Some Characteristics of the B and a Stars in the Upper Scorpius Complex
1967; IOP Publishing; Volume: 147; Linguagem: Inglês
10.1086/149090
ISSN1538-4357
Autores Tópico(s)Astronomy and Astrophysical Research
Resumoview Abstract Citations (217) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Some Characteristics of the B and A Stars in the Upper Scorpius Complex Garrison, R. F. Abstract More accurate spectral classifications from new McDonald spectrograms are given for seventy-five Henry Draper B( B9 stars in the region of the Upper Scorpius part of the Scorpio-Centaurus association, for which photometry by Hardie and Crawford is available. Classifications and photometry are also presented for the lID A0-F2 stars in the inner region defined by the asterism formed by a Sco, Sco, 22 Sco, and p Oph. A narrow main sequence is found for the B2-F0 members of this inner region. Of special interest is the presence of peculiar Sr ii stars in the inner region. These are probably members of the association, and their presence suggests that such stars occur in an early stage of evolution rather than a later one. In the larger Upper Scorpius region, a number of other peculiar stars are found which are probably association members. A pronounced lack of agreement is found between many of the present spectral types and those derived from narrow-band photometry. For certain B7-B9 stars, located above the main sequence, the latter method gives, systematically, much higher temperatures. These discrepancies indicate that two- dimensional spectral types continue to be of astrophysical importance; their value is especially great when combined with accurate narrow-band photometry. Publication: The Astrophysical Journal Pub Date: March 1967 DOI: 10.1086/149090 Bibcode: 1967ApJ...147.1003G full text sources ADS | data products SIMBAD (139) GCPD (1)
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