Dawn--Pope Gregory XIII has approved the re-organised Calendar of 1582 to be the Authoritative one for our Church. The idea that the Earth revolves around the Sun has been approved by him and used in the calculations for that calendar. This is a historical truth.
Although it is rare for me to use wikipedia as a source, in this case it is appropriate.
http://en.wikipedia.org/wiki/Ludwig_von_PastorSee vol19 for re-organisation of Calendar and v 25 for first Galileo case: see contents of each vol for relevant pages.
I tend to pay attention to the Pope even when he is not speaking ex cathedra in matters of faith and morals.
It is interesting that the two Protestants that agreed with Copernicus that the Earth revolves around the Sun(Kepler and Osiander) also approved of the new calendar. While Luther, Calvin, Beza, Melanthon, Bacon, and King James among others all believed that the Sun revolves around the Earth and rejected the Authority of the Gregorian Calendar.
Dawn--do you accept the authority of the Roman Gregorian Calendar? The point here is that one cannot accept the Greg Calendar and reject the idea that the Earth revolves around the Sun because they are one and the same system. It might help to read the first 11 chaps of book 1 in De Revolutionibus