Orbit Fit and Astrometric record for 15DA225

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: 15DA225   
# Created Mon Jul 16 01:38:19 2018
# Orbit generated from Bernstein formalism
# Fitting   12 observations of   12
# Arc:   2.84y
# First observation: 2015/02/18
#  Last observation: 2017/12/20
Preliminary a, adot, b, bdot, g, gdot:
   0.000179   0.030617   0.000062  -0.016135   0.028369   0.000000
# Chi-squared of fit:    11.89 DOF:   18 RMS:  0.18
# Min/Max residuals:    -0.38    0.36
# Exact a, adot, b, bdot, g, gdot:
  1.716393E-05  3.028259E-02 -9.028374E-06 -1.585988E-02  2.756009E-02 -6.068956E-03
# Covariance matrix:
  4.5986E-13 -1.8340E-14  3.0631E-14 -2.0718E-13  1.1133E-12  4.5615E-12
 -1.8340E-14  1.5218E-12  1.0277E-13 -7.4714E-13  1.1086E-12  1.6566E-11
  3.0631E-14  1.0277E-13  1.8784E-13 -1.4971E-13  1.8085E-13  1.5692E-12
 -2.0718E-13 -7.4714E-13 -1.4971E-13  6.1797E-13 -1.2556E-12 -1.1194E-11
  1.1133E-12  1.1086E-12  1.8085E-13 -1.2556E-12  4.9370E-12  2.7718E-11
  4.5615E-12  1.6566E-11  1.5692E-12 -1.1194E-11  2.7718E-11  2.4776E-10
#      lat0       lon0       xBary       yBary       zBary        JD0
    0.906560  122.555684   -0.437113    0.014125   -0.883029  2457071.660548
# Heliocentric elements and errors
Epoch:              2457070.5000  =  2015/02/17
Mean Anomaly:          352.21991 +/-     0.019
Argument of Peri:      206.07528 +/-     0.060
Long of Asc Node:      304.92845 +/-     0.000
Inclination:            27.56577 +/-     0.001
Eccentricity:         0.51929569 +/-    0.0006
Semi-Major Axis:     74.23754601 +/-    0.0786
Time of Perihelion: 2462119.6204 +/-       9.7
Perihelion:          35.68630815 +/-    0.0558
Aphelion:           112.78878387 +/-    0.1263
Period (y)              639.6518 +/-      1.02
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X          -20.37007354 +/-    0.0016
Ecliptic Y           31.08854206 +/-    0.0025
Ecliptic Z            0.57374608 +/-    0.0000
Ecliptic XDOT        -0.00222828 +/-    0.0000
Ecliptic YDOT        -0.00211149 +/-    0.0000
Ecliptic ZDOT        -0.00158479 +/-    0.0000
# Distances at JD0 (AU)
Heliocenter to KBO   37.17212030 +/-    0.0022
Geocenter to KBO     36.28435349 +/-    0.0029
# Hcoef:  7.36

The following table shows the complete astrometric record for 15DA225. 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 (15DA225) followed by the observatory code and reference code for the source of the astrometry.

2015 02  18.15977  08 20 12.55   +20 28 18.9   22.5R 15DA225   695  C~1zPy      
2015 02  18.20668  08 20 12.31   +20 28 19.2         15DA225   695  C~1zPy      
2015 02  18.25255  08 20 12.06   +20 28 19.3         15DA225   695  C~1zPy      
2015 03  16.13648  08 18 22.44   +20 29 57.1   22.5R 15DA225   G37  C~1zPy      
2015 03  16.20489  08 18 22.21   +20 29 56.7         15DA225   G37  C~1zPy      
2015 03  23.14108  08 18 02.77   +20 29 48.8   22.7R 15DA225   695  C~1zPy      
2015 03  23.20667  08 18 02.61   +20 29 48.6         15DA225   695  C~1zPy      
2015 03  23.26825  08 18 02.45   +20 29 48.5         15DA225   695  C~1zPy      
2016 03  13.14698  08 24 46.99   +19 12 52.9   22.7R 15DA225   G37  C~1zPy      
2016 03  13.18670  08 24 46.85   +19 12 53.5         15DA225   G37  C~1zPy      
2017 12  20.47860  08 44 22.455  +16 19 35.16  23.4R 15DA225   G37  C~2Uy2      
2017 12  20.51822  08 44 22.281  +16 19 35.54        15DA225   G37  C~2Uy2      

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     0.04       0.00    -0.01
  2   0.0001     -3.35     0.13      -0.48    -0.04
  3   0.0003     -6.80     0.04      -1.18    -0.29
  4   0.0711  -1529.10    -0.35    -255.77     0.18
  5   0.0713  -1532.16    -0.38    -256.89    -0.24
  6   0.0903  -1796.50     0.10    -326.18     0.08
  7   0.0905  -1798.64     0.21    -326.88     0.06
  8   0.0906  -1800.81     0.14    -327.49     0.11
  9   1.0650   4817.13     0.09   -3506.07    -0.12
 10   1.0651   4815.06     0.00   -3505.95     0.36
 11   2.8373  23781.80     0.05   -9453.99    -0.13
 12   2.8374  23779.25    -0.09   -9454.27     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.

15DA225    quality flag:3

Type:       SCATNEAR  SCATNEAR  SCATNEAR

axisobj        73.659    73.847    73.473
ecceobj         0.514     0.515     0.513
incobj         27.612    27.610    27.614
qmin           32.529    33.561    34.091
qmax          117.733   115.046   114.111
amean          73.559    73.492    73.033
amin           72.298    72.191    72.040
amax           75.456    75.123    74.427
emean           0.533     0.521     0.518
emin            0.505     0.503     0.503
emax            0.560     0.541     0.533
imean          27.694    28.628    28.616
imin           26.299    27.467    28.045
imax           29.311    29.690    29.363
excite_mean     0.707     0.708     0.705
fracstop        1.000     1.000     1.000
cjmean          2.750     2.750     2.751

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       189.9     168.6     186.5
kozaiamp        179.9     180.0     180.0