Selection on V magnitudes or B-V colour index

The command gk and standard options -gt -lt -i are used to perform selection on the V magnitudes and B-V colours. One needs to specify on which parameter the selection will be made, v or b-v and give the lower (-gt), upper (-lt) and bracketing (-i) limiting values.

Example:

  1. gk v -lt 11.5 selects the stars with V < 11.5
  2. gk v -i 11.5 12. selects the stars with 11.5 < V < 12.