item   name  unit    description
-------------------------------------------------------------------------
  1    srcid         Gaia source ID
  2    rag   deg     Gaia RA  at epoch 2015.0  (from DR1)
  3    dcg   deg     Gaia Dec at epoch 2015.0
  4    erg   mas     Gaia DR1 position error RA  at epoch 2015.0
  5    edg   mas     Gaia DR1 position error Dec at epoch 2015.0
  6    flg           1 = TGAS,  2 = other UCAC-Gaia star, 3 = other NOMAD
  7    nu            number of images used for UCAC mean position
  8    epu   yr      mean UCAC epoch (after 1997.0)
  9    ira   mas     mean UCAC RA  at epu epoch on Gaia reference frame
 10    idc   mas     mean UCAC Dec at epu epoch on Gaia reference frame
 11    pmur  mas/yr  proper motion RA*cosDec (UCAC-Gaia)
 12    pmud  mas/yr  proper motion Dec       (UCAC-Gaia)
 13    pmer  mas/yr  formal error of UCAC-Gaia proper motion RA*cosDec
 14    pmed  mas/yr  formal error of UCAC-Gaia proper motion Dec
 15    gmag  mag     Gaia DR1 G magnitude      
 16    umag  mag     mean UCAC model magnitude 
 17    rmag  mag     NOMAD photographic R mag  
 18    jmag  mag     2MASS J magnitude         
 19    hmag  mag     2MASS H magnitude         
 20    kmag  mag     2MASS K magnitude         
-------------------------------------------------------------------------