1      
2018 05  15.25994  10 53 27.112  +04 03 38.36        18GT12    G37  C~31M1      
2018 05  15.26719  10 53 27.115  +04 03 38.64        18GT12    G37  C~31M1      
2019 02  02.27366  11 02 03.487  +03 20 20.61  24.7r 18GT12    304  C~31M1      
2019 02  03.26880  11 02 00.514  +03 20 40.39  24.9r 18GT12    304  C~31M1      

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     0.12
     2   0.0027    -43.86     0.08       4.29    -0.11
     3   0.0881   -976.14    -0.15     162.29    -0.16
     4   0.0881   -976.05     0.06     162.33    -0.15
     5   0.0909   -990.48     0.02     168.15     0.03
     6   0.0910   -990.54     0.06     168.43     0.27
     7   0.8110   7147.44    -0.02     728.60    -0.13
     8   0.8137   7098.68     0.02     729.76     0.13

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.

18GT12    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