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: 98WS31
# Created Fri Nov 22 02:07:56 2024
# Orbit generated by ELGB
# -->Covariance matrix from a Bernstein fit
# Fitting 33 observations of 33
# Arc: 22.15y
# First observation: 1998/11/18
# Last observation: 2021/01/11
# Chi-squared of fit: 88.54 DOF: 60 RMS: 0.29
# Min/Max residuals: -1.37 0.68
# Exact a, adot, b, bdot, g, gdot:
1.991388E-05 3.990168E-02 3.315920E-06 4.380969E-03 3.272316E-02 -1.089765E-03
# Covariance matrix:
1.1329E-13 -1.9066E-14 3.8643E-15 -1.6359E-15 5.4189E-14 -1.6330E-14
-1.9066E-14 6.8273E-15 -1.5218E-15 6.9943E-16 -1.0198E-14 6.4534E-15
3.8643E-15 -1.5218E-15 7.5465E-14 -5.0109E-15 4.5256E-15 -1.6867E-15
-1.6359E-15 6.9943E-16 -5.0109E-15 7.3848E-16 -1.2839E-15 7.3776E-16
5.4189E-14 -1.0198E-14 4.5256E-15 -1.2839E-15 1.9104E-13 -1.8864E-14
-1.6330E-14 6.4534E-15 -1.6867E-15 7.3776E-16 -1.8864E-14 7.1373E-15
# lat0 lon0 xBary yBary zBary JD0
2.641138 37.660085 -0.309438 0.042821 -0.933603 2451135.598851
# Heliocentric elements and errors
Epoch: 2451136.5000 = 1998/11/19
Mean Anomaly: 356.54959 +/- 11.303
Argument of Peri: 27.82294 +/- 0.000
Long of Asc Node: 15.90764 +/- 0.000
Inclination: 6.72436 +/- 0.000
Eccentricity: 0.20750526 +/- 0.0002
Semi-Major Axis: 39.71872062 +/- 0.0025
Time of Perihelion: 2452012.8136 +/- 2870.8
Perihelion: 31.47687728 +/- 0.0087
Aphelion: 47.96056395 +/- 0.0090
Period (y) 250.3232 +/- 0.02
# Ecliptic coordinates at JD0 (AU and AU/d)
Ecliptic X 24.72544457 +/- 0.0006
Ecliptic Y 19.46697340 +/- 0.0005
Ecliptic Z 1.40831004 +/- 0.0000
Ecliptic XDOT -0.00212578 +/- 0.0000
Ecliptic YDOT 0.00258602 +/- 0.0000
Ecliptic ZDOT 0.00036192 +/- 0.0000
# Distances at JD0 (AU)
Heliocenter to KBO 31.50070794 +/- 0.0006
Geocenter to KBO 30.55944517 +/- 0.0008
# Hcoef: 8.24
The following table shows the complete astrometric record for 98WS31. 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 (98WS31) followed by the observatory code and reference code for the source of the astrometry.
1998 11 18.09812 02 17 37.85 +16 33 43.0 22.5R 98WS31 695 a3608 1998 11 18.16698 02 17 37.44 +16 33 41.4 98WS31 695 a3608 1998 11 18.24713 02 17 36.96 +16 33 39.1 98WS31 695 a3608 1998 12 17.84201 02 15 13.98 +16 21 24.9 23.1R 98WS31 950 a3608 1998 12 17.87639 02 15 13.85 +16 21 24.2 98WS31 950 a3608 1998 12 17.91186 02 15 13.72 +16 21 23.7 98WS31 950 a3608 1999 11 30.19125 02 25 14.98 +17 27 05.5 22.8R 98WS31 695 Ca8499 1999 11 30.19836 02 25 14.98 +17 27 05.1 22.7R 98WS31 695 Ca8499 1999 11 30.30921 02 25 14.37 +17 27 02.3 22.4R 98WS31 695 Ca8499 1999 11 30.31631 02 25 14.34 +17 27 02.0 22.6R 98WS31 695 Ca8499 2000 01 02.15602 02 23 07.83 +17 15 47.1 23.3R 98WS31 697 Ca8499 2000 01 02.20304 02 23 07.62 +17 15 46.0 23.2R 98WS31 697 Ca8499 2000 01 02.22104 02 23 07.72 +17 15 46.0 98WS31 568 Ca8499 2000 01 02.23592 02 23 07.69 +17 15 45.7 23.2R 98WS31 568 Ca8499 2000 01 02.24998 02 23 07.65 +17 15 45.5 98WS31 568 Ca8499 2000 01 03.23913 02 23 05.61 +17 15 33.3 23.1R 98WS31 697 Ca8499 2000 01 05.11914 02 23 02.19 +17 15 10.8 23.2R 98WS31 697 Ca8499 2000 01 05.18084 02 23 02.09 +17 15 10.0 23.1R 98WS31 697 Ca8499 2002 09 11.39596 02 59 14.29 +20 39 18.5 22.2R 98WS31 662 Cg2658 2002 09 11.49551 02 59 14.06 +20 39 17.8 98WS31 662 Cg2658 2008 10 22.31914 03 52 05.54 +25 09 17.3 24.6r 98WS31 695 C~0gLs 2008 10 22.40810 03 52 05.01 +25 09 16.7 23.6r 98WS31 695 C~0gLs 2008 11 21.65583 03 48 50.40 +25 01 56.8 24.1R 98WS31 250 S~06AK 2008 11 21.66208 03 48 50.35 +25 01 56.7 98WS31 250 S~06AK 2008 11 21.66902 03 48 50.31 +25 01 56.5 98WS31 250 S~06AK 2008 11 21.67527 03 48 50.26 +25 01 56.5 98WS31 250 S~06AK 2008 12 22.24248 03 45 35.00 +24 51 38.6 22.1r 98WS31 695 C~0hkJ 2008 12 22.33359 03 45 34.50 +24 51 36.6 22.0r 98WS31 695 C~0hkJ 2016 02 04.17536 04 50 06.37 +28 27 28.5 23.3R 98WS31 G37 C~1lut 2016 02 04.30652 04 50 06.04 +28 27 26.3 98WS31 G37 C~1lut 2021 01 11.293190 05 40 23.959 +29 54 07.97 23.3G 98WS31 G37 C~4Tva 2021 01 11.338770 05 40 23.674 +29 54 07.59 98WS31 G37 C~4Tva 2021 01 11.383750 05 40 23.400 +29 54 07.12 98WS31 G37 C~4Tva
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 -0.28
2 0.0002 0.00 -0.07 0.00 0.06
3 0.0004 0.00 -0.12 0.00 0.03
4 0.0814 0.00 -0.04 0.00 0.07
5 0.0815 0.00 -0.11 0.00 0.03
6 0.0816 0.00 -0.12 0.00 0.22
7 1.0324 0.00 -0.46 0.00 0.19
8 1.0324 0.00 0.12 0.00 -0.02
9 1.0327 0.00 0.02 0.00 0.10
10 1.0328 0.00 0.15 0.00 -0.01
11 1.1227 0.00 0.24 0.00 0.03
12 1.1228 0.00 -1.37 0.00 -0.45
13 1.1229 0.00 0.52 0.00 -0.28
14 1.1229 0.00 0.56 0.00 -0.39
15 1.1229 0.00 0.42 0.00 -0.40
16 1.1256 0.00 -0.14 0.00 0.10
17 1.1308 0.00 0.16 0.00 0.09
18 1.1310 0.00 0.35 0.00 -0.00
19 3.8146 0.00 -0.26 0.00 0.68
20 3.8149 0.00 0.40 0.00 0.21
21 9.9281 0.00 0.14 0.00 0.11
22 9.9283 0.00 -0.14 0.00 0.35
23 10.0111 0.00 -0.13 0.00 -0.13
24 10.0111 0.00 -0.24 0.00 -0.11
25 10.0111 0.00 -0.12 0.00 -0.19
26 10.0112 0.00 -0.23 0.00 -0.07
27 10.0949 0.00 -0.06 0.00 0.16
28 10.0951 0.00 0.13 0.00 0.05
29 17.2131 0.00 -0.01 0.00 0.23
30 17.2134 0.00 0.42 0.00 -0.20
31 22.1497 0.00 -0.12 0.00 -0.00
32 22.1499 0.00 -0.06 0.00 -0.03
33 22.1500 0.00 0.09 0.00 -0.15
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.
98WS31 quality flag:3 Type: 3:2E 3:2E 3:2E axisobj 39.783 39.783 39.783 ecceobj 0.209 0.209 0.209 incobj 6.727 6.727 6.727 qmin 30.913 30.913 30.913 qmax 48.293 48.292 48.293 amean 39.456 39.456 39.456 amin 39.106 39.105 39.106 amax 39.860 39.860 39.861 emean 0.195 0.195 0.195 emin 0.174 0.174 0.174 emax 0.213 0.213 0.213 imean 6.869 6.870 6.869 imin 6.236 6.236 6.236 imax 7.741 7.741 7.741 excite_mean 0.229 0.229 0.229 fracstop 1.000 1.000 1.000 cjmean 2.992 2.992 2.992 libcent 0 180.5 180.5 180.5 libamp 0 33.5 33.4 33.5 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 189.4 189.4 189.4 kozaiamp 179.9 179.9 179.9