  Through the analysis and interpretation of newly obtained and of literature
data we have clarified the nature of poorly investigated IRAS point sources
classified as late type stars, belonging to the Byurakan IRAS ~Stars catalog.
From medium resolution spectroscopyof 95 stars we have strongly revised 47
spectral types and newly classified 31 sources. Nine stars are of G or K types,
four are N carbon stars in the Asymptotic Giant Branch, the others being M type
stars. From literature and new photometric observations we have studied their
variability behaviour. For the regular variables we determined distances,
absolute magnitudes and mass loss rates. For the other stars we estimated the
distances, ranging between 1.3 and 10~kpc with a median of 2.8~kpc from the
galactic plane, indicating that BIS stars mostly belong to the halo population.
