Orbit Fit and Astrometric record for 20BH157

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: 20BH157   
# Created Tue Apr  1 01:11:18 2025
# Orbit generated from Bernstein formalism
# Fitting      7 observations of      7
# Arc:   1.22y
# First observation: 2020/01/23
#  Last observation: 2021/04/12
Preliminary a, adot, b, bdot, g, gdot:
  -0.000007   0.013599  -0.000002  -0.002829   0.017874   0.000000
# Chi-squared of fit:     5.26 DOF:      8 RMS:  0.15
# Min/Max residuals:    -0.32    0.28
# Exact a, adot, b, bdot, g, gdot:
  1.173605E-05  1.363171E-02 -1.668694E-06 -2.885855E-03  1.793711E-02  4.588196E-03
# Covariance matrix:
  7.3785E-13  5.1296E-13  2.6180E-14 -2.7677E-13  1.5079E-12  7.4329E-11
  5.1296E-13  2.9127E-12  7.8148E-14 -9.6776E-13  3.9129E-12  2.3942E-10
  2.6180E-14  7.8148E-14  4.0792E-13 -5.7136E-13  1.6552E-13  4.2779E-11
 -2.7677E-13 -9.6776E-13 -5.7136E-13  5.3914E-12 -2.3671E-12 -9.1390E-10
  1.5079E-12  3.9129E-12  1.6552E-13 -2.3671E-12  6.9697E-12  5.4644E-10
  7.4329E-11  2.3942E-10  4.2779E-11 -9.1390E-10  5.4644E-10  1.7868E-07
#      lat0       lon0       xBary       yBary       zBary        JD0
   13.346857  128.840726    0.109865    0.227747   -0.959882  2458871.865351
# Heliocentric elements and errors
Epoch:              2458870.5000  =  2020/01/22
Mean Anomaly:           80.67843 +/-     4.327
Argument of Peri:       15.21919 +/-     2.108
Long of Asc Node:      355.91375 +/-     0.010
Inclination:            17.62500 +/-     0.003
Eccentricity:         0.31455394 +/-    0.0235
Semi-Major Axis:     54.18179649 +/-    0.8843
Time of Perihelion: 2426224.2361 +/-    1557.9
Perihelion:          37.13869868 +/-    1.4094
Aphelion:            71.22489429 +/-    1.7234
Period (y)              398.8304 +/-      9.76
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -34.54955990 +/-    0.0050
Ecliptic Y           43.08018761 +/-    0.0062
Ecliptic Z           12.86958978 +/-    0.0019
Ecliptic XDOT        -0.00210346 +/-    0.0000
Ecliptic YDOT        -0.00069276 +/-    0.0000
Ecliptic ZDOT        -0.00026715 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   56.70274240 +/-    0.0056
Geocenter to KBO     55.75034857 +/-    0.0082
# Hcoef:  6.54

The following table shows the complete astrometric record for 20BH157. 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 (20BH157) followed by the observatory code and reference code for the source of the astrometry.

2020 01  23.36455  09 01 16.194  +30 52 50.95  23.8r 20BH157   T09  C~7zrO      
2020 01  23.57248  09 01 15.297  +30 52 54.27  23.7r 20BH157   T09  C~7zrO      
2020 02  25.384448 08 58 58.225  +30 59 23.04  24.1G 20BH157   T12  C~7zrO      
2020 02  25.472665 08 58 57.879  +30 59 23.59  24.1G 20BH157   T12  C~7zrO      
2021 03  18.08840  09 00 58.954  +30 37 29.11  24.0r 20BH157   304  C~7zrO      
2021 03  18.13372  09 00 58.821  +30 37 29.27  24.2r 20BH157   304  C~7zrO      
2021 04  12.03340  09 00 07.628  +30 34 50.45  24.0r 20BH157   304  C~7zrO      

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    -0.18
     2   0.0006    -12.01    -0.02      -0.18    -0.32
     3   0.0904  -1812.87    -0.03    -136.16     0.27
     4   0.0906  -1817.29    -0.01    -136.91     0.28
     5   1.1491     55.01    -0.01    -946.66    -0.11
     6   1.1493     53.32    -0.08    -947.00     0.11
     7   1.2174   -533.47     0.09   -1290.16    -0.04

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.

20BH157    quality flag:3

Type:       SCATNEAR  SCATNEAR  SCATNEAR

axisobj        54.848    57.863    52.684
ecceobj         0.318     0.383     0.256
incobj         17.623    17.623    17.622
qmin           36.244    34.401    38.088
qmax           73.812    81.813    67.472
amean          54.630    57.556    52.463
amin           54.065    56.910    51.977
amax           55.341    58.427    53.099
emean           0.319     0.384     0.257
emin            0.303     0.366     0.242
emax            0.335     0.402     0.272
imean          17.893    17.699    17.935
imin           17.367    16.738    17.523
imax           18.396    18.567    18.317
excite_mean     0.443     0.490     0.401
fracstop        1.000     1.000     1.000
cjmean          2.981     2.956     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       166.7     165.8     163.1
kozaiamp        180.0     180.0     180.0