Orbit Fit and Astrometric record for 15SW20

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: 15SW20    
# Created Mon Dec 11 02:38:15 2017
# Orbit generated by ELGB
# -->Covariance matrix from a Bernstein fit
# Fitting   24 observations of   24
# Arc:   0.95y
# First observation: 2015/09/17
#  Last observation: 2016/08/31
# Chi-squared of fit:   269.14 DOF:   42 RMS:  0.59
# Min/Max residuals:    -1.14    1.74
# Exact a, adot, b, bdot, g, gdot:
  9.572192E-06  2.241092E-02  1.735601E-06 -2.017428E-04  2.359413E-02 -8.115803E-03
# Covariance matrix:
  1.6073E-13  2.4274E-11  8.2468E-16 -1.6856E-13  5.6720E-12  9.1931E-10
  2.4274E-11  1.5418E-08  6.1350E-13 -1.0610E-10  3.3900E-09  5.7873E-07
  8.2468E-16  6.1350E-13  8.5325E-14 -9.9104E-14  1.3366E-13  2.3011E-11
 -1.6856E-13 -1.0610E-10 -9.9104E-14  1.1013E-12 -2.3335E-11 -3.9826E-09
  5.6720E-12  3.3900E-09  1.3366E-13 -2.3335E-11  7.4803E-10  1.2729E-07
  9.1931E-10  5.7873E-07  2.3011E-11 -3.9826E-09  1.2729E-07  2.1724E-05
#      lat0       lon0       xBary       yBary       zBary        JD0
   -0.982320   -7.337875   -0.032507   -0.017156   -1.007935  2457283.387669
# Heliocentric elements and errors
Epoch:              2457282.5000  =  2015/09/17
Mean Anomaly:          308.45023 +/-    15.956
Argument of Peri:      334.19803 +/-     0.196
Long of Asc Node:      110.56572 +/-     0.210
Inclination:             1.08521 +/-     0.002
Eccentricity:         0.35816468 +/-    0.2052
Semi-Major Axis:     49.13346818 +/-    7.8671
Time of Perihelion: 2475295.6126 +/-   26480.4
Perihelion:          31.53559534 +/-   11.2773
Aphelion:            66.73134101 +/-   14.6918
Period (y)              344.4089 +/-     82.72
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X           43.03056960 +/-    0.0487
Ecliptic Y           -5.50923571 +/-    0.0063
Ecliptic Z           -0.72651239 +/-    0.0008
Ecliptic XDOT        -0.00060396 +/-    0.0005
Ecliptic YDOT         0.00269312 +/-    0.0001
Ecliptic ZDOT        -0.00000721 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   43.38812440 +/-    0.0483
Geocenter to KBO     42.38367669 +/-    0.0491
# Hcoef:  6.41

The following table shows the complete astrometric record for 15SW20. 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 (15SW20) followed by the observatory code and reference code for the source of the astrometry.

2015 09  17.88688  23 34 36.17   -03 48 52.1   22.5R 15SW20    Z79  C~1cJL      
2015 09  17.95170  23 34 35.89   -03 48 53.8   22.4R 15SW20    Z79  C~1cJL      
2015 09  18.86507  23 34 31.95   -03 49 18.9   22.2R 15SW20    Z79  C~1cJL      
2015 09  18.87314  23 34 31.91   -03 49 19.4   22.2R 15SW20    Z79  C~1cJL      
2015 09  18.87736  23 34 31.91   -03 49 19.6   22.4R 15SW20    Z79  C~1cJL      
2015 09  18.91822  23 34 31.73   -03 49 20.3   22.4R 15SW20    Z79  C~1cJL      
2015 09  18.92225  23 34 31.70   -03 49 20.5   22.5R 15SW20    Z79  C~1cJL      
2015 09  18.92628  23 34 31.70   -03 49 20.4   22.3R 15SW20    Z79  C~1cJL      
2015 09  18.93031  23 34 31.68   -03 49 20.5   22.6R 15SW20    Z79  C~1cJL      
2015 09  18.97650  23 34 31.46   -03 49 21.9   22.4R 15SW20    Z79  C~1cJL      
2015 09  18.98053  23 34 31.45   -03 49 22.1   22.3R 15SW20    Z79  C~1cJL      
2015 09  18.98456  23 34 31.44   -03 49 22.3   22.5R 15SW20    Z79  C~1cJL      
2015 09  18.98863  23 34 31.42   -03 49 22.3   22.6R 15SW20    Z79  C~1cJL      
2015 10  12.93937  23 32 52.46   -03 59 52.1   22.4R 15SW20    J13  C~1cJL      
2015 10  13.06331  23 32 51.98   -03 59 55.4   22.2R 15SW20    J13  C~1cJL      
2015 10  13.06874  23 32 51.93   -03 59 55.1   22.3R 15SW20    J13  C~1cJL      
2015 10  13.07416  23 32 51.93   -03 59 55.4   21.9R 15SW20    J13  C~1cJL      
2015 10  13.07957  23 32 51.91   -03 59 55.2   22.2R 15SW20    J13  C~1cJL      
2016 08  30.07247  23 40 39.59   -03 10 24.3   23.0V 15SW20    J13  C~1xhd      
2016 08  30.07789  23 40 39.56   -03 10 24.8   23.0V 15SW20    J13  C~1xhd      
2016 08  30.08332  23 40 39.52   -03 10 24.6   22.9V 15SW20    J13  C~1xhd      
2016 08  31.06659  23 40 35.50   -03 10 51.5   22.7V 15SW20    J13  C~1xhd      
2016 08  31.07202  23 40 35.47   -03 10 51.7   23.0V 15SW20    J13  C~1xhd      
2016 08  31.07744  23 40 35.45   -03 10 51.9   22.7V 15SW20    J13  C~1xhd      

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    -0.18       0.00    -1.14
  2   0.0002      0.00     1.31       0.00     0.23
  3   0.0027      0.00     1.46       0.00     0.63
  4   0.0027      0.00     1.39       0.00     0.36
  5   0.0027      0.00     1.67       0.00     0.27
  6   0.0028      0.00     1.65       0.00     0.72
  7   0.0028      0.00     1.47       0.00     0.63
  8   0.0028      0.00     1.74       0.00     0.84
  9   0.0029      0.00     1.70       0.00     0.85
 10   0.0030      0.00     1.45       0.00     0.74
 11   0.0030      0.00     1.56       0.00     0.66
 12   0.0030      0.00     1.68       0.00     0.57
 13   0.0030      0.00     1.65       0.00     0.68
 14   0.0686      0.00     1.66       0.00     0.87
 15   0.0689      0.00     1.64       0.00     0.52
 16   0.0689      0.00     1.20       0.00     0.95
 17   0.0690      0.00     1.51       0.00     0.77
 18   0.0690      0.00     1.53       0.00     1.10
 19   0.9505      0.00     0.98       0.00     0.53
 20   0.9506      0.00     0.87       0.00     0.18
 21   0.9506      0.00     0.61       0.00     0.53
 22   0.9533      0.00     1.03       0.00     0.35
 23   0.9533      0.00     0.92       0.00     0.30
 24   0.9533      0.00     0.96       0.00     0.25

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.

15SW20    quality flag:2

Type:       CENTAURR  SCATNEAR  SCATNEAR

axisobj        49.696    49.696    49.697
ecceobj         0.360     0.360     0.360
incobj          1.084     1.084     1.084
qmin           30.181    30.788    31.339
qmax          107.288    81.349    96.682
amean          58.261    45.113    57.441
amin           48.135    37.602    46.672
amax           69.414    56.712    64.570
emean           0.455     0.274     0.434
emin            0.342     0.140     0.314
emax            0.546     0.437     0.497
imean           1.926     3.077     5.030
imin            0.499     0.499     0.499
imax            4.119     5.169     8.168
excite_mean     0.457     0.280     0.444
fracstop        0.624     1.000     1.000
cjmean          2.987     3.013     2.999

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       205.0     174.5     175.2
kozaiamp        179.9     180.0     179.9