SN 2011fu UBVRI griz JHKs light curves

The SN presents a double-peaked light curve (LC) similar to that of SN 1993J, although more luminous and with a longer cooling phase after the primary peak. The spectral evolution is also similar to SN 1993J's, with hydrogen dominating the spectra to ~40d, then helium gaining strength, and nebular emission lines appearing from ~60d post-explosion.

The velocities derived from the P-Cygni absorptions are overall similar to those of other type IIb SNe. We have found a strong similarity between the oxygen and magnesium line profiles at late times, which suggests that these lines are forming at the same location within the ejecta. The hydrodynamical modelling of the pseudo-bolometric LC and the observed photospheric velocities suggest that SN 2011fu was the explosion of an extended star (R~450R_{sun}_), in which 1.3x10^51^erg of kinetic energy were released and 0.15M_{sun}_ of 56Ni were synthesized.