  Like the magnetised planets in our Solar System, magnetised exoplanets should
emit strongly at radio wavelengths. Radio emission directly traces the
planetary magnetic fields and radio detections can place constraints on the
physical parameters of these features. Large comparative studies of predicted
radio emission characteristics for the known population of exoplanets help to
identify what physical parameters could be key for producing bright, observable
radio emission. Since the last comparative study, many thousands of exoplanets
have been discovered. We report new estimates for the radio flux densities and
maximum emission frequencies for the current population of known exoplanets
orbiting pre-main sequence and main-sequence stars with spectral types F-M. The
set of exoplanets predicted to produce observable radio emission are Hot
Jupiters orbiting young stars. The youth of these system predicts strong
stellar magnetic fields and/or dense winds, which are key for producing bright,
observable radio emission. We use a new all-sky circular polarisation Murchison
Widefield Array survey to place sensitive limits on 200 MHz emission from
exoplanets, with $3\sigma$ values ranging from 4.0 - 45.0 mJy. Using a targeted
Giant Metre Wave Radio Telescope observing campaign, we also report a $3\sigma$
upper limit of 4.5 mJy on the radio emission from V830 Tau b, the first Hot
Jupiter to be discovered orbiting a pre-main sequence star. Our limit is the
first to be reported for the low-frequency radio emission from this source.

Earth and Planetary Astrophysics