The by Halpha data are used to search for Be stars in open clusters. The detection is
made in a (b-y, y-Halpha) plane. These data are also used to build the
color-magnitude diagram in the Strömgren system.
Record structure
| No | : | Star number |
|---|---|---|
| Ref | : | Reference |
| V | : | V magnitude (y) |
| b-y | : | b-y colour index |
| yHa | : | y-Halpha index |