2011-02-08 (MD): Fixed a bug that would give bogus V errors. Also, warning at this
point: the Ru magnitudes result from extrapolating 2MASS magnitudes.
Where those are missing or bad, the Ru magnitudes are bad, too.
2011-06-06 (MD): Silent update: 7836 objects had Ru magnitudes computed although at
least one 2MASS magnitude was NULL. In consequence, these objects had
large negative Ru magnitudes. These erroneous Ru magnitudes are now
NULL.
Description
PPM-Extended (PPMX) is a catalogue of 18 088 919 stars on the ICRS
system containing astrometric and photometric information. Its
limiting magnitude is about 15.2 in the GSC photometric system.
PPM-Extended (PPMX) is a catalogue of 18 088 919 stars on the ICRS
system containing astrometric and photometric information. Its
limiting magnitude is about 15.2 in the GSC photometric system.