Diversity in extinction laws of Type Ia supernovae measured between $0.2$ and $2\,\mu\mathrm{m}$

Understand

We present ultraviolet (UV) observations of six nearby Type~Ia supernovae (SNe~Ia) obtained with the Hubble Space Telescope, three of which were also observed in the near-IR (NIR) with Wide-Field Camera~3.

• UV observations with the Swift satellite, as well as ground-based optical and near-infrared data provide complementary information.
• The combined data-set covers the wavelength range $0.2$--$2~\mu$m.
• By also including archival data of SN 2014J, we analyse a sample spanning observed colour excesses up to $E(B-V)=1.4~$mag.