Comet coordinates are inaccurate
After the latest update to the new JPL Json format. The coordinates are not accurate when compare to the JPL solution. For example, on 2021.10.21, for comet 15P/Finlay, KStars reports the J2000 RA/DE
RA: 08:55:32 DE: 24:46:31
Whereas JPL reports them as:
RA: 08:43:22 DE: 25:47:42
Checked also against SkyCharts & Stellarium, and they both report coordinates close to the JPL values. It appears that the true anomaly is wrong in KStars. It's reported as 95.605 degrees where as JPL reports 88.155 degrees:
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Initial IAU76/J2000 heliocentric ecliptic osculating elements (au, days, deg.):
EPOCH= 2457083.5 ! 2015-Mar-02.0000000 (TDB) RMSW= n.a.
EC= .7201578442781659 QR= .97589618626998 TP= 2457018.5546788946
OM= 13.77867240695626 W= 347.5524033851874 IN= 6.799388061457817
Equivalent ICRF heliocentric cartesian coordinates (au, au/d):
X= 4.438083791392392E-01 Y= 1.100121685785374E+00 Z= 6.218393882345831E-01
VX=-1.272767198156648E-02 VY= 1.190477093157128E-02 VZ= 7.300398457646802E-03
Comet physical (GM= km^3/s^2; RAD= km):
GM= n.a. RAD= n.a.
M1= 14.9 M2= n.a. k1= 8.25 k2= n.a. PHCOF= n.a.
Comet non-gravitational force model (AMRAT=m^2/kg;A1-A3=au/d^2;DT=days;R0=au):
AMRAT= 0. DT= 0.
A1= 2.309681922197E-9 A2= -2.319974638522E-10 A3= 2.337836325169E-9
Standard model:
ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808
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Date__(UT)__HR:MN R.A.__(a-apparent)__DEC T-mag N-mag hEcl-Lon hEcl-Lat r rdot Tru_Anom
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$$SOE
2021-Oct-21 00:00 08 43 22.59 +25 47 42.0 17.593 n.a. 89.5995 6.5949 1.664881117229 16.3553686 88.1552
2021-Oct-22 00:00 08 44 41.02 +25 46 51.9 17.611 n.a. 90.0638 6.6080 1.674328335578 16.3590802 88.6165
2021-Oct-23 00:00 08 45 57.29 +25 46 08.3 17.629 n.a. 90.5230 6.6205 1.683777387367 16.3617070 89.0728
2021-Oct-24 00:00 08 47 11.41 +25 45 31.3 17.647 n.a. 90.9771 6.6325 1.693227656217 16.3632843 89.5239
2021-Oct-25 00:00 08 48 23.36 +25 45 01.1 17.664 n.a. 91.4261 6.6440 1.702678545851 16.3638464 89.9700
2021-Oct-26 00:00 08 49 33.13 +25 44 38.1 17.681 n.a. 91.8702 6.6549 1.712129479474 16.3634266 90.4112
2021-Oct-27 00:00 08 50 40.69 +25 44 22.4 17.698 n.a. 92.3095 6.6653 1.721579899169 16.3620570 90.8475
I tried to troubleshoot this. Why would the true anomoly be wrong? it depends on mean anomaly which is calculated as this:
dms m = dms(double(360.0 * (deltaJDP) / P)).reduce();
Which depends on deltaJDP which the JD of the perihelion passage.
@vboettcher @asimha @murveit Do you have any ideas on what could be causing this?