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: 98WY31
# Created Mon Nov 23 02:36:40 2009
# Orbit generated from Bernstein formalism
# Fitting 18 observations of 18
# Arc: 9.96y
# First observation: 1998/11/18
# Last observation: 2008/11/02
Preliminary a, adot, b, bdot, g, gdot:
0.000181 0.021622 -0.000042 0.000739 0.024302 0.000000
# Chi-squared of fit: 6.11 DOF: 30 RMS: 0.10
# Min/Max residuals: -0.21 0.26
# Exact a, adot, b, bdot, g, gdot:
1.498909E-05 2.088720E-02 7.781104E-07 7.099113E-04 2.254058E-02 -2.344696E-03
# Covariance matrix:
5.6162E-13 -5.4952E-14 -4.8549E-17 4.4832E-16 4.8152E-13 5.3790E-14
-5.4952E-14 2.0101E-13 -8.8218E-15 7.3893E-15 3.1724E-13 9.1677E-13
-4.8549E-17 -8.8218E-15 1.6107E-13 -2.2420E-14 -1.6432E-14 -4.2288E-14
4.4832E-16 7.3893E-15 -2.2420E-14 6.3188E-15 1.4315E-14 3.5636E-14
4.8152E-13 3.1724E-13 -1.6432E-14 1.4315E-14 1.2401E-12 1.7736E-12
5.3790E-14 9.1677E-13 -4.2288E-14 3.5636E-14 1.7736E-12 4.4203E-12
# lat0 lon0 xBary yBary zBary JD0
0.340721 73.748801 0.294934 0.005359 -0.939233 2451135.927691
# Heliocentric elements and errors
Epoch: 2451130.5000 = 1998/11/13
Mean Anomaly: 276.91222 +/- 0.055
Argument of Peri: 105.96358 +/- 0.064
Long of Asc Node: 63.63664 +/- 0.002
Inclination: 1.97375 +/- 0.000
Eccentricity: 0.11468100 +/- 0.0001
Semi-Major Axis: 45.33893373 +/- 0.0084
Time of Perihelion: 2476866.4405 +/- 15.3
Perihelion: 40.13941965 +/- 0.0088
Aphelion: 50.53844782 +/- 0.0105
Period (y) 305.2918 +/- 0.09
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X 12.96886675 +/- 0.0006
Ecliptic Y 43.40971777 +/- 0.0021
Ecliptic Z 0.26386088 +/- 0.0000
Ecliptic XDOT -0.00251609 +/- 0.0000
Ecliptic YDOT 0.00044519 +/- 0.0000
Ecliptic ZDOT 0.00008450 +/- 0.0000
# Distances at JD0 (AU)
Heliocenter to KBO 45.30634309 +/- 0.0020
Geocenter to KBO 44.36442133 +/- 0.0022
# Hcoef: 7.20
The following table shows the complete astrometric record for 98WY31. 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 (98WY31) followed by the observatory code and reference code for the source of the astrometry.
1998 11 18.42696 04 49 19.14 +22 47 19.1 23.1R 98WY31 695 Ca3608 1998 11 18.49839 04 49 18.81 +22 47 18.7 98WY31 695 Ca3608 1999 01 15.19486 04 44 53.45 +22 39 55.9 23.7R 98WY31 695 Ca3608 1999 01 15.29128 04 44 53.08 +22 39 55.3 98WY31 695 Ca3608 2000 12 22.41733 04 56 51.41 +23 04 29.2 23.3R 98WY31 568 Cc3588 2000 12 23.36594 04 56 46.85 +23 04 22.4 98WY31 568 Cc3588 2000 12 23.43951 04 56 46.50 +23 04 21.9 98WY31 568 Cc3588 2000 12 27.28716 04 56 28.329 +23 03 55.28 98WY31 568 Cl2504 2000 12 27.35794 04 56 27.987 +23 03 54.98 98WY31 568 Cl2504 2001 01 25.12123 04 54 36.30 +23 01 05.1 24.0R 98WY31 695 Cc6418 2001 01 25.15704 04 54 36.19 +23 01 05.3 98WY31 695 Cc6418 2001 01 25.19465 04 54 36.07 +23 01 04.8 98WY31 695 Cc6418 2002 01 30.07841 04 59 34.49 +23 10 58.8 21.1 98WY31 304 Cf1458 2002 01 30.10037 04 59 34.44 +23 10 58.7 98WY31 304 Cf1458 2008 11 02.95374 05 43 32.22 +24 07 41.6 26.5R 98WY31 250 S~06AK 2008 11 02.95999 05 43 32.19 +24 07 41.5 98WY31 250 S~06AK 2008 11 02.96694 05 43 32.17 +24 07 41.5 98WY31 250 S~06AK 2008 11 02.97388 05 43 32.13 +24 07 41.4 98WY31 250 S~06AK
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 -0.07 0.00 -0.06 2 0.0002 -4.58 0.09 0.15 0.07 3 0.1582 -3702.88 0.16 17.72 0.04 4 0.1584 -3708.03 -0.21 17.78 0.09 5 2.0944 6326.66 0.10 308.71 0.05 6 2.0970 6263.31 -0.04 308.75 -0.12 7 2.0972 6258.45 0.08 308.78 -0.11 8 2.1078 6006.05 -0.07 309.49 -0.11 9 2.1080 6001.32 -0.15 309.71 0.07 10 2.1867 4449.34 0.11 310.80 -0.11 11 2.1868 4447.85 0.11 311.17 0.26 12 2.1869 4446.15 -0.03 310.86 -0.06 13 3.1996 8607.84 -0.10 458.53 -0.01 14 3.1997 8607.14 0.03 458.51 -0.04 15 9.9590 45707.08 0.13 1511.55 0.11 16 9.9590 45706.65 0.00 1511.46 0.01 17 9.9590 45706.36 0.05 1511.47 0.01 18 9.9591 45705.79 -0.19 1511.38 -0.09
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.
98WY31 quality flag:3 Type: CLASSICAL CLASSICAL CLASSICAL axisobj 45.500 45.526 45.475 ecceobj 0.116 0.116 0.116 incobj 1.974 1.974 1.974 qmin 39.563 39.561 39.543 qmax 51.025 51.109 50.998 amean 45.264 45.293 45.238 amin 45.242 45.263 45.215 amax 45.299 45.339 45.276 emean 0.118 0.118 0.118 emin 0.110 0.110 0.110 emax 0.126 0.127 0.126 imean 1.113 1.114 1.113 imin 0.329 0.336 0.323 imax 1.679 1.681 1.676 excite_mean 0.120 0.120 0.119 fracstop 1.000 1.000 1.000 cjmean 3.100 3.100 3.099 libcent 0 -180.0 -180.0 186.9 libamp 0 -180.0 -180.0 164.9 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 169.0 169.3 168.5 kozaiamp 180.0 180.0 180.0