Updated about 12 years ago by 
GSkyDir¶
The GSkyDir class implements a direction on the sky, given either in equatorial (FK5 J2000) or Galactic coordinates.
The coordination transformation (a simple rotation) is checked in test_GSky.py in Test.test_fk5_to_galactic().
The gammalib results agree with PyAST within 10 milli-arcseconds for the whole sky.
Once we consider adding astronomical time and coordinate functionality to gammalib, this might be a useful reference:
https://github.com/astropy/coordinates-benchmark