Document Type
Article
Publication Date
8-25-2014
Description
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.
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
Copyright Statement
Reproduced with permission from Astronomy & Astrophysics, Copyright © ESO 2014.