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A photometric study of the Orion OB 1 association. 2: Photometric analysisThe procedures adopted for analysis of photometric data in terms of color excesses, intrinsic color indexes, absolute visual magnitudes, and rotational-velocity effects are discussed in detail for Orion association B-, intermediate (I)-, and AF-type stars. The effects of the nebular environment and a comparison of various calibrations of Balmer-line and four-color indexes are considered for the determination of individual absolute magnitudes for B-type stars. When absolute magnitudes of stars in the region of the Orion Nebula are determined from the beta index, emission mechanisms appear to spuriously brighten them. A detailed comparison of absolute magnitudes derived from Balmer-line indexes and MK spectral-type calibrations is presented. The data are also examined with regard to the effects of polarization and infrared excesses. The results suggest a complex combination of intracluster and circumstellar origins for these processes.
Document ID
19770004993
Acquisition Source
Legacy CDMS
Document Type
Preprint (Draft being sent to journal)
Authors
Warren, W. H., Jr.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Hesser, J. E.
(Cerro Tololo Inter-American Observatory La Serena, Chile)
Date Acquired
September 3, 2013
Publication Date
October 1, 1976
Subject Category
Astronomy
Report/Patent Number
NASA-TM-X-71217
X-671-76-237
Accession Number
77N11936
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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