We use the US Naval Observatory USNO-SA2.0 catalog
For catalogue acces we use
Doug Mink's fine scat program.
Notes:
Unless explicitly specified, we use R-band magnitudes.
The "selection criteria" option changes the star selection strategy:
all gives back all stars
Nearest gives the nearest star only
Brightest gives the brightest star
Weighted gives the star with the highest value of
a score proportional to the inverse of the distance and to the
magnitude (nearer and brighter => better).