Photoelectric Magnitudes and Colors of Extragalactic Nebulae
1937; IOP Publishing; Volume: 86; Linguagem: Inglês
10.1086/143865
ISSN1538-4357
AutoresJoel Stebbins, A. E. Whitford,
Tópico(s)Astronomical Observations and Instrumentation
Resumoview Abstract Citations (28) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Photoelectric Magnitudes and Colors of Extragalactic Nebulae Stebbins, Joel ; Whitford, Albert E. Abstract The magnitudes of 165 extragalactic nebulae down to magnitude 15 have been measured with the photoelectric cell; of these, 112 have also been measured for color. The magnitudes, based upon the Harvard visual system, are reduced to the inter- national scale and give a correction of -0.1 to the photographic magnitudes of the Harvard Survey at magnitudes 11-13. The colors of the nebulae are referred to the color scale of dwarf stars. The nebulae of Hubble's types E, Sa, and Sb are nearly uniform in color; those of type Sc are more varied, owing presumably to the presence of giant stars. There is a residual color excess for the nebulae, E= +0.14 mag. on the international scale, which is possibly due to selective absorption within the nebulae themselves. There is no dependence of color upon magnitude such as would be caused by selective absorption in intergalactic space. From the colors of nebulae, globular clusters, and B stars it is found that the ratio of selective to total space absorption is smaller in high than in low galactic latitude. The sun is assumed to be immersed in a dark layer of small selectivity near the galactic plane, while clouds of greater selectivity are present in nearly all directions along that plane but not immediately about the sun Publication: The Astrophysical Journal Pub Date: October 1937 DOI: 10.1086/143865 Bibcode: 1937ApJ....86..247S full text sources ADS | Related Materials (1) Reprint: 1937CMWCI.577....1S
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