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Spectroscopic parallaxes of MAP region stars from UBVRI, DDO, and uvbyH-beta photometryThis paper presents the results of spectral type and luminosity classification of reference stars in the Allegheny Observatory MAP parallax program, using broadband and intermediate-band photometry. In addition to the use of UBVRI and DDO photometric systems, the uvbyH-beta photometric system was included for classification of blue (B - V less than 0.6) reference stars. The stellar classifications made from the photometry are used to determine spectroscopic parallaxes. The spectroscopic parallaxes are used in turn to adjust the relative parallaxes measured with the MAP to absolute parallaxes. A new method for dereddening stars using more than one photometric system is presented. In the process of dereddening, visual extinctions, spectral types, and luminosity classes are determined, as well as a measure of the goodness of fit. The measure of goodness of fit quantifies confidence in the stellar classifications. It is found that the spectral types are reliable to within 2.5 spectral subclasses.
Document ID
19910029672
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Persinger, Tim
(Allegheny Observatory Pittsburgh, PA, United States)
Castelaz, Michael W.
(Allegheny Observatory Pittsburgh, PA, United States)
Date Acquired
August 14, 2013
Publication Date
November 1, 1990
Publication Information
Publication: Astronomical Journal
Volume: 100
ISSN: 0004-6256
Subject Category
Astronomy
Accession Number
91A14295
Funding Number(s)
CONTRACT_GRANT: NSF AST-86-17642
CONTRACT_GRANT: NAGW-1270
Distribution Limits
Public
Copyright
Other

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