  All the giant planets in the solar system generate radio emission via the
electron cyclotron maser instability, most notably giving rise to Jupiter's
decametric emissions. An interaction with the solar wind is at least partially
responsible for all of these solar system electron cyclotron masers. HD80606b
is a giant planet with a highly eccentric orbit, leading to predictions that
its radio emission may be enhanced substantially near periastron. This paper
reports observations with the Low Frequency Array (LOFAR) of HD80606b near its
periastron in an effort to detect radio emissions generated by an electron
cyclotron maser instability in the planet's magnetosphere. The reported
observations are at frequencies between 30 MHz and 78 MHz, and they are
distinguished from most previous radio observations of extrasolar planets by
two factors: (i) They are at frequencies near 50 MHz, much closer to the
frequencies at which Jupiter emits (< 40 MHz) and lower than most previously
reported observations of extrasolar planets; and (ii) Sensitivities of
approximately a few millijanskys have been achieved, an order of magnitude or
more below nearly all previous extrasolar planet observations below 100 MHz. We
do not detect any radio emissions from HD80606b and use these observations to
place new constraints on its radio luminosity. We also revisit whether the
observations were conducted at a time when it was super-Alfvenic relative to
the host star's stellar wind, which experience from the solar system
illustrates is a state in which an electron cyclotron maser emission can be
sustained in a planet's magnetic polar regions.
