Core collapse supernovae and starbursts
  Core-collapse supernovae are the endproducts of massive stars, and yield
radio events whose brightness depends on the intensity of the interaction
experienced by the supernova ejecta with the circumstellar presupernova wind
material. The fact that CCSNe are intrinsically radio supernovae --albeit with
a huge range of different radio powers-- and hence unaffected by dust
absorption, together with the high resolution and high sensitivity provided by
current VLBI arrays, has been exploited to directly image the radio brightness
structure of CCSNe in nearby (D <= 20 Mpc) galaxies. This has allowed to gain
insight into the physics of both CCSNe and of the circumstellar medium (CSM)
with which they interact. In addition, ultra-high-resolution,
ultra-high-sensitivity radio observations of CCSNe in Luminous and
Ultra-Luminous Infrared Galaxies (LIRGs and ULIRGs, respectively) in the local
Universe, can be used to directly measure of the current CCSN rate and star
formation rate.
  In this contribution, I give a brief overview of VLBI observations made of
some CCSNe in nearby galaxies, and then present some of the most relevant
results obtained with high-resolution radio observations of (U)LIRGs in the
local Universe, aimed at directly detecting CCSNe via their radio emission, and
thus determine their CCSN and star formation rates, independently of models.
This is of particular relevance, in view of the fact that our estimates of star
formation (and CCSN) rates in high-z starburst galaxies relies on standard
relationships between far-infrared luminosity and star-formation rate. In
particular, I will present recently obtained results with the e-EVN on the
nuclear region of Arp 299-A.
