Orbit Fit and Astrometric record for 21DH17

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: 21DH17    
# Created Wed Jul 17 01:11:49 2024
# Orbit generated from Bernstein formalism
# Fitting     15 observations of     15
# Arc:   4.95y
# First observation: 2019/01/28
#  Last observation: 2024/01/09
Preliminary a, adot, b, bdot, g, gdot:
   0.000093   0.015462   0.000015   0.002952   0.019498   0.000000
# Chi-squared of fit:    10.78 DOF:     24 RMS:  0.15
# Min/Max residuals:    -0.33    0.33
# Exact a, adot, b, bdot, g, gdot:
  1.271929E-05  1.552859E-02  1.547586E-06  2.964997E-03  1.952532E-02  5.453238E-04
# Covariance matrix:
  9.9668E-13 -6.2921E-13  1.0032E-13 -9.2215E-14 -2.9922E-13 -5.4949E-12
 -6.2921E-13  8.3161E-13 -1.7381E-13  1.5969E-13  1.0081E-12  9.4625E-12
  1.0032E-13 -1.7381E-13  5.3200E-13 -1.8001E-13 -2.3781E-13 -2.1268E-12
 -9.2215E-14  1.5969E-13 -1.8001E-13  8.5611E-14  2.1844E-13  1.9541E-12
 -2.9922E-13  1.0081E-12 -2.3781E-13  2.1844E-13  1.8397E-12  1.2893E-11
 -5.4949E-12  9.4625E-12 -2.1268E-12  1.9541E-12  1.2893E-11  1.1572E-10
#      lat0       lon0       xBary       yBary       zBary        JD0
    1.359218  150.764778    0.390851    0.021724   -0.910746  2458511.762283
# Heliocentric elements and errors
Epoch:              2458510.5000  =  2019/01/27
Mean Anomaly:          168.83035 +/-     0.237
Argument of Peri:      195.63208 +/-     0.238
Long of Asc Node:      143.39541 +/-     0.001
Inclination:            10.91038 +/-     0.001
Eccentricity:         0.13744171 +/-    0.0002
Semi-Major Axis:     45.90627063 +/-    0.0065
Time of Perihelion: 2405231.6958 +/-      74.0
Perihelion:          39.59683417 +/-    0.0095
Aphelion:            52.21570710 +/-    0.0106
Period (y)              311.0400 +/-      0.07
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -45.28266189 +/-    0.0031
Ecliptic Y           25.78439077 +/-    0.0017
Ecliptic Z            1.21488028 +/-    0.0001
Ecliptic XDOT        -0.00111355 +/-    0.0000
Ecliptic YDOT        -0.00186929 +/-    0.0000
Ecliptic ZDOT         0.00041724 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   52.12322140 +/-    0.0028
Geocenter to KBO     51.21555512 +/-    0.0036
# Hcoef:  6.47

The following table shows the complete astrometric record for 21DH17. 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 (21DH17) followed by the observatory code and reference code for the source of the astrometry.

2019 01  28.261482 10 13 14.85   +12 28 23.2   23.4i 21DH17    W84  C~5zHK      
2020 03  05.135421 10 14 35.36   +12 32 59.5   22.9i 21DH17    W84  C~5zHK      
2021 01  27.228479 10 20 33.24   +12 09 02.1   22.8i 21DH17    W84  C~5zHK      
2021 02  17.29281  10 19 15.665  +12 17 10.92  23.5r 21DH17    568  C~5fvg      
2021 02  17.36006  10 19 15.413  +12 17 12.60  23.3r 21DH17    568  C~5fvg      
2021 02  22.228061 10 18 56.63   +12 19 08.0   23.0i 21DH17    W84  C~5zHK      
2021 04  12.19511  10 16 14.653  +12 35 02.01  24.0r 21DH17    304  C~5fvg      
2021 04  13.13408  10 16 12.554  +12 35 13.88  23.7r 21DH17    304  C~5fvg      
2022 03  07.23886  10 21 45.821  +12 14 19.48  23.8G 21DH17    304  C~5fvg      
2022 03  07.28579  10 21 45.631  +12 14 20.88        21DH17    304  C~5fvg      
2022 04  07.99502  10 20 02.396  +12 24 26.90  24.0r 21DH17    304  C~5fvg      
2022 04  08.99563  10 19 59.866  +12 24 41.17  23.5r 21DH17    304  C~5fvg      
2024 01  09.457450 10 32 17.089  +11 32 49.59  23.8G 21DH17    G37  C~7gyj      
2024 01  09.497470 10 32 16.978  +11 32 50.39        21DH17    G37  C~7gyj      
2024 01  09.535520 10 32 16.886  +11 32 51.28        21DH17    G37  C~7gyj      

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    -0.03       0.00     0.18
     2   1.1003   1003.31     0.09     678.02    -0.33
     3   1.9985   6415.70     0.07    1221.01     0.33
     4   2.0562   5177.64    -0.23    1265.83    -0.09
     5   2.0564   5173.59    -0.11    1266.06     0.03
     6   2.0697   4875.04     0.25    1274.41     0.07
     7   2.2038   2317.33    -0.10    1312.08    -0.01
     8   2.2064   2284.39    -0.04    1312.16    -0.01
     9   3.1047   7293.58     0.18    1902.97    -0.29
    10   3.1048   7290.48    -0.10    1903.26    -0.03
    11   3.1916   5659.17    -0.10    1919.97     0.06
    12   3.1943   5619.42     0.15    1919.87    -0.04
    13   4.9478  16861.56     0.16    2996.08    -0.03
    14   4.9479  16859.74    -0.06    2996.21    -0.02
    15   4.9480  16858.14    -0.14    2996.54     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.

21DH17    quality flag:3

Type:      CLASSICAL CLASSICAL CLASSICAL

axisobj        45.978    45.996    45.960
ecceobj         0.139     0.138     0.139
incobj         10.914    10.914    10.915
qmin           38.890    38.959    38.847
qmax           53.439    53.443    53.427
amean          46.011    46.030    45.988
amin           45.604    45.642    45.594
amax           46.437    46.465    46.411
emean           0.139     0.139     0.139
emin            0.127     0.126     0.127
emax            0.152     0.151     0.152
imean           9.811     9.815     9.815
imin            9.304     9.302     9.293
imax           10.265    10.270    10.282
excite_mean     0.220     0.220     0.220
fracstop        1.000     1.000     1.000
cjmean          3.067     3.067     3.066

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       182.8     182.9     182.4
kozaiamp        180.0     180.0     180.0