The Space Distribution of Stars at Galactic Latitude -30 .

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Space Distribution of Stars at Galactic Latitude -30 . Philip, A. G. Davis Abstract University of New Mexico.-An objective prism survey in Pegasus at b"--290, lII~76o, in a 33.2 square degree region has been undertaken to determine the space density function and the luminosity function for stars at intermediate galactic latitudes. This work is part of a larger survey which will provide the basis for a crosssectional study of the galactic spiral arm in the `Cygnus direction. The objective prism employed has a dispersion of 280 A/mm at H~~. For stars later than ~O, luminosity classes I, III, and V can be distinguished. The survey is complete to a B magnitude ~of 12.2. A photoelectic sequence of 86 stars was observed `at Kitt Peak National Observatory and McDonald `Observatory to provide photometric standards in the UBV system for the calibration of B magnitudes and `the determination of interstellar absorption. In the `first kiloparsec, the absorption was 0.66 mag. in the `blue and 0.50 in the visual. The space density of main sequence stars earlier ft~an class GO falls off rapidly with increasing dis- tance. At 600 pc from the sun it has fallen to 0.1 of the density at 200 pc. G dwarf stars were found to have a constant density to the depth of the survey. The space density of late-type giant stars at 600 pc is about 0.5 that at 200 pc. The luminosity function at 200 and 400 pc, equivalent to a distance of 100 and 200 pc below the plane of the galaxy, shows a dip at MB=2.5 relative to the shape of the van Rhijn luminosity function of the solar neighborhood. Publication: The Astronomical Journal Pub Date: 1965 DOI: 10.1086/109523 Bibcode: 1965AJ.....70Q.146P full text sources ADS |