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Title: Precise rotation rates for five slowly rotating A stars

Projected rotation rates of five early A-type slowly rotating stars are measured spectroscopically to a precision of 0.2 km s{sup –1}. A detailed Fourier analysis is done, as well as a comparison of profiles directly. Macroturbulence is needed in addition to rotation to reproduce the profile shapes. An upper limit of ≲2 km s{sup –1} is placed on the microturbulence dispersion. Small unexplained differences between the models and the observations are seen in the sidelobe structure of the transforms. The v sin i results are: α Dra, 26.2; θ Leo, 22.5; α CMa A, 16.7; γ Gem A, 10.7; o Peg, 6.0 km s{sup –1}. These stars are suitable as standards for measuring rotation using less fundamental methods.
Authors:
 [1]
  1. Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)
Publication Date:
OSTI Identifier:
22340309
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 147; Journal Issue: 4; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; ATMOSPHERES; COMPARATIVE EVALUATIONS; DISPERSIONS; FOURIER ANALYSIS; ROTATION; SPECTROSCOPY; STARS; TURBULENCE