Orbit Fit and Astrometric record for 21BK15

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: 21BK15    
# Created Fri May  3 01:18:40 2024
# Orbit generated from Bernstein formalism
# Fitting      9 observations of      9
# Arc:   2.21y
# First observation: 2020/01/24
#  Last observation: 2022/04/09
Preliminary a, adot, b, bdot, g, gdot:
  -0.000002   0.012402  -0.000001   0.001549   0.017138   0.000000
# Chi-squared of fit:     1.68 DOF:     12 RMS:  0.08
# Min/Max residuals:    -0.11    0.14
# Exact a, adot, b, bdot, g, gdot:
  1.101631E-05  1.234582E-02  1.544649E-06  1.541039E-03  1.706459E-02 -4.902465E-03
# Covariance matrix:
  7.1063E-13 -1.5757E-12  5.7372E-14 -2.1331E-13 -1.3495E-12 -7.1638E-11
 -1.5757E-12  8.5272E-12 -3.9049E-13  1.4644E-12  8.4844E-12  5.0020E-10
  5.7372E-14 -3.9049E-13  5.2571E-13 -3.9198E-13 -3.9287E-13 -2.4551E-11
 -2.1331E-13  1.4644E-12 -3.9198E-13  5.6706E-13  1.4651E-12  9.2757E-11
 -1.3495E-12  8.4844E-12 -3.9287E-13  1.4651E-12  8.9962E-12  4.9498E-10
 -7.1638E-11  5.0020E-10 -2.4551E-11  9.2757E-11  4.9498E-10  3.2140E-08
#      lat0       lon0       xBary       yBary       zBary        JD0
    9.337862  143.690045    0.341907    0.151229   -0.919641  2458872.912701
# Heliocentric elements and errors
Epoch:              2458870.5000  =  2020/01/22
Mean Anomaly:          279.69282 +/-     2.071
Argument of Peri:      175.27967 +/-     0.916
Long of Asc Node:       91.57339 +/-     0.013
Inclination:            11.63922 +/-     0.002
Eccentricity:         0.38217644 +/-    0.0097
Semi-Major Axis:     55.22002216 +/-    0.4825
Time of Perihelion: 2492305.0261 +/-     742.6
Perihelion:          34.11623076 +/-    0.6152
Aphelion:            76.32381356 +/-    0.8569
Period (y)              410.3487 +/-      5.38
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -47.14126261 +/-    0.0082
Ecliptic Y           35.06034963 +/-    0.0060
Ecliptic Z            9.50839209 +/-    0.0017
Ecliptic XDOT        -0.00050687 +/-    0.0000
Ecliptic YDOT        -0.00207728 +/-    0.0000
Ecliptic ZDOT         0.00011612 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   59.51416871 +/-    0.0074
Geocenter to KBO     58.60088012 +/-    0.0103
# Hcoef:  7.27

The following table shows the complete astrometric record for 21BK15. 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 (21BK15) followed by the observatory code and reference code for the source of the astrometry.

2020 01  24.41190  09 57 19.353  +22 24 49.14  24.9r 21BK15    568  C~6DKf      
2020 01  24.65187  09 57 18.531  +22 24 54.48  24.8r 21BK15    568  C~6DKf      
2021 01  18.27881  10 00 36.882  +22 13 01.13  24.9r 21BK15    304  C~6DKf      
2021 01  18.33694  10 00 36.680  +22 13 02.32  25.0r 21BK15    304  C~6DKf      
2021 01  19.33255  10 00 33.556  +22 13 24.32  24.9r 21BK15    304  C~6DKf      
2021 03  17.15442  09 57 14.518  +22 30 49.90  25.0r 21BK15    304  C~6DKf      
2021 03  18.15393  09 57 11.380  +22 31 01.18  25.0r 21BK15    304  C~6DKf      
2022 04  08.10028  09 59 16.491  +22 23 48.89  24.9r 21BK15    304  C~6DKf      
2022 04  09.10253  09 59 14.329  +22 23 52.60  24.9r 21BK15    304  C~6DKf      

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     0.09       0.00    -0.02
     2   0.0007    -12.54    -0.10       1.06     0.07
     3   0.9853   2815.86     0.14     294.03     0.05
     4   0.9854   2812.82    -0.05     294.16    -0.11
     5   0.9881   2764.46    -0.08     299.49     0.05
     6   1.1437   -187.93     0.06     315.15    -0.04
     7   1.1465   -232.63    -0.04     310.67    -0.05
     8   2.2031   1543.75     0.02     509.25    -0.08
     9   2.2059   1514.36    -0.04     502.24     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.

21BK15    quality flag:2

Type:         5:2EEE  SCATNEAR  SCATNEAR
Type:         5:2EII                    

axisobj        55.243    56.664    54.022
ecceobj         0.376     0.404     0.349
incobj         11.591    11.587    11.595
qmin           33.755    32.504    34.160
qmax           78.085    84.800    76.869
amean          55.462    56.754    54.866
amin           54.853    54.643    53.707
amax           56.280    59.058    55.854
emean           0.378     0.410     0.360
emin            0.364     0.378     0.342
emax            0.390     0.437     0.377
imean          10.374     8.718     8.992
imin           10.010     7.289     7.886
imax           11.022    10.376    10.133
excite_mean     0.419     0.437     0.392
fracstop        1.000     1.000     1.000
cjmean          3.015     3.006     3.037

libcent 0       179.6    -180.0    -180.0
libamp  0        36.4    -180.0    -180.0
libcent 1       198.5    -180.0    -180.0
libamp  1        66.1    -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       190.2     170.4     187.4
kozaiamp         16.9     180.0     180.0