Orbit Fit and Astrometric record for 21RW237

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: 21RW237   
# Created Tue Apr  1 01:11:26 2025
# Orbit generated from Bernstein formalism
# Fitting      8 observations of      8
# Arc:   2.02y
# First observation: 2019/09/29
#  Last observation: 2021/10/05
Preliminary a, adot, b, bdot, g, gdot:
   0.000005   0.007600  -0.000003  -0.002864   0.013108   0.000000
# Chi-squared of fit:     2.32 DOF:     10 RMS:  0.10
# Min/Max residuals:    -0.21    0.17
# Exact a, adot, b, bdot, g, gdot:
  9.214047E-06  7.675479E-03 -3.688151E-06 -2.892112E-03  1.322402E-02  4.908855E-03
# Covariance matrix:
  7.0231E-13 -1.0409E-12 -4.1673E-14  2.5904E-13 -8.8117E-13 -4.4069E-11
 -1.0409E-12  1.1638E-11  7.1264E-13 -4.4502E-12  2.1917E-11  7.5725E-10
 -4.1673E-14  7.1264E-13  6.6094E-13 -6.2514E-13  1.3955E-12  4.7603E-11
  2.5904E-13 -4.4502E-12 -6.2514E-13  2.0247E-12 -8.7270E-12 -2.9733E-10
 -8.8117E-13  2.1917E-11  1.3955E-12 -8.7270E-12  4.7150E-11  1.4851E-09
 -4.4069E-11  7.5725E-10  4.7603E-11 -2.9733E-10  1.4851E-09  5.0594E-08
#      lat0       lon0       xBary       yBary       zBary        JD0
   -0.469331   -9.294194   -0.259606   -0.007894   -0.965439  2458755.514497
# Heliocentric elements and errors
Epoch:              2458750.5000  =  2019/09/24
Mean Anomaly:           58.06828 +/-     2.529
Argument of Peri:       61.95681 +/-     1.025
Long of Asc Node:      169.66644 +/-     0.000
Inclination:            20.67142 +/-     0.004
Eccentricity:         0.51899801 +/-    0.0177
Semi-Major Axis:     78.15441050 +/-    1.8633
Time of Perihelion: 2418043.8705 +/-    1011.4
Perihelion:          37.59242698 +/-    1.6463
Aphelion:           118.71639402 +/-    3.1493
Period (y)              690.9370 +/-     24.71
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X           75.62259918 +/-    0.0388
Ecliptic Y          -12.11912698 +/-    0.0063
Ecliptic Z           -0.61971922 +/-    0.0003
Ecliptic XDOT         0.00126323 +/-    0.0000
Ecliptic YDOT         0.00140582 +/-    0.0000
Ecliptic ZDOT        -0.00060731 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   76.59004372 +/-    0.0383
Geocenter to KBO     75.61999550 +/-    0.0393
# Hcoef:  6.29

The following table shows the complete astrometric record for 21RW237. 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 (21RW237) followed by the observatory code and reference code for the source of the astrometry.

2019 09  29.013696 23 26 35.049  -04 06 53.41  25.0r 21RW237   W84  C~7XPo      
2019 09  29.177510 23 26 34.643  -04 06 56.31  25.0r 21RW237   W84  C~7XPo      
2020 10  17.010669 23 27 44.658  -04 10 41.87  25.2r 21RW237   W84  C~7XPo      
2020 10  17.174574 23 27 44.308  -04 10 44.30  25.2r 21RW237   W84  C~7XPo      
2021 09  07.105479 23 31 13.342  -03 57 57.03  24.9r 21RW237   W84  C~7XPo      
2021 09  07.194942 23 31 13.098  -03 57 59.02  24.9r 21RW237   W84  C~7XPo      
2021 10  05.001523 23 30 03.865  -04 06 09.48  25.1r 21RW237   W84  C~7XPo      
2021 10  05.173614 23 30 03.452  -04 06 12.32  25.1r 21RW237   W84  C~7XPo      

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    -0.01       0.00     0.05
     2   0.0004     -6.73     0.03      -0.28    -0.01
     3   1.0513    867.33    -0.02    -620.05    -0.03
     4   1.0518    861.56    -0.04    -620.22    -0.03
     5   1.9414   4038.80     0.17   -1148.80     0.04
     6   1.9416   4034.66    -0.20   -1149.18    -0.21
     7   2.0178   2888.91     0.02   -1190.87     0.09
     8   2.0182   2882.11     0.03   -1191.04     0.11

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.

21RW237    quality flag:1

Type:       SCATNEAR  SCATNEAR  SCATNEAR

axisobj        77.725    83.646    73.191
ecceobj         0.513     0.564     0.464
incobj         20.625    20.633    20.616
qmin           36.601    35.210    37.919
qmax          120.868   135.070   110.187
amean          77.663    83.538    73.037
amin           76.606    82.195    72.092
amax           79.228    85.527    74.425
emean           0.514     0.563     0.465
emin            0.500     0.546     0.451
emax            0.528     0.579     0.481
imean          20.313    20.445    20.178
imin           19.705    19.537    19.559
imax           21.165    21.598    20.871
excite_mean     0.620     0.663     0.579
fracstop        1.000     1.000     1.000
cjmean          2.972     2.940     3.001

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       201.0     205.1     187.9
kozaiamp        145.0     180.0     180.0