  We present optical and near-infrared (IR) photometry and near-IR spectroscopy
of SN 2004am, the only optically detected supernova (SN) in M 82. These
demonstrate that SN 2004am was a highly reddened type II-P SN similar to the
low luminosity type II-P events such as SNe 1997D and 2005cs. We show that SN
2004am was located coincident with the obscured super star cluster M 82-L, and
from the cluster age infer a progenitor mass of 12 +7/-3 Msun. In addition to
this, we present a high spatial resolution Gemini-N K-band adaptive optics
image of the site of SN 2008iz and a second transient of uncertain nature, both
detected so far only at radio wavelengths. Using image subtraction techniques
together with archival data from the Hubble Space Telescope, we are able to
recover a near-IR transient source co-incident with both objects. We find the
likely extinction towards SN 2008iz to be not more than Av ~ 10. The nature of
the second transient remains elusive and we regard an extremely bright
microquasar in M 82 as the most plausible scenario.
