## Changes Introduced in V8.7.0

The following describes the most significant changes which occurred in the AST library between versions V8.6.3 and V8.7.0:

1. The RegionRegion class has a new method called astGetRegionDiscastGetRegionDisc, which returns the centre and radius of a disc that just encloses a 2-dimensional Region.

2. A new subclass of Region called “MocMoc” has been added. A Moc describes an arbitrary region of the sky in the form of a set of HEALPix cells.

3. The BoundedBounded attribute defined by the Region class is now always non-zero for Regions defined within a SkyFrameSkyFrame, regardless of whether the Region has been negated. Previously, it was non-zero only if the Region had not been negated. Note, this change only affects Regions defined within SkyFrames.