The early A type stars - Refined MK classification, confrontation with Stroemgren photometry, and the effects of rotation

Abstract

view Abstract Citations (172) References (52) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation Gray, R. O. ; Garrison, R. F. Abstract The MK classification system for the early A-type stars is refined, and a parallel system of standards for the broad-lined stars is introduced. With this improved system, stars may be classified with significantly greater precision than before. It is shown that spectral types in this system are not systematically affected by rotational line broadening. A total of 372 early A-type stars are classified, and a confrontation of these spectral types with Stroemgren photometry reveals a number of systematic photometric effects of rotation. In particular, high v sin i stars are systematically redder than low v sin i stars of the same spectral type, and the beta index is weakened by rotation. It is concluded that precise spectral classification in conjunction with Stroemgren and H-beta photometry can potentially provide a valuable check and input to the theory of the atmospheres of rotating stars. Publication: The Astrophysical Journal Supplement Series Pub Date: December 1987 DOI: 10.1086/191237 Bibcode: 1987ApJS...65..581G Keywords: A Stars; Astronomical Photometry; Early Stars; Stellar Rotation; Stellar Spectra; Classifications; Stellar Atmospheres; Stellar Luminosity; Astrophysics; PHOTOMETRY; STARS: EARLY-TYPE; STARS: ROTATION; STARS: SPECTRAL CLASSIFICATION; STARS: VISUAL MULTIPLES full text sources ADS | data products SIMBAD (373)