RA/DEC in Fits not in J2000

[Ruediger]

It looks like the RA/DEC coordinates in FIT’s header are not stored in J2000 epoch but in JNOW which leads to a persistent error when re-using the fits (e.g. plate solving), which exclusively work with J2000. For example ASTAP gives a persistent offset).

Solution: Store the J2000 coordinates, which is usually done.

Thank you!

[Dale Ghent]

Hi Ruediger, I’ve taken a look at this and have a fix that precesses FITS keywords and XISF image properties from JNOW to J2000, as well as adds the EQUINOX keyword to declare the equatorial equinox that is in use (eg; EQUINOX: 2000.0)

I will be testing this some more and it should slide into the current 1.10 beta cycle as a fix when completed. I’m also taking a look at how we format real numbers (floats) in textual format in the keyword values.

[Ruediger]

Hi Ghent!

Thank you very much! Much appreciated!

[Stefan B]

i've added the transformation to j2000 into the fits and xisf headers. it is available in 1.10 beta 15