Speaker
Description
In the last years great progress has been achieved on our understanding of supernovae (SNe). However, there are still many unknowns on the nature of the progenitor systems, their environment, and the physics behind the explosions. An important approach in this context is to use polarimetric data, which are scarce compared to spectrophotometry and can reveal essential information on the geometry of the explosions and the dust along the line of sight. In this talk, I will introduce the efforts conducted by a team from the University of Cadiz, the Center for Astrophysics and Gravitation (Lisboa) and the Institute of Space Sciences (Barcelona) to increase the number of imaging polarimetry data of SNe using the Calar Alto Faint Object Spectrograph (CAFOS). Specifically, I will present BVRI polarimetry of a few type II SNe, and discuss the possible mechanisms giving rise to the measured polarization. For example, SN 2017eaw shows a polarization degree above 1% throughout its evolution and after correcting for the Milky Way interstellar polarization. The measurements are also above the maximum polarization degree expected from the SN’s host galaxy, showing that the object is intrinsically polarized. I will expose possible interpretations for our observations involving asymmetries in the explosion and/or the properties of the dust grains in the path of the light of SN 2017eaw.