SIMBAD references

One hundred eighty-five mostly OB and some early A-type stars are detected at 1640 Å with the ultraviolet telescope Glazar aboard the Mir space station in an area of about 8 deg² in the direction toward the stellar association Cen OB2. The limiting stellar magnitude m₁₆₄₀ of the observations is about 8.5 mag. Stellar associations at distances of 360, 850, 1500, 2300, 2700, 4000, and 6700 pc are detected by the study of the space distribution of 111 of the observed stars with known spectral types. It was shown that the cluster IC 2944 is located at a distance of 2200 pc. It is suggested that the extinction of emission of stars in the content of the cluster is due to small dust clouds or even to circumstellar dust shells. It is shown also that the dust matter is practically absent in the space between stellar associations and that the extinction of some stars within stellar associations is caused by relatively small dust clouds, in which the stars are embedded. Two of the detected stars, HD 101316 and HD 101967, are of relatively late spectral types and therefore probably have hot dwarf or subdwarf companions.