Variations in the Stellar Luminosity Function. III. a Region in Auriga.

Abstract

view Abstract Citations (6) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Variations in the Stellar Luminosity Function. III. a Region in Auriga. McCuskey, S. W. Abstract An analysis of the galactic structure in Auriga (R.A. 5~~Olm; Dec. +42°) by means of spectra, photo graphic magnitudes, and colors for stars with mpg < 12.5 has yielded the following results: 1. The absorption of photographic light amounts to 1.2 mag. per kiloparsec, beginning at about 20( parsecs from the sun. 2. Density analyses indicate concentrations of B5 and B8-AO stars at 1000 and 1500 parsecs, respec tively. The giants of other spectral classes do not show such concentrations. Detailed density function are given in Table 6. 3. At 100 parsecs the data indicate the same excess of stars with -1 <M < + 1 as found in othe fields (LF1, LF2, LF8), about 0.3 in log 4(M) as compared to the standard van Rhijn luminosity func tion. A corresponding deficiency of 0.3 in log ~(M) for- M > +2 is also present. At distances of 200, 400, and 600 parsecs, the excess of brighter stars is very slight. For stars witi M> +1 a deficiency of 0.4 in log ~(M) relative to the van Rhijn function has been found. 4. Variation of the parameter oo, the dispersion in absolute-magnitude distribution for a given spec tral group, has little effect upon the computed functions, log 48(M). On the other hand, by making th~ mean absolute magnitude, M0, for the dwarf stars 0.5 mag. fainter, the deficiency found for M > +~ relative to the van Rhijn function may be removed. No reasonable reassignment of M0 for the early type stars wiU remove the excess noted for stars with M < +1 Publication: The Astrophysical Journal Pub Date: May 1949 DOI: 10.1086/145145 Bibcode: 1949ApJ...109..414M full text sources ADS | Related Materials (8) Part 1: 1947AJ.....52..155M Part 2: 1947ApJ...106....1M Part 3: 1949ApJ...109..139M Part 5: 1951ApJ...113..672M Part 6: 1952ApJ...115..479M Part 7: 1954ApJ...120..139M Part 8: 1955ApJ...121..643F Part 9: 1956ApJ...123..458M