We analyze spectra of 44 emission line stars detected in a low resolution optical spectroscopic survey of the galactic open cluster NGC 6871 .
The survey of 1217 stars is complete to V = 14.9 and includes stars with V < 16.5 between the zero age main sequence ( ZAMS ) and the 10 ^ { 7 } yr pre-main sequence ( PMS ) isochrone .
Of the 44 emission line stars in this survey , 28 show obvious emission in H \alpha and 16 have weak H \alpha absorption ( compared to H \gamma ) .
We use the reddening to separate foreground and background stars from the cluster members ; the position in the HR diagram ( HRD ) or the presence of forbidden emission lines ( [ NII ] , [ SII ] ) then yields the evolutionary status of the emission line stars .
A comparison of the H \alpha spectral index distribution in NGC 6871 with the distribution of young stars in the Taurus-Auriga molecular cloud indicates that the late type PMS stars in our sample may be weak line T Tauri stars ( wTTs ) .
Many of these stars show [ SII ] ( 36 \% ) and [ NII ] ( 45 \% ) emission .