Frequently asked questions
Swiss Ephemeris > Printable Ephemeris
is the difference between GMT and UT?
There is no difference between GMT (Greenwich Mean Time) and UT (Universal Time), GMT is just an older name.
does Delta T = [number] mean?
Delta T indicates the difference between UT and TDT (Terrestrial Dynamic Time), which used to be called 'Ephemeris time' in the last century. While UT is not a uniform time scale (it is occasionally adjusted, due to irregularities in the Earth's rotation), TDT is a uniform time scale which is needed as an argument for mathematical theories of celestial movements.
you offer a printable sidereal ephemeris?
Yes, we have. You can create one for any time period you like.
Please go to extended chart selection, ephemeris.
Select the type of ephemeris, the start year and the zodiac.
In the screen shot:
ephemeris for 10 years,
start date 2016,
You get a PDF file which you can save on your computer.
- Trying to
one of the ephemerides for new planets / asteroids, the page gets
Why is that?
This is most likely a bug in the Internet Explorer. It displays long text data tables very slowly. You may have to wait up to 3 minutes for the page to display, and it finally will.