Optical & infrared photometry of SN 2004eo

The light curves and spectra closely resemble those of the prototypical SN 1992A, and the luminosity at maximum (M_B_=-19.08) is close to the average for a Type Ia supernova (SN Ia). However, the ejected ^56^Ni mass derived by modelling the bolometric light curve (about 0.45M_{sun}_) lies near the lower limit of the ^56^Ni mass distribution observed in normal SNe Ia.

Accordingly, SN 2004eo shows a relatively rapid post-maximum decline in the light curve [{delta}m15(B)true=1.46], small expansion velocities in the ejecta and a depth ratio SiII{lambda}5972/SiII{lambda}6355 similar to that of SN 1992A. The physical properties of SN 2004eo cause it to fall very close to the boundary between the faint, low-velocity gradient and high-velocity gradient subgroups proposed by Benetti et al. Similar behaviour is seen in a few other SNe Ia.