We report the discovery of new pre-main sequence ( PMS ) stars in the Lagoon Nebula ( M8 ) at a distance of 1.25 kpc , based on intermediate resolution spectra obtained with the Boller & Chivens spectrograph at the 6.5 m Magellan I telescope ( Las Campanas Observatory , Chile ) .
According to the spectral types , the presence of emission lines and the lithium \lambda 6708 absorption line , we are able to identify 27 classical T Tauri stars , 7 weak-lined T Tauri stars and 3 PMS emission objects with spectral type G , which we include in a separated stellar class denominated “ PMS Fe/Ge class ” .
Using near-infrared photometry either from 2MASS or from our own previous work we derive effective temperatures and luminosities for these stars and locate them in the Hertzsprung-Russell diagram , in order to estimate their masses and ages .
We find that almost all of our sample stars are younger than 3 \times 10 ^ { 6 } years and span over a range of masses between 0.8 and 2.5 M _ { \odot } .
A cross-correlation between our spectroscopic data and the X-ray sources detected with the Chandra ACIS instrument is also presented .