C2A can read the PPMXL catalogue (http://vo.uni-hd.de/ppmxl). PPMXL is a catalogue of positions, proper motions, 2MASS- and optical photometry of 900 million stars and galaxies, aiming to be complete down to about V=20 full-sky. It is the result of a re-reduction of USNO-B1 together with 2MASS.
It is not necessary to compile the PPMXL catalogue. C2A directly reads the native format. The original catalogue can be downloaded from the CDS site at ftp://cdsarc.u-strasbg.fr/pub/cats/I/317/. Caution, the catalogue is delivered under the form of 720 files representing more than 38 GB of data. C2A is also able to read the PPMXL binary version of the catalogue which has been compiled by Dave Herald in the scope of his occultation prediction work.
You select this catalogue as the current catalogue through the Stars tab of the Options dialogue box, or by SHIFT-right-clicking on the map. You can choose to display either of the magnitude bands J, H, Ks, b1, b2, r1, r2 or i by clicking the Advanced options... button on the Stars tab of the Options dialogue box.
The information associated with each star in the catalogue is as follows (for the full textual version of the catalogue):
- the right ascension for the epoch 2000,
- the declination for the epoch 2000,
- position errors,
- the proper motion,
- errors on the
proper motion,
- the magnitude in
the bands J, H, Ks (all from 2MASS) and b1, b2, r1, r2 and i (from USNO-B) when they exist,
- a set of flags specific to the PPMXL catalogue