Interstellar extinction in the Orion association
1968; IOP Publishing; Volume: 152; Linguagem: Inglês
10.1086/149607
ISSN1538-4357
Autores Tópico(s)Astro and Planetary Science
Resumoview Abstract Citations (192) References (36) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Interstellar extinction in the Orion association. Lee, T. A. Abstract Photoelectric photometry of 196 members of I Orionis was obtained in an effort to determine the wave- length dependence of interstellar extinction throughout the association. Regional extinction laws were calculated from the color excesses of individual stars in localized areas. Equivalent monochromatic laws were also computed. Two areas of the association, the center of the Orion Nebula and the east "Belt" region near ~ Orionis, exhibit significantly "non-normal" extinction. The anomalies in both cases are a steep infrared extinction gradient and a high ratio of total to selective absorption. In the east Belt region, R _ 5.5, whereas near 0' Orionis, R »= 5 5. The anomaly in the Orion Nebula is confined to the center of the nebula, within 15' of 01 Orionis Efforts to explain the strong infrared radiation of the early-type stars in this region in terms other than interstellar extinction have been unsuccessful; circumstellar emission is possible, but cannot account for the entire effect. In all cases, the stars in I Orionis showing decidedly non-normal extinction laws are closely associated with bright nebulosity and are of the earliest spectral types. Yet similar-type stars in the same region often exhibit no such anomalies. The data give additional credence to the suggestion that the obscuring matter is modified by hot, young stars; in fact, several of the Orion extinction laws closely resemble those resulting from bimodal distributions of particles of different characteristic sizes Publication: The Astrophysical Journal Pub Date: June 1968 DOI: 10.1086/149607 Bibcode: 1968ApJ...152..913L full text sources ADS | data products SIMBAD (193) GCPD (1)
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