  Gamma-ray bursts are cosmological sources emitting radiation from the
gamma-rays to the radio band. Substantial observational efforts have been
devoted to the study of GRBs during the prompt phase, i.e. the initial burst of
high-energy radiation, and during the longer-lasting afterglows. In spite of
many successes in interpreting these phenomena there are still several open key
questions about the fundamental emission processes, their energetics and the
environment. Moreover, independently of their modeling, GRB spectra are
remarkably simple, being satisfactorily fitted with power-laws, and therefore
offer a very valuable tool to probe the extragalactic background light
distribution affecting all high-energy observations of cosmological sources.
Observations carried out with Cherenkov telescopes, as MAGIC, can be
fundamental for all these scientific topics. GRB080430, being at a rather
moderate redshift, z~0.76, and well-studied in the optical, although observed
only a few hours after the high-energy event, is a good test case to evaluate
the perspective for late-afterglow observations with ground based GeV/TeV
observatories.
