CD-50 9197 , the SIMBAD biblio

This investigation presents a study of the Galactic structure toward the Norma section of the Milky Way. The field studied is located between 325° and 335° Galactic longitude and to 8° Galactic latitude. New observations in the system are combined with all data currently available to collate a sample of 130 O and B stars. A uniform procedure is applied to obtain the color excesses and stellar distances for all of the stars in the sample. The sample is magnitude limited to about and contains the brightest stars of the open clusters NGC 6087 and Ly 6, the field 2158 of Loden, the OB association Nor OB1, and stars located in the directions of R 103 and R 105. The intrinsically luminous stars in the field studied appear to be closer to the Sun than it has previously been thought. At about 860 pc, the majority of the stars in the sample delineate a segment consistent with the location of the Sagittarius-Carina arm as suggested in the four-arm model representation of the grand design of the Milky Way. A small part of the sample defines the near edge of the Scutum-Crux arm at about 1.75 kpc.