Orbit Fit and Astrometric record for 21DG17

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: 21DG17    
# Created Sun Nov 24 02:11:06 2024
# Orbit generated by ELGB
# -->Covariance matrix from a Bernstein fit
# Fitting     17 observations of     17
# Arc:  17.08y
# First observation: 2005/03/12
#  Last observation: 2022/04/08
# Chi-squared of fit:     6.29 DOF:     28 RMS:  0.11
# Min/Max residuals:    -0.20    0.23
# Exact a, adot, b, bdot, g, gdot:
  1.009063E-05  1.007564E-02 -6.415216E-06 -5.819410E-03  1.562635E-02  2.589800E-03
# Covariance matrix:
  4.7627E-13 -5.9750E-14 -2.4131E-14  1.8161E-14 -8.1496E-14 -1.8645E-13
 -5.9750E-14  3.5172E-14  2.6091E-14 -1.9672E-14 -2.2812E-14  2.0200E-13
 -2.4131E-14  2.6091E-14  4.4351E-13 -4.3260E-14 -2.4622E-14  1.6096E-13
  1.8161E-14 -1.9672E-14 -4.3260E-14  1.4107E-14  1.8720E-14 -1.2138E-13
 -8.1496E-14 -2.2812E-14 -2.4622E-14  1.8720E-14  5.0360E-13 -1.9237E-13
 -1.8645E-13  2.0200E-13  1.6096E-13 -1.2138E-13 -1.9237E-13  1.2464E-12
#      lat0       lon0       xBary       yBary       zBary        JD0
    4.957777  142.956738   -0.474502    0.075140   -0.865091  2453441.714857
# Heliocentric elements and errors
Epoch:              2453442.5000  =  2005/03/13
Mean Anomaly:           87.69520 +/-     0.065
Argument of Peri:       57.36373 +/-     0.039
Long of Asc Node:      331.78374 +/-     0.000
Inclination:            30.34971 +/-     0.000
Eccentricity:         0.22510217 +/-    0.0001
Semi-Major Axis:     62.33645601 +/-    0.0123
Time of Perihelion: 2409651.4958 +/-      34.9
Perihelion:          48.30438428 +/-    0.0104
Aphelion:            76.36852773 +/-    0.0156
Period (y)              492.1771 +/-      0.15
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -51.87173900 +/-    0.0023
Ecliptic Y           38.55085082 +/-    0.0017
Ecliptic Z            5.53010619 +/-    0.0003
Ecliptic XDOT        -0.00149452 +/-    0.0000
Ecliptic YDOT        -0.00109079 +/-    0.0000
Ecliptic ZDOT        -0.00097651 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   64.86451491 +/-    0.0021
Geocenter to KBO     63.99435508 +/-    0.0029
# Hcoef:  4.95

The following table shows the complete astrometric record for 21DG17. 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 (21DG17) followed by the observatory code and reference code for the source of the astrometry.

2005 03  12.214114 09 48 01.73   +18 32 36.0   23.3r 21DG17    645  C~5fvg      
2005 03  12.214943 09 48 01.71   +18 32 35.9   22.4i 21DG17    645  C~5fvg      
2005 03  12.217431 09 48 01.72   +18 32 35.8   23.8g 21DG17    645  C~5fvg      
2015 01  26.491654 10 07 43.06   +13 22 33.1   23.2r 21DG17    568  C~5fvg      
2015 01  26.496274 10 07 43.03   +13 22 33.1   23.3r 21DG17    568  C~5fvg      
2015 01  26.505516 10 07 43.00   +13 22 33.2   23.1r 21DG17    568  C~5fvg      
2017 05  19.248257 10 06 47.72   +12 39 34.1         21DG17    568  C~5fvg      
2021 02  17.29607  10 16 10.207  +10 32 34.34  22.9r 21DG17    568  C~5fvg      
2021 02  17.36284  10 16 09.984  +10 32 35.25  22.8r 21DG17    568  C~5fvg      
2021 04  05.99818  10 13 54.275  +10 42 46.18  23.0r 21DG17    304  C~5fvg      
2021 04  07.00063  10 13 52.100  +10 42 55.32  23.2r 21DG17    304  C~5fvg      
2021 04  12.20013  10 13 41.542  +10 43 38.13  23.5r 21DG17    304  C~5fvg      
2022 03  07.23422  10 16 47.816  +10 08 03.40  23.1G 21DG17    304  C~5fvg      
2022 03  07.28016  10 16 47.665  +10 08 04.31  23.4G 21DG17    304  C~5fvg      
2022 04  07.98922  10 15 23.515  +10 14 24.33  23.3r 21DG17    304  C~5fvg      
2022 04  08.16464  10 15 23.144  +10 14 25.79  22.8r 21DG17    304  C~5fvg      
2022 04  08.99013  10 15 21.427  +10 14 33.12  22.8r 21DG17    304  C~5fvg      

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     0.10
     2   0.0000      0.00    -0.20       0.00    -0.01
     3   0.0000      0.00     0.06       0.00    -0.14
     4   9.8762      0.00     0.23       0.00     0.14
     5   9.8762      0.00    -0.01       0.00     0.08
     6   9.8762      0.00    -0.04       0.00     0.05
     7  12.1863      0.00    -0.06       0.00    -0.14
     8  15.9373      0.00    -0.00       0.00     0.00
     9  15.9374      0.00    -0.15       0.00    -0.07
    10  16.0679      0.00     0.20       0.00    -0.08
    11  16.0706      0.00     0.04       0.00     0.04
    12  16.0848      0.00    -0.20       0.00    -0.08
    13  16.9857      0.00     0.06       0.00    -0.16
    14  16.9858      0.00    -0.07       0.00     0.11
    15  17.0726      0.00    -0.03       0.00     0.13
    16  17.0731      0.00     0.08       0.00     0.01
    17  17.0754      0.00     0.08       0.00    -0.01

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.

21DG17    quality flag:3

Type:       SCATNEAR  SCATNEAR  SCATNEAR

axisobj        62.158    62.158    62.157
ecceobj         0.232     0.232     0.232
incobj         30.489    30.489    30.489
qmin           47.053    47.057    46.993
qmax           77.985    77.988    77.984
amean          62.137    62.137    62.137
amin           61.527    61.532    61.526
amax           62.864    62.854    62.867
emean           0.227     0.227     0.227
emin            0.213     0.214     0.213
emax            0.241     0.241     0.240
imean          31.588    31.588    31.588
imin           31.366    31.369    31.364
imax           31.888    31.879    31.899
excite_mean     0.571     0.571     0.571
fracstop        1.000     1.000     1.000
cjmean          2.868     2.868     2.868

libcent 0      -180.0    -180.0     179.7
libamp  0      -180.0    -180.0     170.6
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       183.6     183.6     183.6
kozaiamp        127.3     127.5     127.5