Table information for 'ppmxl.usnocorr'


Table Description: Corrections between USNO-B1 and PPMXL on a grid of degrees, obtained by substracting PPMXL from USNO in cones of radius sqrt(2)/2 degrees around the given center position.

This table is available for ADQL queries and through the TAP endpoint.

Resource Description:

PPMXL is a catalog 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 to the ICRS as represented by PPMX. This service additionally provides improved proper motions computed according to Vickers et al, 2016 (2016AJ....151...99V).

For a list of all services and tables belonging to this table's resource, see Information on resource 'The PPMXL Catalog'

Citing this table

This table has an associated publication. If you use data from it, it may be appropriate to reference 2010AJ....139.2440R (ADS BibTeX entry for the publication) either in addition to or instead of the service reference.

To cite the table as such, we suggest the following BibTeX entry:

  title={The {PPMXL} Catalog},
  author={Röser, S. and Demleitner, M. and Schilbach, E. and Vickers, J. J.},
  howpublished={{VO} resource provided by the {GAVO} Data Center},
  doi = {10.21938/puTViqDkMGcQZu8LSDZ5Sg}

Resource Documentation

To query this data, you can use

You can retrieve also the whole data set as a gzipped text file (43.5 GiB) from the download service. The columns in the text file are in database order as documented in the table info in DB order with columns separated by vertical bars ("|").

If you run DaCHS yourself, you can use a C booster kindly provided by Hailong Zhang. Instructions on usage are at the head of the file.

David Tholen kindly provided code to convert this into a collection of files for easy consumption by FORTRAN programs.

In 2016, John Vickers provided a global correction of the PPMXL proper motions based on extragalactic objects (2016AJ....151...99V). The results are given in the vickers_pmra and vickers_pmde columns. The coefficients we used are available at pmr-coefficients.csv and pmd-coefficients.csv. When used with the Code we actually used to compute the corrected values (adding healpix interpolation to the upstream from, these files have to be renamed pmr.csv and pmd.csv, respectively.


Sorted by DB column index. [Sort alphabetically]

NameTable Head DescriptionUnitUCD
nob N Number of objects the correction is based on N/A meta.number
alpha Center RA Center for field, RA deg pos.eq.ra;meta.main
delta Center Dec Center for field, Dec deg pos.eq.dec;meta.main
d_alpha PPMXL-USNO, RA Correction PPMXL-USNO in alpha (Epoch 2000.0) deg pos.eq.ra;arith.diff
d_delta PPMXL-USNO, Dec Correction PPMXL-USNO in delta (Epoch 2000.0) deg pos.eq.dec;arith.diff
d_pmalpha PPMXL-USNO, PM RA Correction PPMXL-USNO in proper motion alpha*cos(delta) deg/yr;pos.eq.ra;arith.diff
d_pmdelta PPMXL-USNO, PM Dec Correction PPMXL-USNO in delta deg/yr;pos.eq.dec;arith.diff

Columns that are parts of indices are marked like this.


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