second conference on co-ordination of galactic research

absolute magnitudes absorption according accurate appear areas associations Astr Astroph blue brighter centre Cepheids changes classification Clouds color complete component concentration conference density derived determined diagram direction discussed disk dispersion distance distribution estimate excess extending extremely faint field formed function galactic galactic plane Galaxy giants globular clusters groups halo hydrogen important indicated interest interstellar km/sec known limit lines long-period luminosity main sequence mass maximum means measured method Morgan motion neutral hydrogen objects observations Observatory obtained optical parallaxes periods photo-electric photographic photographic magnitude photometric photometric system plates population possible present probably problem proper motions radial velocities radio recently References regions relation reported rotation RR Lyrae Schmidt selected separation similar spectral spectral type standards stars stellar survey tion variables various