A Spectropolarimetric View on the Nature of the Peculiar Type I SN 2005hk

• Published in: The Astrophysical journal 2010-10, Vol.722 (2), p.1162-1174
• Main Authors: Maund, Justyn R, Wheeler, J. Craig, Wang, Lifan, Baade, Dietrich, Clocchiatti, Alejandro, Patat, Ferdinando, Höflich, Peter, Quinn, Jason, Zelaya, Paula
• Format: Article
• Language: English
• Subjects: Astronomy; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ATMOSPHERES; BINARY STARS; DWARF STARS; Earth, ocean, space; ERUPTIVE VARIABLE STARS; Exact sciences and technology; IONIZATION; LUMINOSITY; OPTICAL PROPERTIES; PHOTOSPHERE; PHYSICAL PROPERTIES; POLARIZATION; SOLAR ATMOSPHERE; STARS; STELLAR ATMOSPHERES; SUPERNOVAE; VARIABLE STARS; WHITE DWARF STARS
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/722/2/1162

We report two spectropolarimetric observations of SN 2005hk, which is a close copy of the 'very peculiar' SN 2002cx, showing low peak luminosity, slow decline, high ionization near peak, and an unusually low expansion velocity of only about 7000 km s-1. Further to the data presented by Chornock et al., at --4 days before maximum, we present data of this object taken on 2005 November 9 (near maximum) and November 23 (+ 2 weeks) that show the continuum and most of the spectral lines to be polarized at levels of about 0.2%-0.3%. At both epochs the data correspond to the Spectropolarimetric Type D1. The general low level of line polarization suggests that the line-forming regions for most species observed in the spectrum have a similar shape to that of the photosphere, which deviates from a spherical symmetry by