Hi,(adsbygoogle = window.adsbygoogle || []).push({});

I' having an hard time with the following issue.

I've made some routines to calculate the ephemeris from Earth to Neptune with VSOP87C - referred to the mean equinox and ecliptic of date, I supose.

So, the data I receive, is already precessed to the mean equator and ecliptic of any date.

Then, I wrote the code for calculating the position of Pluto, with Pluto95 theory - these coordinates are referred to the mean equinox and ecliptic of J2000 however.

To complicate things, VSOP87 is not in the FK5 frame... And according to Meeus, we must make first the corrections of light time before converting them to FK5.

So my question is: how do get the position of Pluto into the VSOP87 frame (mean equinox and ecliptic of date, no FK5) to perform the calculations?

The same thing happens with the Moon - with ELP82 theory.

I'm really stuck... And I need help with the math in this one...

Kind regards,

CPtolemy

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Problem in generating ephemeris data

**Physics Forums | Science Articles, Homework Help, Discussion**