Spectropolarimetry, a technique that determines the fraction of light from a polarized source as a function of wavelength can help astronomers determine the geometry of a supernova explosion. The spectrum of these objects are a combination of an underlying continuum and superposed absorption and/or emission features. Low degrees of polarization (~0.2-0.3%) across the continuum with higher detections across some spectral features (~1-2%) indicate that a particular explosion is relatively spherical in nature, but some of the ejecta has been expelled in a clumpy manner. It is possible to determine how the star exploded by comparing the evolution of this polarization over time to theoretical explosion models. We present the multi-epoch observations of 2014J, a supernova with very little overall asymmetry as revealed by low continuum polarization measurements. However, a polarization detection of ~0.5% across the singly-ionized silicon spectral feature indicates that this particular ion has a more complex geometry.
Porter, Amber L.; Leising, Mark D.; Williams, Grant; Milne, Peter; Smith, Paul; and Smith, Nathan, "Determining the shape of a supernova explosion" (2015). Graduate Research and Discovery Symposium (GRADS). 155.