Generate star charts based on Hipparcos/Tycho data

Star database

• Coordinates: should be transformed to astropy.coordinates. Precession not really needed.
• Database: should be converted to astroquery
• Geometry: SphericalPoint, HourAngle, DMSAngle should be converted to astropy.coordinates.
• Projections: should be adapted to use astropy.coordinates
• Constellations; precession to B1875 can be done in astropy (see get_constellation function). Rest of functionality in

Dependencies:

• libspatialindex
• xelatex