Further Information Concerning the Atlas for Objective Prism Spectra.
W. C. Seitter · The Astronomical Journal · 1967
The first part of the spectral atlas announced 3 yr ago is to be published early this fall. It will contain the information pertaining to the dispersion of 240 A/mm. Parts 2 and 3 for dispersions 645 and 1280 A/mm will follow next year. Sample prints are shown of (1) A detailed chart of a Cyg A2Ia. (2) A chart of 09V to B5V stars. The first chart (one of four showing A, B, G, and K stars) aims at completeness in listing all lines visible between 3400 and 9000 A on spectra with a dispersion of 240 A/mm at Hw and a wavelength resolution of 2-5 A at H~ for 2-3" image size. Identifications of lines are given in order of increasing excitation or ionization potentials. The second chart is one of 24 charts giving all spectral types within a given luminosity class that are listed in the Johnson-Morgan catalogue of 1953. All major features are identified. Thirty-two additional charts compare the different luminosity classes at a given spectral type. Luminosity indicators are shown in schematic spectra. Their estimated intensity ratios with respect to major features are given. A series of tables lists all lines measured on any of the approximately 350 photographs of the 160 types represented in the atlas. They are intended to show with what accuracy the various features are measured and with what certainty the identifications may be made.