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Article
Evidence of a Mira-like tail and bow shock about the semi-regular variable V CVn from four decades of polarization measurements.
Astronomy & Astrophysics (2014)
  • Hilding R. Neilson, East Tennessee State University
  • Richard Ignace, East Tennessee State University
  • Beverly J. Smith, East Tennessee State University
  • Gary Henson, East Tennessee State University
  • Alyssa M. Adams, Arizona State University
Abstract
Polarization is a powerful tool for understanding stellar atmospheres and circumstellar environments. Mira and semi-regular variable stars have been observed for decades and some are known to be polarimetrically variable, however, the semi-regular variable V Canes Venatici displays an unusually large, unexplained amount of polarization. We present ten years of optical polarization observations obtained with the HPOL instrument, supplemented by published observations spanning a total interval of about forty years for V CVn. We find that V CVn shows large polarization variations ranging from 1 - 6%. We also find that for the past forty years the position angle measured for V CVn has been virtually constant suggesting a long-term, stable, asymmetric structure about the star. We suggest that this asymmetry is caused by the presence of a stellar wind bow shock and tail, consistent with the star's large space velocity.
Keywords
  • stars: mass-loss,
  • techniques: polarimetric,
  • circumstellar matter,
  • stars: individual: V CVn,
  • stars: AGB and post-AGB
Publication Date
August 25, 2014
DOI
http://dx.doi.org/10.1051/0004-6361/201424037
Publisher Statement
Reproduced with permission from Astronomy & Astrophysics, Copyright © ESO 2014.
Citation Information
Hilding R. Neilson, Richard Ignace, Beverly J. Smith, Gary Henson, and Alyssa M. Adams. "Evidence of a Mira-like tail and bow shock about the semi-regular variable V CVn from four decades of polarization measurements." Astronomy & Astrophysics 568 (2014): A88.
DOI: 10.1051/0004-6361/201424037
Available at: http://works.bepress.com/richard_ignace/9