Is there a data online for the time of perihelion of Neptune between 2000AD and 3000AD? I need values in Julian Date (JD).

I tried using HORIZONS Web interface, but it won't generate ephemeris for Neptune after a certain calendar date.


  • 3
    $\begingroup$ Yes, Horizons only goes up to 2050 for Neptune. ssd.jpl.nasa.gov/eph_spans.cgi?id=A But try the Neptune barycenter, which goes upto 9999. $\endgroup$
    – PM 2Ring
    Jan 22, 2021 at 3:02
  • $\begingroup$ Do you have a link? I don't know what I'm looking for. $\endgroup$
    – posfan12
    Jan 22, 2021 at 3:19
  • 2
    $\begingroup$ Sorry, I was busy figuring it out myself. :) You need to use planet command code 8 not 899. It seems to work ok. I just tested it for 4000 AD. I got slightly confused because the JD of Tp changes, but I guess that's because the orbit is precessing. I don't have a link that explains what to do, apart from the Horizons docs. But I could give you a link that generates the ephemeris. What time step do you want? $\endgroup$
    – PM 2Ring
    Jan 22, 2021 at 3:50
  • 2
    $\begingroup$ This link gives you the Neptune barycenter orbital elements, including Tp, the time of perihelion passage, from 2000 AD to 3000 AD, with a step size of 10 years. $\endgroup$
    – PM 2Ring
    Jan 22, 2021 at 4:29


You must log in to answer this question.

Browse other questions tagged .